/*
  * H.26L/H.264/AVC/JVT/14496-10/... decoder
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * @file

  * H.264 / AVC / MPEG-4 part10 codec.

  * @author Michael Niedermayer <michaelni@gmx.at>
  */
 
 #include "libavutil/avassert.h"

 #include "libavutil/display.h"

 #include "libavutil/imgutils.h"

 #include "libavutil/stereo3d.h"

 #include "libavutil/timer.h"
 #include "internal.h"
 #include "cabac.h"
 #include "cabac_functions.h"
 #include "error_resilience.h"
 #include "avcodec.h"

 #include "h264.h"

 #include "h264dec.h"

 #include "h264data.h"
 #include "h264chroma.h"
 #include "h264_mvpred.h"

 #include "h264_ps.h"

 #include "golomb.h"
 #include "mathops.h"
 #include "mpegutils.h"
 #include "rectangle.h"
 #include "thread.h"
 

 static const uint8_t field_scan[16+1] = {

     0 + 0 * 4, 0 + 1 * 4, 1 + 0 * 4, 0 + 2 * 4,
     0 + 3 * 4, 1 + 1 * 4, 1 + 2 * 4, 1 + 3 * 4,
     2 + 0 * 4, 2 + 1 * 4, 2 + 2 * 4, 2 + 3 * 4,
     3 + 0 * 4, 3 + 1 * 4, 3 + 2 * 4, 3 + 3 * 4,
 };
 

 static const uint8_t field_scan8x8[64+1] = {

     0 + 0 * 8, 0 + 1 * 8, 0 + 2 * 8, 1 + 0 * 8,
     1 + 1 * 8, 0 + 3 * 8, 0 + 4 * 8, 1 + 2 * 8,
     2 + 0 * 8, 1 + 3 * 8, 0 + 5 * 8, 0 + 6 * 8,
     0 + 7 * 8, 1 + 4 * 8, 2 + 1 * 8, 3 + 0 * 8,
     2 + 2 * 8, 1 + 5 * 8, 1 + 6 * 8, 1 + 7 * 8,
     2 + 3 * 8, 3 + 1 * 8, 4 + 0 * 8, 3 + 2 * 8,
     2 + 4 * 8, 2 + 5 * 8, 2 + 6 * 8, 2 + 7 * 8,
     3 + 3 * 8, 4 + 1 * 8, 5 + 0 * 8, 4 + 2 * 8,
     3 + 4 * 8, 3 + 5 * 8, 3 + 6 * 8, 3 + 7 * 8,
     4 + 3 * 8, 5 + 1 * 8, 6 + 0 * 8, 5 + 2 * 8,
     4 + 4 * 8, 4 + 5 * 8, 4 + 6 * 8, 4 + 7 * 8,
     5 + 3 * 8, 6 + 1 * 8, 6 + 2 * 8, 5 + 4 * 8,
     5 + 5 * 8, 5 + 6 * 8, 5 + 7 * 8, 6 + 3 * 8,
     7 + 0 * 8, 7 + 1 * 8, 6 + 4 * 8, 6 + 5 * 8,
     6 + 6 * 8, 6 + 7 * 8, 7 + 2 * 8, 7 + 3 * 8,
     7 + 4 * 8, 7 + 5 * 8, 7 + 6 * 8, 7 + 7 * 8,
 };
 

 static const uint8_t field_scan8x8_cavlc[64+1] = {

     0 + 0 * 8, 1 + 1 * 8, 2 + 0 * 8, 0 + 7 * 8,
     2 + 2 * 8, 2 + 3 * 8, 2 + 4 * 8, 3 + 3 * 8,
     3 + 4 * 8, 4 + 3 * 8, 4 + 4 * 8, 5 + 3 * 8,
     5 + 5 * 8, 7 + 0 * 8, 6 + 6 * 8, 7 + 4 * 8,
     0 + 1 * 8, 0 + 3 * 8, 1 + 3 * 8, 1 + 4 * 8,
     1 + 5 * 8, 3 + 1 * 8, 2 + 5 * 8, 4 + 1 * 8,
     3 + 5 * 8, 5 + 1 * 8, 4 + 5 * 8, 6 + 1 * 8,
     5 + 6 * 8, 7 + 1 * 8, 6 + 7 * 8, 7 + 5 * 8,
     0 + 2 * 8, 0 + 4 * 8, 0 + 5 * 8, 2 + 1 * 8,
     1 + 6 * 8, 4 + 0 * 8, 2 + 6 * 8, 5 + 0 * 8,
     3 + 6 * 8, 6 + 0 * 8, 4 + 6 * 8, 6 + 2 * 8,
     5 + 7 * 8, 6 + 4 * 8, 7 + 2 * 8, 7 + 6 * 8,
     1 + 0 * 8, 1 + 2 * 8, 0 + 6 * 8, 3 + 0 * 8,
     1 + 7 * 8, 3 + 2 * 8, 2 + 7 * 8, 4 + 2 * 8,
     3 + 7 * 8, 5 + 2 * 8, 4 + 7 * 8, 5 + 4 * 8,
     6 + 3 * 8, 6 + 5 * 8, 7 + 3 * 8, 7 + 7 * 8,
 };
 
 // zigzag_scan8x8_cavlc[i] = zigzag_scan8x8[(i/4) + 16*(i%4)]

 static const uint8_t zigzag_scan8x8_cavlc[64+1] = {

     0 + 0 * 8, 1 + 1 * 8, 1 + 2 * 8, 2 + 2 * 8,
     4 + 1 * 8, 0 + 5 * 8, 3 + 3 * 8, 7 + 0 * 8,
     3 + 4 * 8, 1 + 7 * 8, 5 + 3 * 8, 6 + 3 * 8,
     2 + 7 * 8, 6 + 4 * 8, 5 + 6 * 8, 7 + 5 * 8,
     1 + 0 * 8, 2 + 0 * 8, 0 + 3 * 8, 3 + 1 * 8,
     3 + 2 * 8, 0 + 6 * 8, 4 + 2 * 8, 6 + 1 * 8,
     2 + 5 * 8, 2 + 6 * 8, 6 + 2 * 8, 5 + 4 * 8,
     3 + 7 * 8, 7 + 3 * 8, 4 + 7 * 8, 7 + 6 * 8,
     0 + 1 * 8, 3 + 0 * 8, 0 + 4 * 8, 4 + 0 * 8,
     2 + 3 * 8, 1 + 5 * 8, 5 + 1 * 8, 5 + 2 * 8,
     1 + 6 * 8, 3 + 5 * 8, 7 + 1 * 8, 4 + 5 * 8,
     4 + 6 * 8, 7 + 4 * 8, 5 + 7 * 8, 6 + 7 * 8,
     0 + 2 * 8, 2 + 1 * 8, 1 + 3 * 8, 5 + 0 * 8,
     1 + 4 * 8, 2 + 4 * 8, 6 + 0 * 8, 4 + 3 * 8,
     0 + 7 * 8, 4 + 4 * 8, 7 + 2 * 8, 3 + 6 * 8,
     5 + 5 * 8, 6 + 5 * 8, 6 + 6 * 8, 7 + 7 * 8,
 };
 
 static void release_unused_pictures(H264Context *h, int remove_current)
 {
     int i;
 
     /* release non reference frames */
     for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {

         if (h->DPB[i].f->buf[0] && !h->DPB[i].reference &&

             (remove_current || &h->DPB[i] != h->cur_pic_ptr)) {
             ff_h264_unref_picture(h, &h->DPB[i]);
         }
     }
 }
 

 static int alloc_scratch_buffers(H264SliceContext *sl, int linesize)

 {

     const H264Context *h = sl->h264;

     int alloc_size = FFALIGN(FFABS(linesize) + 32, 32);
 

     av_fast_malloc(&sl->bipred_scratchpad, &sl->bipred_scratchpad_allocated, 16 * 6 * alloc_size);

     // edge emu needs blocksize + filter length - 1

     // (= 21x21 for  H.264)

     av_fast_malloc(&sl->edge_emu_buffer, &sl->edge_emu_buffer_allocated, alloc_size * 2 * 21);

     av_fast_mallocz(&sl->top_borders[0], &sl->top_borders_allocated[0],

                    h->mb_width * 16 * 3 * sizeof(uint8_t) * 2);

     av_fast_mallocz(&sl->top_borders[1], &sl->top_borders_allocated[1],

                    h->mb_width * 16 * 3 * sizeof(uint8_t) * 2);
 
     if (!sl->bipred_scratchpad || !sl->edge_emu_buffer ||
         !sl->top_borders[0]    || !sl->top_borders[1]) {

         av_freep(&sl->bipred_scratchpad);
         av_freep(&sl->edge_emu_buffer);

         av_freep(&sl->top_borders[0]);
         av_freep(&sl->top_borders[1]);
 

         sl->bipred_scratchpad_allocated = 0;
         sl->edge_emu_buffer_allocated   = 0;

         sl->top_borders_allocated[0]    = 0;
         sl->top_borders_allocated[1]    = 0;

         return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int init_table_pools(H264Context *h)
 {
     const int big_mb_num    = h->mb_stride * (h->mb_height + 1) + 1;
     const int mb_array_size = h->mb_stride * h->mb_height;
     const int b4_stride     = h->mb_width * 4 + 1;
     const int b4_array_size = b4_stride * h->mb_height * 4;
 
     h->qscale_table_pool = av_buffer_pool_init(big_mb_num + h->mb_stride,
                                                av_buffer_allocz);
     h->mb_type_pool      = av_buffer_pool_init((big_mb_num + h->mb_stride) *
                                                sizeof(uint32_t), av_buffer_allocz);

     h->motion_val_pool   = av_buffer_pool_init(2 * (b4_array_size + 4) *
                                                sizeof(int16_t), av_buffer_allocz);
     h->ref_index_pool    = av_buffer_pool_init(4 * mb_array_size, av_buffer_allocz);

 
     if (!h->qscale_table_pool || !h->mb_type_pool || !h->motion_val_pool ||
         !h->ref_index_pool) {
         av_buffer_pool_uninit(&h->qscale_table_pool);
         av_buffer_pool_uninit(&h->mb_type_pool);
         av_buffer_pool_uninit(&h->motion_val_pool);
         av_buffer_pool_uninit(&h->ref_index_pool);
         return AVERROR(ENOMEM);
     }
 
     return 0;
 }
 
 static int alloc_picture(H264Context *h, H264Picture *pic)
 {
     int i, ret = 0;
 

     av_assert0(!pic->f->data[0]);

     pic->tf.f = pic->f;

     ret = ff_thread_get_buffer(h->avctx, &pic->tf, pic->reference ?
                                                    AV_GET_BUFFER_FLAG_REF : 0);
     if (ret < 0)
         goto fail;
 

     pic->crop     = h->ps.sps->crop;
     pic->crop_top = h->ps.sps->crop_top;
     pic->crop_left= h->ps.sps->crop_left;

 
     if (h->avctx->hwaccel) {
         const AVHWAccel *hwaccel = h->avctx->hwaccel;
         av_assert0(!pic->hwaccel_picture_private);

         if (hwaccel->frame_priv_data_size) {
             pic->hwaccel_priv_buf = av_buffer_allocz(hwaccel->frame_priv_data_size);

             if (!pic->hwaccel_priv_buf)
                 return AVERROR(ENOMEM);
             pic->hwaccel_picture_private = pic->hwaccel_priv_buf->data;
         }
     }

     if (CONFIG_GRAY && !h->avctx->hwaccel && h->flags & AV_CODEC_FLAG_GRAY && pic->f->data[2]) {

         int h_chroma_shift, v_chroma_shift;

         av_pix_fmt_get_chroma_sub_sample(pic->f->format,

                                          &h_chroma_shift, &v_chroma_shift);
 

         for(i=0; i<AV_CEIL_RSHIFT(pic->f->height, v_chroma_shift); i++) {

             memset(pic->f->data[1] + pic->f->linesize[1]*i,

                    0x80, AV_CEIL_RSHIFT(pic->f->width, h_chroma_shift));

             memset(pic->f->data[2] + pic->f->linesize[2]*i,

                    0x80, AV_CEIL_RSHIFT(pic->f->width, h_chroma_shift));

         }
     }

 
     if (!h->qscale_table_pool) {
         ret = init_table_pools(h);
         if (ret < 0)
             goto fail;
     }
 
     pic->qscale_table_buf = av_buffer_pool_get(h->qscale_table_pool);
     pic->mb_type_buf      = av_buffer_pool_get(h->mb_type_pool);
     if (!pic->qscale_table_buf || !pic->mb_type_buf)
         goto fail;
 
     pic->mb_type      = (uint32_t*)pic->mb_type_buf->data + 2 * h->mb_stride + 1;
     pic->qscale_table = pic->qscale_table_buf->data + 2 * h->mb_stride + 1;
 
     for (i = 0; i < 2; i++) {
         pic->motion_val_buf[i] = av_buffer_pool_get(h->motion_val_pool);
         pic->ref_index_buf[i]  = av_buffer_pool_get(h->ref_index_pool);
         if (!pic->motion_val_buf[i] || !pic->ref_index_buf[i])
             goto fail;
 
         pic->motion_val[i] = (int16_t (*)[2])pic->motion_val_buf[i]->data + 4;
         pic->ref_index[i]  = pic->ref_index_buf[i]->data;
     }
 
     return 0;
 fail:
     ff_h264_unref_picture(h, pic);
     return (ret < 0) ? ret : AVERROR(ENOMEM);
 }
 
 static inline int pic_is_unused(H264Context *h, H264Picture *pic)
 {

     if (!pic->f->buf[0])

         return 1;
     return 0;
 }
 
 static int find_unused_picture(H264Context *h)
 {
     int i;
 
     for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {
         if (pic_is_unused(h, &h->DPB[i]))
             break;
     }
     if (i == H264_MAX_PICTURE_COUNT)
         return AVERROR_INVALIDDATA;
 
     return i;
 }
 
 

 #define IN_RANGE(a, b, size) (((void*)(a) >= (void*)(b)) && ((void*)(a) < (void*)((b) + (size))))

 #define REBASE_PICTURE(pic, new_ctx, old_ctx)             \

     (((pic) && (pic) >= (old_ctx)->DPB &&                       \
       (pic) < (old_ctx)->DPB + H264_MAX_PICTURE_COUNT) ?          \
      &(new_ctx)->DPB[(pic) - (old_ctx)->DPB] : NULL)

 
 static void copy_picture_range(H264Picture **to, H264Picture **from, int count,
                                H264Context *new_base,
                                H264Context *old_base)
 {
     int i;
 
     for (i = 0; i < count; i++) {

         av_assert1(!from[i] ||
                    IN_RANGE(from[i], old_base, 1) ||
                    IN_RANGE(from[i], old_base->DPB, H264_MAX_PICTURE_COUNT));

         to[i] = REBASE_PICTURE(from[i], new_base, old_base);
     }
 }
 

 static int h264_slice_header_init(H264Context *h);

 
 int ff_h264_update_thread_context(AVCodecContext *dst,
                                   const AVCodecContext *src)
 {
     H264Context *h = dst->priv_data, *h1 = src->priv_data;
     int inited = h->context_initialized, err = 0;

     int need_reinit = 0;

     int i, ret;
 

     if (dst == src)

         return 0;
 

     // We can't fail if SPS isn't set at it breaks current skip_frame code
     //if (!h1->ps.sps)
     //    return AVERROR_INVALIDDATA;

     if (inited &&
         (h->width                 != h1->width                 ||
          h->height                != h1->height                ||
          h->mb_width              != h1->mb_width              ||
          h->mb_height             != h1->mb_height             ||

          !h->ps.sps                                            ||
          h->ps.sps->bit_depth_luma    != h1->ps.sps->bit_depth_luma    ||
          h->ps.sps->chroma_format_idc != h1->ps.sps->chroma_format_idc ||
          h->ps.sps->colorspace        != h1->ps.sps->colorspace)) {

         need_reinit = 1;

     }

 
     /* copy block_offset since frame_start may not be called */
     memcpy(h->block_offset, h1->block_offset, sizeof(h->block_offset));

     // SPS/PPS

     for (i = 0; i < FF_ARRAY_ELEMS(h->ps.sps_list); i++) {
         av_buffer_unref(&h->ps.sps_list[i]);
         if (h1->ps.sps_list[i]) {
             h->ps.sps_list[i] = av_buffer_ref(h1->ps.sps_list[i]);
             if (!h->ps.sps_list[i])
                 return AVERROR(ENOMEM);
         }
     }
     for (i = 0; i < FF_ARRAY_ELEMS(h->ps.pps_list); i++) {
         av_buffer_unref(&h->ps.pps_list[i]);
         if (h1->ps.pps_list[i]) {
             h->ps.pps_list[i] = av_buffer_ref(h1->ps.pps_list[i]);
             if (!h->ps.pps_list[i])
                 return AVERROR(ENOMEM);
         }
     }
 

     av_buffer_unref(&h->ps.pps_ref);
     av_buffer_unref(&h->ps.sps_ref);
     h->ps.pps = NULL;
     h->ps.sps = NULL;
     if (h1->ps.pps_ref) {
         h->ps.pps_ref = av_buffer_ref(h1->ps.pps_ref);
         if (!h->ps.pps_ref)
             return AVERROR(ENOMEM);

         h->ps.pps = (const PPS*)h->ps.pps_ref->data;

     }
     if (h1->ps.sps_ref) {
         h->ps.sps_ref = av_buffer_ref(h1->ps.sps_ref);
         if (!h->ps.sps_ref)
             return AVERROR(ENOMEM);

         h->ps.sps = (const SPS*)h->ps.sps_ref->data;

     }

     if (need_reinit || !inited) {
         h->width     = h1->width;
         h->height    = h1->height;
         h->mb_height = h1->mb_height;
         h->mb_width  = h1->mb_width;
         h->mb_num    = h1->mb_num;
         h->mb_stride = h1->mb_stride;
         h->b_stride  = h1->b_stride;
 

         if (h->context_initialized || h1->context_initialized) {
             if ((err = h264_slice_header_init(h)) < 0) {
                 av_log(h->avctx, AV_LOG_ERROR, "h264_slice_header_init() failed");
                 return err;
             }

         }

         /* copy block_offset since frame_start may not be called */
         memcpy(h->block_offset, h1->block_offset, sizeof(h->block_offset));

     }
 
     h->avctx->coded_height  = h1->avctx->coded_height;
     h->avctx->coded_width   = h1->avctx->coded_width;
     h->avctx->width         = h1->avctx->width;
     h->avctx->height        = h1->avctx->height;
     h->coded_picture_number = h1->coded_picture_number;
     h->first_field          = h1->first_field;
     h->picture_structure    = h1->picture_structure;

     h->mb_aff_frame         = h1->mb_aff_frame;

     h->droppable            = h1->droppable;

     h->backup_width         = h1->backup_width;
     h->backup_height        = h1->backup_height;
     h->backup_pix_fmt       = h1->backup_pix_fmt;

 
     for (i = 0; i < H264_MAX_PICTURE_COUNT; i++) {
         ff_h264_unref_picture(h, &h->DPB[i]);

         if (h1->DPB[i].f->buf[0] &&

             (ret = ff_h264_ref_picture(h, &h->DPB[i], &h1->DPB[i])) < 0)
             return ret;
     }
 
     h->cur_pic_ptr = REBASE_PICTURE(h1->cur_pic_ptr, h, h1);
     ff_h264_unref_picture(h, &h->cur_pic);

     if (h1->cur_pic.f->buf[0]) {

         ret = ff_h264_ref_picture(h, &h->cur_pic, &h1->cur_pic);
         if (ret < 0)
             return ret;
     }

     h->enable_er       = h1->enable_er;

     h->workaround_bugs = h1->workaround_bugs;
     h->droppable       = h1->droppable;
 
     // extradata/NAL handling
     h->is_avc = h1->is_avc;

     h->nal_length_size = h1->nal_length_size;

     h->sei.unregistered.x264_build = h1->sei.unregistered.x264_build;

     memcpy(&h->poc,        &h1->poc,        sizeof(h->poc));
 

     memcpy(h->default_ref, h1->default_ref, sizeof(h->default_ref));

     memcpy(h->short_ref,   h1->short_ref,   sizeof(h->short_ref));
     memcpy(h->long_ref,    h1->long_ref,    sizeof(h->long_ref));
     memcpy(h->delayed_pic, h1->delayed_pic, sizeof(h->delayed_pic));
     memcpy(h->last_pocs,   h1->last_pocs,   sizeof(h->last_pocs));
 
     h->next_output_pic   = h1->next_output_pic;
     h->next_outputed_poc = h1->next_outputed_poc;
 
     memcpy(h->mmco, h1->mmco, sizeof(h->mmco));

     h->nb_mmco         = h1->nb_mmco;

     h->mmco_reset      = h1->mmco_reset;

     h->explicit_ref_marking = h1->explicit_ref_marking;

     h->long_ref_count  = h1->long_ref_count;
     h->short_ref_count = h1->short_ref_count;

 
     copy_picture_range(h->short_ref, h1->short_ref, 32, h, h1);
     copy_picture_range(h->long_ref, h1->long_ref, 32, h, h1);
     copy_picture_range(h->delayed_pic, h1->delayed_pic,
                        MAX_DELAYED_PIC_COUNT + 2, h, h1);
 

     h->frame_recovered       = h1->frame_recovered;

 
     if (!h->cur_pic_ptr)
         return 0;
 
     if (!h->droppable) {

         err = ff_h264_execute_ref_pic_marking(h);

         h->poc.prev_poc_msb = h->poc.poc_msb;
         h->poc.prev_poc_lsb = h->poc.poc_lsb;

     }

     h->poc.prev_frame_num_offset = h->poc.frame_num_offset;
     h->poc.prev_frame_num        = h->poc.frame_num;

 
     h->recovery_frame        = h1->recovery_frame;
 
     return err;
 }
 
 static int h264_frame_start(H264Context *h)
 {
     H264Picture *pic;
     int i, ret;
     const int pixel_shift = h->pixel_shift;

     int c[4] = {

         1<<(h->ps.sps->bit_depth_luma-1),
         1<<(h->ps.sps->bit_depth_chroma-1),
         1<<(h->ps.sps->bit_depth_chroma-1),

         -1
     };
 
     if (!ff_thread_can_start_frame(h->avctx)) {
         av_log(h->avctx, AV_LOG_ERROR, "Attempt to start a frame outside SETUP state\n");
         return -1;
     }

 
     release_unused_pictures(h, 1);
     h->cur_pic_ptr = NULL;
 
     i = find_unused_picture(h);
     if (i < 0) {
         av_log(h->avctx, AV_LOG_ERROR, "no frame buffer available\n");
         return i;
     }
     pic = &h->DPB[i];
 
     pic->reference              = h->droppable ? 0 : h->picture_structure;

     pic->f->coded_picture_number = h->coded_picture_number++;

     pic->field_picture          = h->picture_structure != PICT_FRAME;

     pic->frame_num               = h->poc.frame_num;

     /*
      * Zero key_frame here; IDR markings per slice in frame or fields are ORed
      * in later.
      * See decode_nal_units().
      */

     pic->f->key_frame = 0;

     pic->mmco_reset  = 0;
     pic->recovered   = 0;

     pic->invalid_gap = 0;

     pic->sei_recovery_frame_cnt = h->sei.recovery_point.recovery_frame_cnt;

     pic->f->pict_type = h->slice_ctx[0].slice_type;
 

     if ((ret = alloc_picture(h, pic)) < 0)
         return ret;

     if(!h->frame_recovered && !h->avctx->hwaccel
 #if FF_API_CAP_VDPAU
        && !(h->avctx->codec->capabilities & AV_CODEC_CAP_HWACCEL_VDPAU)
 #endif
        )

         ff_color_frame(pic->f, c);

 
     h->cur_pic_ptr = pic;
     ff_h264_unref_picture(h, &h->cur_pic);

     if (CONFIG_ERROR_RESILIENCE) {

         ff_h264_set_erpic(&h->slice_ctx[0].er.cur_pic, NULL);

     }
 

     if ((ret = ff_h264_ref_picture(h, &h->cur_pic, h->cur_pic_ptr)) < 0)
         return ret;
 

     for (i = 0; i < h->nb_slice_ctx; i++) {

         h->slice_ctx[i].linesize   = h->cur_pic_ptr->f->linesize[0];
         h->slice_ctx[i].uvlinesize = h->cur_pic_ptr->f->linesize[1];

     }
 

     if (CONFIG_ERROR_RESILIENCE && h->enable_er) {

         ff_er_frame_start(&h->slice_ctx[0].er);

         ff_h264_set_erpic(&h->slice_ctx[0].er.last_pic, NULL);
         ff_h264_set_erpic(&h->slice_ctx[0].er.next_pic, NULL);

     }

 
     for (i = 0; i < 16; i++) {

         h->block_offset[i]           = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 4 * pic->f->linesize[0] * ((scan8[i] - scan8[0]) >> 3);
         h->block_offset[48 + i]      = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * pic->f->linesize[0] * ((scan8[i] - scan8[0]) >> 3);

     }
     for (i = 0; i < 16; i++) {
         h->block_offset[16 + i]      =

         h->block_offset[32 + i]      = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 4 * pic->f->linesize[1] * ((scan8[i] - scan8[0]) >> 3);

         h->block_offset[48 + 16 + i] =

         h->block_offset[48 + 32 + i] = (4 * ((scan8[i] - scan8[0]) & 7) << pixel_shift) + 8 * pic->f->linesize[1] * ((scan8[i] - scan8[0]) >> 3);

     }
 
     /* We mark the current picture as non-reference after allocating it, so
      * that if we break out due to an error it can be released automatically

      * in the next ff_mpv_frame_start().

      */
     h->cur_pic_ptr->reference = 0;
 
     h->cur_pic_ptr->field_poc[0] = h->cur_pic_ptr->field_poc[1] = INT_MAX;
 
     h->next_output_pic = NULL;
 

     h->postpone_filter = 0;
 

     h->mb_aff_frame = h->ps.sps->mb_aff && (h->picture_structure == PICT_FRAME);
 

     assert(h->cur_pic_ptr->long_ref == 0);
 
     return 0;
 }
 

 static av_always_inline void backup_mb_border(const H264Context *h, H264SliceContext *sl,

                                               uint8_t *src_y,

                                               uint8_t *src_cb, uint8_t *src_cr,
                                               int linesize, int uvlinesize,
                                               int simple)
 {
     uint8_t *top_border;
     int top_idx = 1;
     const int pixel_shift = h->pixel_shift;
     int chroma444 = CHROMA444(h);
     int chroma422 = CHROMA422(h);
 
     src_y  -= linesize;
     src_cb -= uvlinesize;
     src_cr -= uvlinesize;
 
     if (!simple && FRAME_MBAFF(h)) {

         if (sl->mb_y & 1) {

             if (!MB_MBAFF(sl)) {

                 top_border = sl->top_borders[0][sl->mb_x];

                 AV_COPY128(top_border, src_y + 15 * linesize);
                 if (pixel_shift)
                     AV_COPY128(top_border + 16, src_y + 15 * linesize + 16);

                 if (simple || !CONFIG_GRAY || !(h->flags & AV_CODEC_FLAG_GRAY)) {

                     if (chroma444) {
                         if (pixel_shift) {
                             AV_COPY128(top_border + 32, src_cb + 15 * uvlinesize);
                             AV_COPY128(top_border + 48, src_cb + 15 * uvlinesize + 16);
                             AV_COPY128(top_border + 64, src_cr + 15 * uvlinesize);
                             AV_COPY128(top_border + 80, src_cr + 15 * uvlinesize + 16);
                         } else {
                             AV_COPY128(top_border + 16, src_cb + 15 * uvlinesize);
                             AV_COPY128(top_border + 32, src_cr + 15 * uvlinesize);
                         }
                     } else if (chroma422) {
                         if (pixel_shift) {
                             AV_COPY128(top_border + 32, src_cb + 15 * uvlinesize);
                             AV_COPY128(top_border + 48, src_cr + 15 * uvlinesize);
                         } else {
                             AV_COPY64(top_border + 16, src_cb + 15 * uvlinesize);
                             AV_COPY64(top_border + 24, src_cr + 15 * uvlinesize);
                         }
                     } else {
                         if (pixel_shift) {
                             AV_COPY128(top_border + 32, src_cb + 7 * uvlinesize);
                             AV_COPY128(top_border + 48, src_cr + 7 * uvlinesize);
                         } else {
                             AV_COPY64(top_border + 16, src_cb + 7 * uvlinesize);
                             AV_COPY64(top_border + 24, src_cr + 7 * uvlinesize);
                         }
                     }
                 }
             }

         } else if (MB_MBAFF(sl)) {

             top_idx = 0;
         } else
             return;
     }
 

     top_border = sl->top_borders[top_idx][sl->mb_x];

     /* There are two lines saved, the line above the top macroblock
      * of a pair, and the line above the bottom macroblock. */
     AV_COPY128(top_border, src_y + 16 * linesize);
     if (pixel_shift)
         AV_COPY128(top_border + 16, src_y + 16 * linesize + 16);
 

     if (simple || !CONFIG_GRAY || !(h->flags & AV_CODEC_FLAG_GRAY)) {

         if (chroma444) {
             if (pixel_shift) {
                 AV_COPY128(top_border + 32, src_cb + 16 * linesize);
                 AV_COPY128(top_border + 48, src_cb + 16 * linesize + 16);
                 AV_COPY128(top_border + 64, src_cr + 16 * linesize);
                 AV_COPY128(top_border + 80, src_cr + 16 * linesize + 16);
             } else {
                 AV_COPY128(top_border + 16, src_cb + 16 * linesize);
                 AV_COPY128(top_border + 32, src_cr + 16 * linesize);
             }
         } else if (chroma422) {
             if (pixel_shift) {
                 AV_COPY128(top_border + 32, src_cb + 16 * uvlinesize);
                 AV_COPY128(top_border + 48, src_cr + 16 * uvlinesize);
             } else {
                 AV_COPY64(top_border + 16, src_cb + 16 * uvlinesize);
                 AV_COPY64(top_border + 24, src_cr + 16 * uvlinesize);
             }
         } else {
             if (pixel_shift) {
                 AV_COPY128(top_border + 32, src_cb + 8 * uvlinesize);
                 AV_COPY128(top_border + 48, src_cr + 8 * uvlinesize);
             } else {
                 AV_COPY64(top_border + 16, src_cb + 8 * uvlinesize);
                 AV_COPY64(top_border + 24, src_cr + 8 * uvlinesize);
             }
         }
     }
 }
 
 /**
  * Initialize implicit_weight table.
  * @param field  0/1 initialize the weight for interlaced MBAFF
  *                -1 initializes the rest
  */

 static void implicit_weight_table(const H264Context *h, H264SliceContext *sl, int field)

 {
     int ref0, ref1, i, cur_poc, ref_start, ref_count0, ref_count1;
 
     for (i = 0; i < 2; i++) {

         sl->pwt.luma_weight_flag[i]   = 0;
         sl->pwt.chroma_weight_flag[i] = 0;

     }
 
     if (field < 0) {
         if (h->picture_structure == PICT_FRAME) {
             cur_poc = h->cur_pic_ptr->poc;
         } else {
             cur_poc = h->cur_pic_ptr->field_poc[h->picture_structure - 1];
         }

         if (sl->ref_count[0] == 1 && sl->ref_count[1] == 1 && !FRAME_MBAFF(h) &&

             sl->ref_list[0][0].poc + (int64_t)sl->ref_list[1][0].poc == 2LL * cur_poc) {

             sl->pwt.use_weight        = 0;
             sl->pwt.use_weight_chroma = 0;

             return;
         }
         ref_start  = 0;

         ref_count0 = sl->ref_count[0];
         ref_count1 = sl->ref_count[1];

     } else {
         cur_poc    = h->cur_pic_ptr->field_poc[field];
         ref_start  = 16;

         ref_count0 = 16 + 2 * sl->ref_count[0];
         ref_count1 = 16 + 2 * sl->ref_count[1];

     }
 

     sl->pwt.use_weight               = 2;
     sl->pwt.use_weight_chroma        = 2;
     sl->pwt.luma_log2_weight_denom   = 5;
     sl->pwt.chroma_log2_weight_denom = 5;

 
     for (ref0 = ref_start; ref0 < ref_count0; ref0++) {

         int64_t poc0 = sl->ref_list[0][ref0].poc;

         for (ref1 = ref_start; ref1 < ref_count1; ref1++) {
             int w = 32;

             if (!sl->ref_list[0][ref0].parent->long_ref && !sl->ref_list[1][ref1].parent->long_ref) {

                 int poc1 = sl->ref_list[1][ref1].poc;

                 int td   = av_clip_int8(poc1 - poc0);

                 if (td) {

                     int tb = av_clip_int8(cur_poc - poc0);

                     int tx = (16384 + (FFABS(td) >> 1)) / td;
                     int dist_scale_factor = (tb * tx + 32) >> 8;
                     if (dist_scale_factor >= -64 && dist_scale_factor <= 128)
                         w = 64 - dist_scale_factor;
                 }
             }
             if (field < 0) {

                 sl->pwt.implicit_weight[ref0][ref1][0] =
                 sl->pwt.implicit_weight[ref0][ref1][1] = w;

             } else {

                 sl->pwt.implicit_weight[ref0][ref1][field] = w;

             }
         }
     }
 }
 
 /**
  * initialize scan tables
  */
 static void init_scan_tables(H264Context *h)
 {
     int i;
     for (i = 0; i < 16; i++) {

 #define TRANSPOSE(x) ((x) >> 2) | (((x) << 2) & 0xF)

         h->zigzag_scan[i] = TRANSPOSE(ff_zigzag_scan[i]);

         h->field_scan[i]  = TRANSPOSE(field_scan[i]);
 #undef TRANSPOSE
     }
     for (i = 0; i < 64; i++) {

 #define TRANSPOSE(x) ((x) >> 3) | (((x) & 7) << 3)

         h->zigzag_scan8x8[i]       = TRANSPOSE(ff_zigzag_direct[i]);
         h->zigzag_scan8x8_cavlc[i] = TRANSPOSE(zigzag_scan8x8_cavlc[i]);
         h->field_scan8x8[i]        = TRANSPOSE(field_scan8x8[i]);
         h->field_scan8x8_cavlc[i]  = TRANSPOSE(field_scan8x8_cavlc[i]);
 #undef TRANSPOSE
     }

     if (h->ps.sps->transform_bypass) { // FIXME same ugly

         memcpy(h->zigzag_scan_q0          , ff_zigzag_scan          , sizeof(h->zigzag_scan_q0         ));

         memcpy(h->zigzag_scan8x8_q0       , ff_zigzag_direct        , sizeof(h->zigzag_scan8x8_q0      ));
         memcpy(h->zigzag_scan8x8_cavlc_q0 , zigzag_scan8x8_cavlc    , sizeof(h->zigzag_scan8x8_cavlc_q0));
         memcpy(h->field_scan_q0           , field_scan              , sizeof(h->field_scan_q0          ));
         memcpy(h->field_scan8x8_q0        , field_scan8x8           , sizeof(h->field_scan8x8_q0       ));
         memcpy(h->field_scan8x8_cavlc_q0  , field_scan8x8_cavlc     , sizeof(h->field_scan8x8_cavlc_q0 ));

     } else {

         memcpy(h->zigzag_scan_q0          , h->zigzag_scan          , sizeof(h->zigzag_scan_q0         ));
         memcpy(h->zigzag_scan8x8_q0       , h->zigzag_scan8x8       , sizeof(h->zigzag_scan8x8_q0      ));
         memcpy(h->zigzag_scan8x8_cavlc_q0 , h->zigzag_scan8x8_cavlc , sizeof(h->zigzag_scan8x8_cavlc_q0));
         memcpy(h->field_scan_q0           , h->field_scan           , sizeof(h->field_scan_q0          ));
         memcpy(h->field_scan8x8_q0        , h->field_scan8x8        , sizeof(h->field_scan8x8_q0       ));
         memcpy(h->field_scan8x8_cavlc_q0  , h->field_scan8x8_cavlc  , sizeof(h->field_scan8x8_cavlc_q0 ));

     }
 }
 

 static enum AVPixelFormat get_pixel_format(H264Context *h, int force_callback)

 {

 #define HWACCEL_MAX (CONFIG_H264_DXVA2_HWACCEL + \

                      CONFIG_H264_D3D11VA_HWACCEL + \

                      CONFIG_H264_VAAPI_HWACCEL + \
                      (CONFIG_H264_VDA_HWACCEL * 2) + \

                      CONFIG_H264_VIDEOTOOLBOX_HWACCEL + \

                      CONFIG_H264_VDPAU_HWACCEL)
     enum AVPixelFormat pix_fmts[HWACCEL_MAX + 2], *fmt = pix_fmts;

     const enum AVPixelFormat *choices = pix_fmts;

     int i;

     switch (h->ps.sps->bit_depth_luma) {

     case 9:
         if (CHROMA444(h)) {
             if (h->avctx->colorspace == AVCOL_SPC_RGB) {

                 *fmt++ = AV_PIX_FMT_GBRP9;

             } else

                 *fmt++ = AV_PIX_FMT_YUV444P9;

         } else if (CHROMA422(h))

             *fmt++ = AV_PIX_FMT_YUV422P9;

         else

             *fmt++ = AV_PIX_FMT_YUV420P9;

         break;
     case 10:
         if (CHROMA444(h)) {
             if (h->avctx->colorspace == AVCOL_SPC_RGB) {

                 *fmt++ = AV_PIX_FMT_GBRP10;

             } else

                 *fmt++ = AV_PIX_FMT_YUV444P10;

         } else if (CHROMA422(h))

             *fmt++ = AV_PIX_FMT_YUV422P10;

         else

             *fmt++ = AV_PIX_FMT_YUV420P10;

         break;

     case 12:

         if (CHROMA444(h)) {
             if (h->avctx->colorspace == AVCOL_SPC_RGB) {

                 *fmt++ = AV_PIX_FMT_GBRP12;

             } else

                 *fmt++ = AV_PIX_FMT_YUV444P12;

         } else if (CHROMA422(h))

             *fmt++ = AV_PIX_FMT_YUV422P12;

         else

             *fmt++ = AV_PIX_FMT_YUV420P12;

         break;
     case 14:
         if (CHROMA444(h)) {
             if (h->avctx->colorspace == AVCOL_SPC_RGB) {

                 *fmt++ = AV_PIX_FMT_GBRP14;

             } else

                 *fmt++ = AV_PIX_FMT_YUV444P14;

         } else if (CHROMA422(h))

             *fmt++ = AV_PIX_FMT_YUV422P14;

         else

             *fmt++ = AV_PIX_FMT_YUV420P14;

         break;
     case 8:

 #if CONFIG_H264_VDPAU_HWACCEL
         *fmt++ = AV_PIX_FMT_VDPAU;
 #endif

         if (CHROMA444(h)) {

             if (h->avctx->colorspace == AVCOL_SPC_RGB)

                 *fmt++ = AV_PIX_FMT_GBRP;

             else if (h->avctx->color_range == AVCOL_RANGE_JPEG)

                 *fmt++ = AV_PIX_FMT_YUVJ444P;

             else

                 *fmt++ = AV_PIX_FMT_YUV444P;

         } else if (CHROMA422(h)) {

             if (h->avctx->color_range == AVCOL_RANGE_JPEG)

                 *fmt++ = AV_PIX_FMT_YUVJ422P;

             else

                 *fmt++ = AV_PIX_FMT_YUV422P;

         } else {

 #if CONFIG_H264_DXVA2_HWACCEL
             *fmt++ = AV_PIX_FMT_DXVA2_VLD;
 #endif

 #if CONFIG_H264_D3D11VA_HWACCEL
             *fmt++ = AV_PIX_FMT_D3D11VA_VLD;
 #endif

 #if CONFIG_H264_VAAPI_HWACCEL

             *fmt++ = AV_PIX_FMT_VAAPI;

 #endif
 #if CONFIG_H264_VDA_HWACCEL
             *fmt++ = AV_PIX_FMT_VDA_VLD;
             *fmt++ = AV_PIX_FMT_VDA;
 #endif

 #if CONFIG_H264_VIDEOTOOLBOX_HWACCEL
             *fmt++ = AV_PIX_FMT_VIDEOTOOLBOX;
 #endif

             if (h->avctx->codec->pix_fmts)
                 choices = h->avctx->codec->pix_fmts;
             else if (h->avctx->color_range == AVCOL_RANGE_JPEG)

                 *fmt++ = AV_PIX_FMT_YUVJ420P;

             else

                 *fmt++ = AV_PIX_FMT_YUV420P;

         }
         break;
     default:
         av_log(h->avctx, AV_LOG_ERROR,

                "Unsupported bit depth %d\n", h->ps.sps->bit_depth_luma);

         return AVERROR_INVALIDDATA;
     }

     *fmt = AV_PIX_FMT_NONE;
 

     for (i=0; choices[i] != AV_PIX_FMT_NONE; i++)
         if (choices[i] == h->avctx->pix_fmt && !force_callback)
             return choices[i];
     return ff_thread_get_format(h->avctx, choices);

 }
 
 /* export coded and cropped frame dimensions to AVCodecContext */
 static int init_dimensions(H264Context *h)
 {

     const SPS *sps = (const SPS*)h->ps.sps;

     int width  = h->width  - (sps->crop_right + sps->crop_left);
     int height = h->height - (sps->crop_top   + sps->crop_bottom);

     av_assert0(sps->crop_right + sps->crop_left < (unsigned)h->width);
     av_assert0(sps->crop_top + sps->crop_bottom < (unsigned)h->height);

 
     /* handle container cropping */

     if (FFALIGN(h->avctx->width,  16) == FFALIGN(width,  16) &&

         FFALIGN(h->avctx->height, 16) == FFALIGN(height, 16) &&
         h->avctx->width  <= width &&
         h->avctx->height <= height
     ) {

         width  = h->avctx->width;
         height = h->avctx->height;
     }
 
     h->avctx->coded_width  = h->width;
     h->avctx->coded_height = h->height;
     h->avctx->width        = width;
     h->avctx->height       = height;
 
     return 0;
 }
 

 static int h264_slice_header_init(H264Context *h)

 {

     const SPS *sps = h->ps.sps;

     int i, ret;
 

     ff_set_sar(h->avctx, sps->sar);

     av_pix_fmt_get_chroma_sub_sample(h->avctx->pix_fmt,
                                      &h->chroma_x_shift, &h->chroma_y_shift);
 

     if (sps->timing_info_present_flag) {
         int64_t den = sps->time_scale;

         if (h->sei.unregistered.x264_build < 44U)

             den *= 2;

         av_reduce(&h->avctx->framerate.den, &h->avctx->framerate.num,

                   sps->num_units_in_tick * h->avctx->ticks_per_frame, den, 1 << 30);

     }
 

     ff_h264_free_tables(h);
 

     h->first_field           = 0;
     h->prev_interlaced_frame = 1;
 
     init_scan_tables(h);
     ret = ff_h264_alloc_tables(h);
     if (ret < 0) {
         av_log(h->avctx, AV_LOG_ERROR, "Could not allocate memory\n");

         goto fail;

     }
 

 #if FF_API_CAP_VDPAU

     if (h->avctx->codec &&

         h->avctx->codec->capabilities & AV_CODEC_CAP_HWACCEL_VDPAU &&

         (sps->bit_depth_luma != 8 || sps->chroma_format_idc > 1)) {

         av_log(h->avctx, AV_LOG_ERROR,
                 "VDPAU decoding does not support video colorspace.\n");
         ret = AVERROR_INVALIDDATA;
         goto fail;

     }

 #endif

     if (sps->bit_depth_luma < 8 || sps->bit_depth_luma > 14 ||
         sps->bit_depth_luma == 11 || sps->bit_depth_luma == 13

     ) {

         av_log(h->avctx, AV_LOG_ERROR, "Unsupported bit depth %d\n",

                sps->bit_depth_luma);

         ret = AVERROR_INVALIDDATA;
         goto fail;

     }
 

     h->cur_bit_depth_luma         =

     h->avctx->bits_per_raw_sample = sps->bit_depth_luma;

     h->cur_chroma_format_idc      = sps->chroma_format_idc;

     h->pixel_shift                = sps->bit_depth_luma > 8;
     h->chroma_format_idc          = sps->chroma_format_idc;
     h->bit_depth_luma             = sps->bit_depth_luma;

     ff_h264dsp_init(&h->h264dsp, sps->bit_depth_luma,
                     sps->chroma_format_idc);
     ff_h264chroma_init(&h->h264chroma, sps->bit_depth_chroma);
     ff_h264qpel_init(&h->h264qpel, sps->bit_depth_luma);
     ff_h264_pred_init(&h->hpc, h->avctx->codec_id, sps->bit_depth_luma,
                       sps->chroma_format_idc);
     ff_videodsp_init(&h->vdsp, sps->bit_depth_luma);

     if (!HAVE_THREADS || !(h->avctx->active_thread_type & FF_THREAD_SLICE)) {

         ret = ff_h264_slice_context_init(h, &h->slice_ctx[0]);

         if (ret < 0) {
             av_log(h->avctx, AV_LOG_ERROR, "context_init() failed.\n");

             goto fail;

         }
     } else {

         for (i = 0; i < h->nb_slice_ctx; i++) {

             H264SliceContext *sl = &h->slice_ctx[i];

             sl->h264               = h;
             sl->intra4x4_pred_mode = h->intra4x4_pred_mode + i * 8 * 2 * h->mb_stride;
             sl->mvd_table[0]       = h->mvd_table[0]       + i * 8 * 2 * h->mb_stride;
             sl->mvd_table[1]       = h->mvd_table[1]       + i * 8 * 2 * h->mb_stride;

             if ((ret = ff_h264_slice_context_init(h, sl)) < 0) {

                 av_log(h->avctx, AV_LOG_ERROR, "context_init() failed.\n");

                 goto fail;

             }

         }

     }
 
     h->context_initialized = 1;
 
     return 0;

 fail:

     ff_h264_free_tables(h);

     h->context_initialized = 0;
     return ret;

 }
 

 static enum AVPixelFormat non_j_pixfmt(enum AVPixelFormat a)
 {
     switch (a) {
     case AV_PIX_FMT_YUVJ420P: return AV_PIX_FMT_YUV420P;
     case AV_PIX_FMT_YUVJ422P: return AV_PIX_FMT_YUV422P;
     case AV_PIX_FMT_YUVJ444P: return AV_PIX_FMT_YUV444P;
     default:
         return a;
     }
 }
 

 static int h264_init_ps(H264Context *h, const H264SliceContext *sl, int first_slice)

 {
     const SPS *sps;

     int needs_reinit = 0, must_reinit, ret;
 
     if (first_slice) {
         av_buffer_unref(&h->ps.pps_ref);
         h->ps.pps = NULL;
         h->ps.pps_ref = av_buffer_ref(h->ps.pps_list[sl->pps_id]);
         if (!h->ps.pps_ref)
             return AVERROR(ENOMEM);
         h->ps.pps = (const PPS*)h->ps.pps_ref->data;
     }

 
     if (h->ps.sps != (const SPS*)h->ps.sps_list[h->ps.pps->sps_id]->data) {

         av_buffer_unref(&h->ps.sps_ref);
         h->ps.sps = NULL;
         h->ps.sps_ref = av_buffer_ref(h->ps.sps_list[h->ps.pps->sps_id]);
         if (!h->ps.sps_ref)
             return AVERROR(ENOMEM);
         h->ps.sps = (const SPS*)h->ps.sps_ref->data;
 
         if (h->mb_width  != h->ps.sps->mb_width ||
             h->mb_height != h->ps.sps->mb_height * (2 - h->ps.sps->frame_mbs_only_flag) ||
             h->cur_bit_depth_luma    != h->ps.sps->bit_depth_luma ||
             h->cur_chroma_format_idc != h->ps.sps->chroma_format_idc
         )
             needs_reinit = 1;

 
         if (h->bit_depth_luma    != h->ps.sps->bit_depth_luma ||
             h->chroma_format_idc != h->ps.sps->chroma_format_idc)
             needs_reinit         = 1;
     }
     sps = h->ps.sps;
 

     must_reinit = (h->context_initialized &&
                     (   16*sps->mb_width != h->avctx->coded_width
                      || 16*sps->mb_height * (2 - sps->frame_mbs_only_flag) != h->avctx->coded_height
                      || h->cur_bit_depth_luma    != sps->bit_depth_luma
                      || h->cur_chroma_format_idc != sps->chroma_format_idc
                      || h->mb_width  != sps->mb_width
                      || h->mb_height != sps->mb_height * (2 - sps->frame_mbs_only_flag)
                     ));
     if (h->avctx->pix_fmt == AV_PIX_FMT_NONE
         || (non_j_pixfmt(h->avctx->pix_fmt) != non_j_pixfmt(get_pixel_format(h, 0))))
         must_reinit = 1;
 
     if (first_slice && av_cmp_q(sps->sar, h->avctx->sample_aspect_ratio))
         must_reinit = 1;

     if (!h->setup_finished) {
         h->avctx->profile = ff_h264_get_profile(sps);
         h->avctx->level   = sps->level_idc;
         h->avctx->refs    = sps->ref_frame_count;

         h->mb_width  = sps->mb_width;
         h->mb_height = sps->mb_height * (2 - sps->frame_mbs_only_flag);
         h->mb_num    = h->mb_width * h->mb_height;
         h->mb_stride = h->mb_width + 1;

         h->b_stride = h->mb_width * 4;

         h->chroma_y_shift = sps->chroma_format_idc <= 1; // 400 uses yuv420p

         h->width  = 16 * h->mb_width;
         h->height = 16 * h->mb_height;

         ret = init_dimensions(h);
         if (ret < 0)
             return ret;

         if (sps->video_signal_type_present_flag) {
             h->avctx->color_range = sps->full_range > 0 ? AVCOL_RANGE_JPEG
                                                         : AVCOL_RANGE_MPEG;
             if (sps->colour_description_present_flag) {
                 if (h->avctx->colorspace != sps->colorspace)
                     needs_reinit = 1;
                 h->avctx->color_primaries = sps->color_primaries;
                 h->avctx->color_trc       = sps->color_trc;
                 h->avctx->colorspace      = sps->colorspace;
             }

         }
     }
 

     if (!h->context_initialized || must_reinit || needs_reinit) {
         int flush_changes = h->context_initialized;

         h->context_initialized = 0;
         if (sl != h->slice_ctx) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "changing width %d -> %d / height %d -> %d on "
                    "slice %d\n",
                    h->width, h->avctx->coded_width,
                    h->height, h->avctx->coded_height,
                    h->current_slice + 1);
             return AVERROR_INVALIDDATA;
         }
 

         av_assert1(first_slice);
 
         if (flush_changes)
             ff_h264_flush_change(h);

         if ((ret = get_pixel_format(h, 1)) < 0)

             return ret;
         h->avctx->pix_fmt = ret;
 
         av_log(h->avctx, AV_LOG_VERBOSE, "Reinit context to %dx%d, "

                "pix_fmt: %s\n", h->width, h->height, av_get_pix_fmt_name(h->avctx->pix_fmt));

 
         if ((ret = h264_slice_header_init(h)) < 0) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "h264_slice_header_init() failed\n");
             return ret;
         }
     }
 
     return 0;
 }
 

 static int h264_export_frame_props(H264Context *h)
 {
     const SPS *sps = h->ps.sps;
     H264Picture *cur = h->cur_pic_ptr;
 
     cur->f->interlaced_frame = 0;
     cur->f->repeat_pict      = 0;
 
     /* Signal interlacing information externally. */
     /* Prioritize picture timing SEI information over used
      * decoding process if it exists. */
 
     if (sps->pic_struct_present_flag) {
         H264SEIPictureTiming *pt = &h->sei.picture_timing;
         switch (pt->pic_struct) {
         case SEI_PIC_STRUCT_FRAME:
             break;
         case SEI_PIC_STRUCT_TOP_FIELD:
         case SEI_PIC_STRUCT_BOTTOM_FIELD:
             cur->f->interlaced_frame = 1;
             break;
         case SEI_PIC_STRUCT_TOP_BOTTOM:
         case SEI_PIC_STRUCT_BOTTOM_TOP:
             if (FIELD_OR_MBAFF_PICTURE(h))
                 cur->f->interlaced_frame = 1;
             else
                 // try to flag soft telecine progressive
                 cur->f->interlaced_frame = h->prev_interlaced_frame;
             break;
         case SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
         case SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
             /* Signal the possibility of telecined film externally
              * (pic_struct 5,6). From these hints, let the applications
              * decide if they apply deinterlacing. */
             cur->f->repeat_pict = 1;
             break;
         case SEI_PIC_STRUCT_FRAME_DOUBLING:
             cur->f->repeat_pict = 2;
             break;
         case SEI_PIC_STRUCT_FRAME_TRIPLING:
             cur->f->repeat_pict = 4;
             break;
         }
 
         if ((pt->ct_type & 3) &&
             pt->pic_struct <= SEI_PIC_STRUCT_BOTTOM_TOP)
             cur->f->interlaced_frame = (pt->ct_type & (1 << 1)) != 0;
     } else {
         /* Derive interlacing flag from used decoding process. */
         cur->f->interlaced_frame = FIELD_OR_MBAFF_PICTURE(h);
     }
     h->prev_interlaced_frame = cur->f->interlaced_frame;
 
     if (cur->field_poc[0] != cur->field_poc[1]) {
         /* Derive top_field_first from field pocs. */
         cur->f->top_field_first = cur->field_poc[0] < cur->field_poc[1];
     } else {

         if (sps->pic_struct_present_flag) {

             /* Use picture timing SEI information. Even if it is a
              * information of a past frame, better than nothing. */
             if (h->sei.picture_timing.pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM ||
                 h->sei.picture_timing.pic_struct == SEI_PIC_STRUCT_TOP_BOTTOM_TOP)
                 cur->f->top_field_first = 1;
             else
                 cur->f->top_field_first = 0;

         } else if (cur->f->interlaced_frame) {
             /* Default to top field first when pic_struct_present_flag
              * is not set but interlaced frame detected */
             cur->f->top_field_first = 1;

         } else {
             /* Most likely progressive */
             cur->f->top_field_first = 0;
         }
     }
 
     if (h->sei.frame_packing.present &&

         h->sei.frame_packing.frame_packing_arrangement_type <= 6 &&

         h->sei.frame_packing.content_interpretation_type > 0 &&
         h->sei.frame_packing.content_interpretation_type < 3) {
         H264SEIFramePacking *fp = &h->sei.frame_packing;
         AVStereo3D *stereo = av_stereo3d_create_side_data(cur->f);

         if (stereo) {
         switch (fp->frame_packing_arrangement_type) {

         case 0:
             stereo->type = AV_STEREO3D_CHECKERBOARD;
             break;
         case 1:
             stereo->type = AV_STEREO3D_COLUMNS;
             break;
         case 2:
             stereo->type = AV_STEREO3D_LINES;
             break;
         case 3:

             if (fp->quincunx_sampling_flag)

                 stereo->type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
             else
                 stereo->type = AV_STEREO3D_SIDEBYSIDE;
             break;
         case 4:
             stereo->type = AV_STEREO3D_TOPBOTTOM;
             break;
         case 5:
             stereo->type = AV_STEREO3D_FRAMESEQUENCE;
             break;
         case 6:
             stereo->type = AV_STEREO3D_2D;
             break;
         }
 
         if (fp->content_interpretation_type == 2)
             stereo->flags = AV_STEREO3D_FLAG_INVERT;

         }

     }
 
     if (h->sei.display_orientation.present &&
         (h->sei.display_orientation.anticlockwise_rotation ||
          h->sei.display_orientation.hflip ||
          h->sei.display_orientation.vflip)) {
         H264SEIDisplayOrientation *o = &h->sei.display_orientation;
         double angle = o->anticlockwise_rotation * 360 / (double) (1 << 16);
         AVFrameSideData *rotation = av_frame_new_side_data(cur->f,
                                                            AV_FRAME_DATA_DISPLAYMATRIX,
                                                            sizeof(int32_t) * 9);

         if (rotation) {
             av_display_rotation_set((int32_t *)rotation->data, angle);
             av_display_matrix_flip((int32_t *)rotation->data,
                                    o->hflip, o->vflip);
         }

     }
 
     if (h->sei.afd.present) {
         AVFrameSideData *sd = av_frame_new_side_data(cur->f, AV_FRAME_DATA_AFD,
                                                      sizeof(uint8_t));
 

         if (sd) {
             *sd->data = h->sei.afd.active_format_description;
             h->sei.afd.present = 0;
         }

     }
 
     if (h->sei.a53_caption.a53_caption) {
         H264SEIA53Caption *a53 = &h->sei.a53_caption;
         AVFrameSideData *sd = av_frame_new_side_data(cur->f,
                                                      AV_FRAME_DATA_A53_CC,
                                                      a53->a53_caption_size);

         if (sd)
             memcpy(sd->data, a53->a53_caption, a53->a53_caption_size);

         av_freep(&a53->a53_caption);
         a53->a53_caption_size = 0;

         h->avctx->properties |= FF_CODEC_PROPERTY_CLOSED_CAPTIONS;

     }
 
     return 0;
 }
 

 /* This function is called right after decoding the slice header for a first
  * slice in a field (or a frame). It decides whether we are decoding a new frame
  * or a second field in a pair and does the necessary setup.
  */

 static int h264_field_start(H264Context *h, const H264SliceContext *sl,

                             const H2645NAL *nal, int first_slice)

 {

     int i;

     const SPS *sps;

 
     int last_pic_structure, last_pic_droppable, ret;
 

     ret = h264_init_ps(h, sl, first_slice);
     if (ret < 0)
         return ret;
 

     sps = h->ps.sps;
 

     last_pic_droppable   = h->droppable;
     last_pic_structure   = h->picture_structure;

     h->droppable         = (nal->ref_idc == 0);

     h->picture_structure = sl->picture_structure;
 

     h->poc.frame_num        = sl->frame_num;
     h->poc.poc_lsb          = sl->poc_lsb;
     h->poc.delta_poc_bottom = sl->delta_poc_bottom;
     h->poc.delta_poc[0]     = sl->delta_poc[0];
     h->poc.delta_poc[1]     = sl->delta_poc[1];
 

     /* Shorten frame num gaps so we don't have to allocate reference
      * frames just to throw them away */
     if (h->poc.frame_num != h->poc.prev_frame_num) {
         int unwrap_prev_frame_num = h->poc.prev_frame_num;
         int max_frame_num         = 1 << sps->log2_max_frame_num;
 
         if (unwrap_prev_frame_num > h->poc.frame_num)
             unwrap_prev_frame_num -= max_frame_num;
 
         if ((h->poc.frame_num - unwrap_prev_frame_num) > sps->ref_frame_count) {
             unwrap_prev_frame_num = (h->poc.frame_num - sps->ref_frame_count) - 1;
             if (unwrap_prev_frame_num < 0)
                 unwrap_prev_frame_num += max_frame_num;
 
             h->poc.prev_frame_num = unwrap_prev_frame_num;
         }
     }
 
     /* See if we have a decoded first field looking for a pair...
      * Here, we're using that to see if we should mark previously
      * decode frames as "finished".
      * We have to do that before the "dummy" in-between frame allocation,

      * since that can modify h->cur_pic_ptr. */

     if (h->first_field) {

         av_assert0(h->cur_pic_ptr);
         av_assert0(h->cur_pic_ptr->f->buf[0]);

         assert(h->cur_pic_ptr->reference != DELAYED_PIC_REF);
 

         /* Mark old field/frame as completed */
         if (h->cur_pic_ptr->tf.owner == h->avctx) {
             ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                       last_pic_structure == PICT_BOTTOM_FIELD);
         }
 

         /* figure out if we have a complementary field pair */
         if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
             /* Previous field is unmatched. Don't display it, but let it
              * remain for reference if marked as such. */

             if (last_pic_structure != PICT_FRAME) {

                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                           last_pic_structure == PICT_TOP_FIELD);
             }
         } else {
             if (h->cur_pic_ptr->frame_num != h->poc.frame_num) {
                 /* This and previous field were reference, but had
                  * different frame_nums. Consider this field first in
                  * pair. Throw away previous field except for reference
                  * purposes. */

                 if (last_pic_structure != PICT_FRAME) {

                     ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                               last_pic_structure == PICT_TOP_FIELD);
                 }
             } else {
                 /* Second field in complementary pair */
                 if (!((last_pic_structure   == PICT_TOP_FIELD &&
                        h->picture_structure == PICT_BOTTOM_FIELD) ||
                       (last_pic_structure   == PICT_BOTTOM_FIELD &&
                        h->picture_structure == PICT_TOP_FIELD))) {
                     av_log(h->avctx, AV_LOG_ERROR,
                            "Invalid field mode combination %d/%d\n",
                            last_pic_structure, h->picture_structure);
                     h->picture_structure = last_pic_structure;
                     h->droppable         = last_pic_droppable;
                     return AVERROR_INVALIDDATA;
                 } else if (last_pic_droppable != h->droppable) {
                     avpriv_request_sample(h->avctx,
                                           "Found reference and non-reference fields in the same frame, which");
                     h->picture_structure = last_pic_structure;
                     h->droppable         = last_pic_droppable;
                     return AVERROR_PATCHWELCOME;
                 }
             }
         }
     }
 

     while (h->poc.frame_num != h->poc.prev_frame_num && !h->first_field &&

            h->poc.frame_num != (h->poc.prev_frame_num + 1) % (1 << sps->log2_max_frame_num)) {
         H264Picture *prev = h->short_ref_count ? h->short_ref[0] : NULL;
         av_log(h->avctx, AV_LOG_DEBUG, "Frame num gap %d %d\n",
                h->poc.frame_num, h->poc.prev_frame_num);

         if (!sps->gaps_in_frame_num_allowed_flag)
             for(i=0; i<FF_ARRAY_ELEMS(h->last_pocs); i++)
                 h->last_pocs[i] = INT_MIN;
         ret = h264_frame_start(h);

         if (ret < 0) {
             h->first_field = 0;
             return ret;
         }
 
         h->poc.prev_frame_num++;
         h->poc.prev_frame_num        %= 1 << sps->log2_max_frame_num;
         h->cur_pic_ptr->frame_num = h->poc.prev_frame_num;

         h->cur_pic_ptr->invalid_gap = !sps->gaps_in_frame_num_allowed_flag;

         ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 0);
         ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 1);
 
         h->explicit_ref_marking = 0;
         ret = ff_h264_execute_ref_pic_marking(h);
         if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
             return ret;
         /* Error concealment: If a ref is missing, copy the previous ref
          * in its place.
          * FIXME: Avoiding a memcpy would be nice, but ref handling makes
          * many assumptions about there being no actual duplicates.
          * FIXME: This does not copy padding for out-of-frame motion
          * vectors.  Given we are concealing a lost frame, this probably
          * is not noticeable by comparison, but it should be fixed. */
         if (h->short_ref_count) {
             if (prev &&
                 h->short_ref[0]->f->width == prev->f->width &&
                 h->short_ref[0]->f->height == prev->f->height &&
                 h->short_ref[0]->f->format == prev->f->format) {
                 av_image_copy(h->short_ref[0]->f->data,
                               h->short_ref[0]->f->linesize,
                               (const uint8_t **)prev->f->data,
                               prev->f->linesize,
                               prev->f->format,

                               prev->f->width,
                               prev->f->height);

                 h->short_ref[0]->poc = prev->poc + 2;
             }
             h->short_ref[0]->frame_num = h->poc.prev_frame_num;
         }
     }
 
     /* See if we have a decoded first field looking for a pair...
      * We're using that to see whether to continue decoding in that
      * frame, or to allocate a new one. */
     if (h->first_field) {

         av_assert0(h->cur_pic_ptr);
         av_assert0(h->cur_pic_ptr->f->buf[0]);

         assert(h->cur_pic_ptr->reference != DELAYED_PIC_REF);
 
         /* figure out if we have a complementary field pair */
         if (!FIELD_PICTURE(h) || h->picture_structure == last_pic_structure) {
             /* Previous field is unmatched. Don't display it, but let it
              * remain for reference if marked as such. */

             h->missing_fields ++;

             h->cur_pic_ptr = NULL;
             h->first_field = FIELD_PICTURE(h);
         } else {

             h->missing_fields = 0;

             if (h->cur_pic_ptr->frame_num != h->poc.frame_num) {

                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                           h->picture_structure==PICT_BOTTOM_FIELD);

                 /* This and the previous field had different frame_nums.
                  * Consider this field first in pair. Throw away previous
                  * one except for reference purposes. */
                 h->first_field = 1;
                 h->cur_pic_ptr = NULL;

             } else if (h->cur_pic_ptr->reference & DELAYED_PIC_REF) {
                 /* This frame was already output, we cannot draw into it
                  * anymore.
                  */
                 h->first_field = 1;
                 h->cur_pic_ptr = NULL;

             } else {
                 /* Second field in complementary pair */
                 h->first_field = 0;
             }
         }
     } else {
         /* Frame or first field in a potentially complementary pair */
         h->first_field = FIELD_PICTURE(h);
     }
 
     if (!FIELD_PICTURE(h) || h->first_field) {
         if (h264_frame_start(h) < 0) {
             h->first_field = 0;
             return AVERROR_INVALIDDATA;
         }
     } else {
         release_unused_pictures(h, 0);
     }

     /* Some macroblocks can be accessed before they're available in case
     * of lost slices, MBAFF or threading. */
     if (FIELD_PICTURE(h)) {
         for(i = (h->picture_structure == PICT_BOTTOM_FIELD); i<h->mb_height; i++)
             memset(h->slice_table + i*h->mb_stride, -1, (h->mb_stride - (i+1==h->mb_height)) * sizeof(*h->slice_table));
     } else {
         memset(h->slice_table, -1,
             (h->mb_height * h->mb_stride - 1) * sizeof(*h->slice_table));
     }

     ff_h264_init_poc(h->cur_pic_ptr->field_poc, &h->cur_pic_ptr->poc,
                      h->ps.sps, &h->poc, h->picture_structure, nal->ref_idc);
 
     memcpy(h->mmco, sl->mmco, sl->nb_mmco * sizeof(*h->mmco));
     h->nb_mmco = sl->nb_mmco;
     h->explicit_ref_marking = sl->explicit_ref_marking;
 

     h->picture_idr = nal->type == H264_NAL_IDR_SLICE;
 

     if (h->sei.recovery_point.recovery_frame_cnt >= 0) {
         const int sei_recovery_frame_cnt = h->sei.recovery_point.recovery_frame_cnt;
 
         if (h->poc.frame_num != sei_recovery_frame_cnt || sl->slice_type_nos != AV_PICTURE_TYPE_I)
             h->valid_recovery_point = 1;
 
         if (   h->recovery_frame < 0
             || av_mod_uintp2(h->recovery_frame - h->poc.frame_num, h->ps.sps->log2_max_frame_num) > sei_recovery_frame_cnt) {
             h->recovery_frame = av_mod_uintp2(h->poc.frame_num + sei_recovery_frame_cnt, h->ps.sps->log2_max_frame_num);
 
             if (!h->valid_recovery_point)
                 h->recovery_frame = h->poc.frame_num;
         }

     }
 

     h->cur_pic_ptr->f->key_frame |= (nal->type == H264_NAL_IDR_SLICE);

     if (nal->type == H264_NAL_IDR_SLICE ||
         (h->recovery_frame == h->poc.frame_num && nal->ref_idc)) {

         h->recovery_frame         = -1;
         h->cur_pic_ptr->recovered = 1;
     }
     // If we have an IDR, all frames after it in decoded order are
     // "recovered".
     if (nal->type == H264_NAL_IDR_SLICE)
         h->frame_recovered |= FRAME_RECOVERED_IDR;

 #if 1
     h->cur_pic_ptr->recovered |= h->frame_recovered;
 #else

     h->cur_pic_ptr->recovered |= !!(h->frame_recovered & FRAME_RECOVERED_IDR);

 #endif

     /* Set the frame properties/side data. Only done for the second field in
      * field coded frames, since some SEI information is present for each field
      * and is merged by the SEI parsing code. */
     if (!FIELD_PICTURE(h) || !h->first_field) {
         ret = h264_export_frame_props(h);
         if (ret < 0)
             return ret;
     }
 

     return 0;
 }
 

 static int h264_slice_header_parse(const H264Context *h, H264SliceContext *sl,

                                    const H2645NAL *nal)

 {

     const SPS *sps;
     const PPS *pps;

     int ret;

     unsigned int slice_type, tmp, i;

     int field_pic_flag, bottom_field_flag;

     int first_slice = sl == h->slice_ctx && !h->current_slice;

     int picture_structure;

     if (first_slice)
         av_assert0(!h->setup_finished);
 

     sl->first_mb_addr = get_ue_golomb_long(&sl->gb);

     slice_type = get_ue_golomb_31(&sl->gb);

     if (slice_type > 9) {
         av_log(h->avctx, AV_LOG_ERROR,

                "slice type %d too large at %d\n",

                slice_type, sl->first_mb_addr);

         return AVERROR_INVALIDDATA;
     }
     if (slice_type > 4) {
         slice_type -= 5;

         sl->slice_type_fixed = 1;

     } else

         sl->slice_type_fixed = 0;

     slice_type         = ff_h264_golomb_to_pict_type[slice_type];

     sl->slice_type     = slice_type;
     sl->slice_type_nos = slice_type & 3;

     if (nal->type  == H264_NAL_IDR_SLICE &&

         sl->slice_type_nos != AV_PICTURE_TYPE_I) {

         av_log(h->avctx, AV_LOG_ERROR, "A non-intra slice in an IDR NAL unit.\n");
         return AVERROR_INVALIDDATA;
     }
 

     sl->pps_id = get_ue_golomb(&sl->gb);
     if (sl->pps_id >= MAX_PPS_COUNT) {
         av_log(h->avctx, AV_LOG_ERROR, "pps_id %u out of range\n", sl->pps_id);

         return AVERROR_INVALIDDATA;
     }

     if (!h->ps.pps_list[sl->pps_id]) {

         av_log(h->avctx, AV_LOG_ERROR,
                "non-existing PPS %u referenced\n",

                sl->pps_id);

         return AVERROR_INVALIDDATA;
     }

     pps = (const PPS*)h->ps.pps_list[sl->pps_id]->data;

     if (!h->ps.sps_list[pps->sps_id]) {

         av_log(h->avctx, AV_LOG_ERROR,

                "non-existing SPS %u referenced\n", pps->sps_id);

         return AVERROR_INVALIDDATA;
     }

     sps = (const SPS*)h->ps.sps_list[pps->sps_id]->data;

     sl->frame_num = get_bits(&sl->gb, sps->log2_max_frame_num);

     if (!first_slice) {

         if (h->poc.frame_num != sl->frame_num) {

             av_log(h->avctx, AV_LOG_ERROR, "Frame num change from %d to %d\n",

                    h->poc.frame_num, sl->frame_num);

             return AVERROR_INVALIDDATA;
         }
     }

     sl->mb_mbaff       = 0;

     if (sps->frame_mbs_only_flag) {

         picture_structure = PICT_FRAME;

     } else {

         if (!sps->direct_8x8_inference_flag && slice_type == AV_PICTURE_TYPE_B) {

             av_log(h->avctx, AV_LOG_ERROR, "This stream was generated by a broken encoder, invalid 8x8 inference\n");
             return -1;
         }

         field_pic_flag = get_bits1(&sl->gb);

         if (field_pic_flag) {

             bottom_field_flag = get_bits1(&sl->gb);

             picture_structure = PICT_TOP_FIELD + bottom_field_flag;

         } else {

             picture_structure = PICT_FRAME;

         }

     }

     sl->picture_structure      = picture_structure;

     sl->mb_field_decoding_flag = picture_structure != PICT_FRAME;

     if (picture_structure == PICT_FRAME) {

         sl->curr_pic_num = sl->frame_num;
         sl->max_pic_num  = 1 << sps->log2_max_frame_num;

     } else {

         sl->curr_pic_num = 2 * sl->frame_num + 1;
         sl->max_pic_num  = 1 << (sps->log2_max_frame_num + 1);

     }
 

     if (nal->type == H264_NAL_IDR_SLICE)

         get_ue_golomb_long(&sl->gb); /* idr_pic_id */

     if (sps->poc_type == 0) {

         sl->poc_lsb = get_bits(&sl->gb, sps->log2_max_poc_lsb);

         if (pps->pic_order_present == 1 && picture_structure == PICT_FRAME)
             sl->delta_poc_bottom = get_se_golomb(&sl->gb);

     }
 

     if (sps->poc_type == 1 && !sps->delta_pic_order_always_zero_flag) {

         sl->delta_poc[0] = get_se_golomb(&sl->gb);

         if (pps->pic_order_present == 1 && picture_structure == PICT_FRAME)
             sl->delta_poc[1] = get_se_golomb(&sl->gb);

     }
 

     sl->redundant_pic_count = 0;

     if (pps->redundant_pic_cnt_present)

         sl->redundant_pic_count = get_ue_golomb(&sl->gb);

     if (sl->slice_type_nos == AV_PICTURE_TYPE_B)
         sl->direct_spatial_mv_pred = get_bits1(&sl->gb);
 

     ret = ff_h264_parse_ref_count(&sl->list_count, sl->ref_count,

                                   &sl->gb, pps, sl->slice_type_nos,

                                   picture_structure, h->avctx);

     if (ret < 0)
         return ret;
 

     if (sl->slice_type_nos != AV_PICTURE_TYPE_I) {

        ret = ff_h264_decode_ref_pic_list_reordering(sl, h->avctx);

        if (ret < 0) {

            sl->ref_count[1] = sl->ref_count[0] = 0;

            return ret;
        }
     }
 

     sl->pwt.use_weight = 0;
     for (i = 0; i < 2; i++) {
         sl->pwt.luma_weight_flag[i]   = 0;
         sl->pwt.chroma_weight_flag[i] = 0;
     }

     if ((pps->weighted_pred && sl->slice_type_nos == AV_PICTURE_TYPE_P) ||
         (pps->weighted_bipred_idc == 1 &&

          sl->slice_type_nos == AV_PICTURE_TYPE_B)) {
         ret = ff_h264_pred_weight_table(&sl->gb, sps, sl->ref_count,

                                   sl->slice_type_nos, &sl->pwt,
                                   picture_structure, h->avctx);

         if (ret < 0)
             return ret;
     }

     sl->explicit_ref_marking = 0;

     if (nal->ref_idc) {

         ret = ff_h264_decode_ref_pic_marking(sl, &sl->gb, nal, h->avctx);

         if (ret < 0 && (h->avctx->err_recognition & AV_EF_EXPLODE))
             return AVERROR_INVALIDDATA;
     }
 

     if (sl->slice_type_nos != AV_PICTURE_TYPE_I && pps->cabac) {

         tmp = get_ue_golomb_31(&sl->gb);

         if (tmp > 2) {
             av_log(h->avctx, AV_LOG_ERROR, "cabac_init_idc %u overflow\n", tmp);
             return AVERROR_INVALIDDATA;
         }

         sl->cabac_init_idc = tmp;

     }
 

     sl->last_qscale_diff = 0;

     tmp = pps->init_qp + (unsigned)get_se_golomb(&sl->gb);

     if (tmp > 51 + 6 * (sps->bit_depth_luma - 8)) {

         av_log(h->avctx, AV_LOG_ERROR, "QP %u out of range\n", tmp);
         return AVERROR_INVALIDDATA;
     }

     sl->qscale       = tmp;

     sl->chroma_qp[0] = get_chroma_qp(pps, 0, sl->qscale);
     sl->chroma_qp[1] = get_chroma_qp(pps, 1, sl->qscale);

     // FIXME qscale / qp ... stuff

     if (sl->slice_type == AV_PICTURE_TYPE_SP)

         get_bits1(&sl->gb); /* sp_for_switch_flag */

     if (sl->slice_type == AV_PICTURE_TYPE_SP ||
         sl->slice_type == AV_PICTURE_TYPE_SI)

         get_se_golomb(&sl->gb); /* slice_qs_delta */

     sl->deblocking_filter     = 1;
     sl->slice_alpha_c0_offset = 0;
     sl->slice_beta_offset     = 0;

     if (pps->deblocking_filter_parameters_present) {

         tmp = get_ue_golomb_31(&sl->gb);

         if (tmp > 2) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "deblocking_filter_idc %u out of range\n", tmp);
             return AVERROR_INVALIDDATA;
         }

         sl->deblocking_filter = tmp;
         if (sl->deblocking_filter < 2)
             sl->deblocking_filter ^= 1;  // 1<->0
 
         if (sl->deblocking_filter) {

             int slice_alpha_c0_offset_div2 = get_se_golomb(&sl->gb);
             int slice_beta_offset_div2     = get_se_golomb(&sl->gb);
             if (slice_alpha_c0_offset_div2 >  6 ||
                 slice_alpha_c0_offset_div2 < -6 ||
                 slice_beta_offset_div2 >  6     ||
                 slice_beta_offset_div2 < -6) {

                 av_log(h->avctx, AV_LOG_ERROR,
                        "deblocking filter parameters %d %d out of range\n",

                        slice_alpha_c0_offset_div2, slice_beta_offset_div2);

                 return AVERROR_INVALIDDATA;
             }

             sl->slice_alpha_c0_offset = slice_alpha_c0_offset_div2 * 2;
             sl->slice_beta_offset     = slice_beta_offset_div2 * 2;

         }
     }
 

     return 0;
 }
 
 /**
  * Decode a slice header.
  * This will (re)initialize the decoder and call h264_frame_start() as needed.
  *
  * @param h h264context
  *
  * @return 0 if okay, <0 if an error occurred
  */

 int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl,
                                 const H2645NAL *nal)

 {
     int i, j, ret = 0;

     int first_slice = sl == h->slice_ctx && !h->current_slice;

     ret = h264_slice_header_parse(h, sl, nal);

     if (ret < 0)
         return ret;
 

     // discard redundant pictures

     if (sl->redundant_pic_count > 0) {
         sl->ref_count[0] = sl->ref_count[1] = 0;

         return 0;

     }

     if (sl->first_mb_addr == 0 || !h->current_slice) {
         if (h->setup_finished) {
             av_log(h->avctx, AV_LOG_ERROR, "Too many fields\n");
             return AVERROR_INVALIDDATA;
         }
     }
 

     if (sl->first_mb_addr == 0) { // FIXME better field boundary detection

         if (h->current_slice) {
             if (h->max_contexts > 1) {
                 if (!h->single_decode_warning) {
                     av_log(h->avctx, AV_LOG_WARNING, "Cannot decode multiple access units as slice threads\n");
                     h->single_decode_warning = 1;
                 }
                 h->max_contexts = 1;
                 return SLICE_SINGLETHREAD;
             }
 
             if (h->cur_pic_ptr && FIELD_PICTURE(h) && h->first_field) {
                 ret = ff_h264_field_end(h, h->slice_ctx, 1);
                 h->current_slice = 0;
                 if (ret < 0)
                     return ret;

             } else if (h->cur_pic_ptr && !FIELD_PICTURE(h) && !h->first_field && h->nal_unit_type  == H264_NAL_IDR_SLICE) {

                 av_log(h, AV_LOG_WARNING, "Broken frame packetizing\n");
                 ret = ff_h264_field_end(h, h->slice_ctx, 1);
                 h->current_slice = 0;
                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 0);
                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX, 1);
                 h->cur_pic_ptr = NULL;
                 if (ret < 0)
                     return ret;
             } else
                 return AVERROR_INVALIDDATA;

         }
 
         if (!h->first_field) {
             if (h->cur_pic_ptr && !h->droppable) {
                 ff_thread_report_progress(&h->cur_pic_ptr->tf, INT_MAX,
                                           h->picture_structure == PICT_BOTTOM_FIELD);
             }
             h->cur_pic_ptr = NULL;
         }
     }
 

     if (!h->current_slice)
         av_assert0(sl == h->slice_ctx);
 
     if (h->current_slice == 0 && !h->first_field) {
         if (
             (h->avctx->skip_frame >= AVDISCARD_NONREF && !h->nal_ref_idc) ||
             (h->avctx->skip_frame >= AVDISCARD_BIDIR  && sl->slice_type_nos == AV_PICTURE_TYPE_B) ||
             (h->avctx->skip_frame >= AVDISCARD_NONINTRA && sl->slice_type_nos != AV_PICTURE_TYPE_I) ||

             (h->avctx->skip_frame >= AVDISCARD_NONKEY && h->nal_unit_type != H264_NAL_IDR_SLICE && h->sei.recovery_point.recovery_frame_cnt < 0) ||

             h->avctx->skip_frame >= AVDISCARD_ALL) {
             return SLICE_SKIPED;
         }
     }
 
     if (!first_slice) {
         const PPS *pps = (const PPS*)h->ps.pps_list[sl->pps_id]->data;
 
         if (h->ps.pps->sps_id != pps->sps_id ||
             h->ps.pps->transform_8x8_mode != pps->transform_8x8_mode /*||
             (h->setup_finished && h->ps.pps != pps)*/) {

             av_log(h->avctx, AV_LOG_ERROR, "PPS changed between slices\n");
             return AVERROR_INVALIDDATA;
         }

         if (h->ps.sps != (const SPS*)h->ps.sps_list[h->ps.pps->sps_id]->data) {
             av_log(h->avctx, AV_LOG_ERROR,
                "SPS changed in the middle of the frame\n");
             return AVERROR_INVALIDDATA;
         }
     }

     if (h->current_slice == 0) {

         ret = h264_field_start(h, sl, nal, first_slice);

         if (ret < 0)
             return ret;

     } else {

         if (h->picture_structure != sl->picture_structure ||
             h->droppable         != (nal->ref_idc == 0)) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "Changing field mode (%d -> %d) between slices is not allowed\n",
                    h->picture_structure, sl->picture_structure);
             return AVERROR_INVALIDDATA;
         } else if (!h->cur_pic_ptr) {
             av_log(h->avctx, AV_LOG_ERROR,
                    "unset cur_pic_ptr on slice %d\n",
                    h->current_slice + 1);
             return AVERROR_INVALIDDATA;
         }

     }
 

     if (h->picture_idr && nal->type != H264_NAL_IDR_SLICE) {
         av_log(h->avctx, AV_LOG_ERROR, "Invalid mix of IDR and non-IDR slices\n");
         return AVERROR_INVALIDDATA;
     }
 

     av_assert1(h->mb_num == h->mb_width * h->mb_height);

     if (sl->first_mb_addr << FIELD_OR_MBAFF_PICTURE(h) >= h->mb_num ||
         sl->first_mb_addr >= h->mb_num) {
         av_log(h->avctx, AV_LOG_ERROR, "first_mb_in_slice overflow\n");
         return AVERROR_INVALIDDATA;
     }
     sl->resync_mb_x = sl->mb_x =  sl->first_mb_addr % h->mb_width;
     sl->resync_mb_y = sl->mb_y = (sl->first_mb_addr / h->mb_width) <<
                                  FIELD_OR_MBAFF_PICTURE(h);
     if (h->picture_structure == PICT_BOTTOM_FIELD)
         sl->resync_mb_y = sl->mb_y = sl->mb_y + 1;

     av_assert1(sl->mb_y < h->mb_height);

     ret = ff_h264_build_ref_list(h, sl);
     if (ret < 0)
         return ret;
 

     if (h->ps.pps->weighted_bipred_idc == 2 &&
         sl->slice_type_nos == AV_PICTURE_TYPE_B) {
         implicit_weight_table(h, sl, -1);
         if (FRAME_MBAFF(h)) {
             implicit_weight_table(h, sl, 0);
             implicit_weight_table(h, sl, 1);
         }
     }
 

     if (sl->slice_type_nos == AV_PICTURE_TYPE_B && !sl->direct_spatial_mv_pred)
         ff_h264_direct_dist_scale_factor(h, sl);
     ff_h264_direct_ref_list_init(h, sl);
 

     if (h->avctx->skip_loop_filter >= AVDISCARD_ALL ||

         (h->avctx->skip_loop_filter >= AVDISCARD_NONKEY &&

          h->nal_unit_type != H264_NAL_IDR_SLICE) ||

         (h->avctx->skip_loop_filter >= AVDISCARD_NONINTRA &&

          sl->slice_type_nos != AV_PICTURE_TYPE_I) ||

         (h->avctx->skip_loop_filter >= AVDISCARD_BIDIR  &&

          sl->slice_type_nos == AV_PICTURE_TYPE_B) ||

         (h->avctx->skip_loop_filter >= AVDISCARD_NONREF &&

          nal->ref_idc == 0))

         sl->deblocking_filter = 0;

     if (sl->deblocking_filter == 1 && h->max_contexts > 1) {

         if (h->avctx->flags2 & AV_CODEC_FLAG2_FAST) {

             /* Cheat slightly for speed:
              * Do not bother to deblock across slices. */

             sl->deblocking_filter = 2;

         } else {

             h->postpone_filter = 1;

         }
     }

     sl->qp_thresh = 15 -

                    FFMIN(sl->slice_alpha_c0_offset, sl->slice_beta_offset) -

                    FFMAX3(0,

                           h->ps.pps->chroma_qp_index_offset[0],
                           h->ps.pps->chroma_qp_index_offset[1]) +
                    6 * (h->ps.sps->bit_depth_luma - 8);

     sl->slice_num       = ++h->current_slice;

     if (sl->slice_num)

         h->slice_row[(sl->slice_num-1)&(MAX_SLICES-1)]= sl->resync_mb_y;
     if (   h->slice_row[sl->slice_num&(MAX_SLICES-1)] + 3 >= sl->resync_mb_y
         && h->slice_row[sl->slice_num&(MAX_SLICES-1)] <= sl->resync_mb_y

         && sl->slice_num >= MAX_SLICES) {

         //in case of ASO this check needs to be updated depending on how we decide to assign slice numbers in this case

         av_log(h->avctx, AV_LOG_WARNING, "Possibly too many slices (%d >= %d), increase MAX_SLICES and recompile if there are artifacts\n", sl->slice_num, MAX_SLICES);

     }
 
     for (j = 0; j < 2; j++) {
         int id_list[16];

         int *ref2frm = h->ref2frm[sl->slice_num & (MAX_SLICES - 1)][j];

         for (i = 0; i < 16; i++) {
             id_list[i] = 60;

             if (j < sl->list_count && i < sl->ref_count[j] &&

                 sl->ref_list[j][i].parent->f->buf[0]) {

                 int k;

                 AVBuffer *buf = sl->ref_list[j][i].parent->f->buf[0]->buffer;

                 for (k = 0; k < h->short_ref_count; k++)

                     if (h->short_ref[k]->f->buf[0]->buffer == buf) {

                         id_list[i] = k;
                         break;
                     }
                 for (k = 0; k < h->long_ref_count; k++)

                     if (h->long_ref[k] && h->long_ref[k]->f->buf[0]->buffer == buf) {

                         id_list[i] = h->short_ref_count + k;
                         break;
                     }
             }
         }
 
         ref2frm[0] =
         ref2frm[1] = -1;
         for (i = 0; i < 16; i++)

             ref2frm[i + 2] = 4 * id_list[i] + (sl->ref_list[j][i].reference & 3);

         ref2frm[18 + 0] =
         ref2frm[18 + 1] = -1;
         for (i = 16; i < 48; i++)
             ref2frm[i + 4] = 4 * id_list[(i - 16) >> 1] +

                              (sl->ref_list[j][i].reference & 3);

     }
 
     if (h->avctx->debug & FF_DEBUG_PICT_INFO) {
         av_log(h->avctx, AV_LOG_DEBUG,

                "slice:%d %s mb:%d %c%s%s frame:%d poc:%d/%d ref:%d/%d qp:%d loop:%d:%d:%d weight:%d%s %s\n",

                sl->slice_num,

                (h->picture_structure == PICT_FRAME ? "F" : h->picture_structure == PICT_TOP_FIELD ? "T" : "B"),

                sl->mb_y * h->mb_width + sl->mb_x,

                av_get_picture_type_char(sl->slice_type),
                sl->slice_type_fixed ? " fix" : "",

                nal->type == H264_NAL_IDR_SLICE ? " IDR" : "",

                h->poc.frame_num,

                h->cur_pic_ptr->field_poc[0],
                h->cur_pic_ptr->field_poc[1],

                sl->ref_count[0], sl->ref_count[1],

                sl->qscale,

                sl->deblocking_filter,
                sl->slice_alpha_c0_offset, sl->slice_beta_offset,

                sl->pwt.use_weight,
                sl->pwt.use_weight == 1 && sl->pwt.use_weight_chroma ? "c" : "",

                sl->slice_type == AV_PICTURE_TYPE_B ? (sl->direct_spatial_mv_pred ? "SPAT" : "TEMP") : "");

     }
 
     return 0;
 }
 

 int ff_h264_get_slice_type(const H264SliceContext *sl)

 {

     switch (sl->slice_type) {

     case AV_PICTURE_TYPE_P:
         return 0;
     case AV_PICTURE_TYPE_B:
         return 1;
     case AV_PICTURE_TYPE_I:
         return 2;
     case AV_PICTURE_TYPE_SP:
         return 3;
     case AV_PICTURE_TYPE_SI:
         return 4;
     default:
         return AVERROR_INVALIDDATA;
     }
 }
 

 static av_always_inline void fill_filter_caches_inter(const H264Context *h,

                                                       H264SliceContext *sl,

                                                       int mb_type, int top_xy,
                                                       int left_xy[LEFT_MBS],
                                                       int top_type,
                                                       int left_type[LEFT_MBS],
                                                       int mb_xy, int list)
 {
     int b_stride = h->b_stride;

     int16_t(*mv_dst)[2] = &sl->mv_cache[list][scan8[0]];
     int8_t *ref_cache   = &sl->ref_cache[list][scan8[0]];

     if (IS_INTER(mb_type) || IS_DIRECT(mb_type)) {
         if (USES_LIST(top_type, list)) {
             const int b_xy  = h->mb2b_xy[top_xy] + 3 * b_stride;
             const int b8_xy = 4 * top_xy + 2;

             const int *ref2frm = &h->ref2frm[h->slice_table[top_xy] & (MAX_SLICES - 1)][list][(MB_MBAFF(sl) ? 20 : 2)];

             AV_COPY128(mv_dst - 1 * 8, h->cur_pic.motion_val[list][b_xy + 0]);
             ref_cache[0 - 1 * 8] =

             ref_cache[1 - 1 * 8] = ref2frm[h->cur_pic.ref_index[list][b8_xy + 0]];

             ref_cache[2 - 1 * 8] =

             ref_cache[3 - 1 * 8] = ref2frm[h->cur_pic.ref_index[list][b8_xy + 1]];

         } else {
             AV_ZERO128(mv_dst - 1 * 8);
             AV_WN32A(&ref_cache[0 - 1 * 8], ((LIST_NOT_USED) & 0xFF) * 0x01010101u);
         }
 
         if (!IS_INTERLACED(mb_type ^ left_type[LTOP])) {
             if (USES_LIST(left_type[LTOP], list)) {
                 const int b_xy  = h->mb2b_xy[left_xy[LTOP]] + 3;
                 const int b8_xy = 4 * left_xy[LTOP] + 1;

                 const int *ref2frm = &h->ref2frm[h->slice_table[left_xy[LTOP]] & (MAX_SLICES - 1)][list][(MB_MBAFF(sl) ? 20 : 2)];

                 AV_COPY32(mv_dst - 1 +  0, h->cur_pic.motion_val[list][b_xy + b_stride * 0]);
                 AV_COPY32(mv_dst - 1 +  8, h->cur_pic.motion_val[list][b_xy + b_stride * 1]);
                 AV_COPY32(mv_dst - 1 + 16, h->cur_pic.motion_val[list][b_xy + b_stride * 2]);
                 AV_COPY32(mv_dst - 1 + 24, h->cur_pic.motion_val[list][b_xy + b_stride * 3]);
                 ref_cache[-1 +  0] =

                 ref_cache[-1 +  8] = ref2frm[h->cur_pic.ref_index[list][b8_xy + 2 * 0]];

                 ref_cache[-1 + 16] =

                 ref_cache[-1 + 24] = ref2frm[h->cur_pic.ref_index[list][b8_xy + 2 * 1]];

             } else {
                 AV_ZERO32(mv_dst - 1 +  0);
                 AV_ZERO32(mv_dst - 1 +  8);
                 AV_ZERO32(mv_dst - 1 + 16);
                 AV_ZERO32(mv_dst - 1 + 24);
                 ref_cache[-1 +  0] =
                 ref_cache[-1 +  8] =
                 ref_cache[-1 + 16] =
                 ref_cache[-1 + 24] = LIST_NOT_USED;
             }
         }
     }
 
     if (!USES_LIST(mb_type, list)) {
         fill_rectangle(mv_dst, 4, 4, 8, pack16to32(0, 0), 4);
         AV_WN32A(&ref_cache[0 * 8], ((LIST_NOT_USED) & 0xFF) * 0x01010101u);
         AV_WN32A(&ref_cache[1 * 8], ((LIST_NOT_USED) & 0xFF) * 0x01010101u);
         AV_WN32A(&ref_cache[2 * 8], ((LIST_NOT_USED) & 0xFF) * 0x01010101u);
         AV_WN32A(&ref_cache[3 * 8], ((LIST_NOT_USED) & 0xFF) * 0x01010101u);
         return;
     }
 
     {
         int8_t *ref = &h->cur_pic.ref_index[list][4 * mb_xy];

         const int *ref2frm = &h->ref2frm[sl->slice_num & (MAX_SLICES - 1)][list][(MB_MBAFF(sl) ? 20 : 2)];

         uint32_t ref01 = (pack16to32(ref2frm[ref[0]], ref2frm[ref[1]]) & 0x00FF00FF) * 0x0101;
         uint32_t ref23 = (pack16to32(ref2frm[ref[2]], ref2frm[ref[3]]) & 0x00FF00FF) * 0x0101;

         AV_WN32A(&ref_cache[0 * 8], ref01);
         AV_WN32A(&ref_cache[1 * 8], ref01);
         AV_WN32A(&ref_cache[2 * 8], ref23);
         AV_WN32A(&ref_cache[3 * 8], ref23);
     }
 
     {

         int16_t(*mv_src)[2] = &h->cur_pic.motion_val[list][4 * sl->mb_x + 4 * sl->mb_y * b_stride];

         AV_COPY128(mv_dst + 8 * 0, mv_src + 0 * b_stride);
         AV_COPY128(mv_dst + 8 * 1, mv_src + 1 * b_stride);
         AV_COPY128(mv_dst + 8 * 2, mv_src + 2 * b_stride);
         AV_COPY128(mv_dst + 8 * 3, mv_src + 3 * b_stride);
     }
 }
 
 /**
  * @return non zero if the loop filter can be skipped
  */

 static int fill_filter_caches(const H264Context *h, H264SliceContext *sl, int mb_type)

 {

     const int mb_xy = sl->mb_xy;

     int top_xy, left_xy[LEFT_MBS];
     int top_type, left_type[LEFT_MBS];
     uint8_t *nnz;
     uint8_t *nnz_cache;
 

     top_xy = mb_xy - (h->mb_stride << MB_FIELD(sl));

 
     left_xy[LBOT] = left_xy[LTOP] = mb_xy - 1;
     if (FRAME_MBAFF(h)) {
         const int left_mb_field_flag = IS_INTERLACED(h->cur_pic.mb_type[mb_xy - 1]);
         const int curr_mb_field_flag = IS_INTERLACED(mb_type);

         if (sl->mb_y & 1) {

             if (left_mb_field_flag != curr_mb_field_flag)
                 left_xy[LTOP] -= h->mb_stride;
         } else {
             if (curr_mb_field_flag)
                 top_xy += h->mb_stride &
                           (((h->cur_pic.mb_type[top_xy] >> 7) & 1) - 1);
             if (left_mb_field_flag != curr_mb_field_flag)
                 left_xy[LBOT] += h->mb_stride;
         }
     }
 

     sl->top_mb_xy        = top_xy;
     sl->left_mb_xy[LTOP] = left_xy[LTOP];
     sl->left_mb_xy[LBOT] = left_xy[LBOT];

     {
         /* For sufficiently low qp, filtering wouldn't do anything.
          * This is a conservative estimate: could also check beta_offset
          * and more accurate chroma_qp. */

         int qp_thresh = sl->qp_thresh; // FIXME strictly we should store qp_thresh for each mb of a slice

         int qp        = h->cur_pic.qscale_table[mb_xy];
         if (qp <= qp_thresh &&
             (left_xy[LTOP] < 0 ||
              ((qp + h->cur_pic.qscale_table[left_xy[LTOP]] + 1) >> 1) <= qp_thresh) &&
             (top_xy < 0 ||
              ((qp + h->cur_pic.qscale_table[top_xy] + 1) >> 1) <= qp_thresh)) {
             if (!FRAME_MBAFF(h))
                 return 1;
             if ((left_xy[LTOP] < 0 ||
                  ((qp + h->cur_pic.qscale_table[left_xy[LBOT]] + 1) >> 1) <= qp_thresh) &&
                 (top_xy < h->mb_stride ||
                  ((qp + h->cur_pic.qscale_table[top_xy - h->mb_stride] + 1) >> 1) <= qp_thresh))
                 return 1;
         }
     }
 
     top_type        = h->cur_pic.mb_type[top_xy];
     left_type[LTOP] = h->cur_pic.mb_type[left_xy[LTOP]];
     left_type[LBOT] = h->cur_pic.mb_type[left_xy[LBOT]];

     if (sl->deblocking_filter == 2) {

         if (h->slice_table[top_xy] != sl->slice_num)

             top_type = 0;

         if (h->slice_table[left_xy[LBOT]] != sl->slice_num)

             left_type[LTOP] = left_type[LBOT] = 0;
     } else {
         if (h->slice_table[top_xy] == 0xFFFF)
             top_type = 0;
         if (h->slice_table[left_xy[LBOT]] == 0xFFFF)
             left_type[LTOP] = left_type[LBOT] = 0;
     }

     sl->top_type        = top_type;
     sl->left_type[LTOP] = left_type[LTOP];
     sl->left_type[LBOT] = left_type[LBOT];

 
     if (IS_INTRA(mb_type))
         return 0;
 

     fill_filter_caches_inter(h, sl, mb_type, top_xy, left_xy,

                              top_type, left_type, mb_xy, 0);

     if (sl->list_count == 2)

         fill_filter_caches_inter(h, sl, mb_type, top_xy, left_xy,

                                  top_type, left_type, mb_xy, 1);
 
     nnz       = h->non_zero_count[mb_xy];

     nnz_cache = sl->non_zero_count_cache;

     AV_COPY32(&nnz_cache[4 + 8 * 1], &nnz[0]);
     AV_COPY32(&nnz_cache[4 + 8 * 2], &nnz[4]);
     AV_COPY32(&nnz_cache[4 + 8 * 3], &nnz[8]);
     AV_COPY32(&nnz_cache[4 + 8 * 4], &nnz[12]);

     sl->cbp = h->cbp_table[mb_xy];

 
     if (top_type) {
         nnz = h->non_zero_count[top_xy];
         AV_COPY32(&nnz_cache[4 + 8 * 0], &nnz[3 * 4]);
     }
 
     if (left_type[LTOP]) {
         nnz = h->non_zero_count[left_xy[LTOP]];
         nnz_cache[3 + 8 * 1] = nnz[3 + 0 * 4];
         nnz_cache[3 + 8 * 2] = nnz[3 + 1 * 4];
         nnz_cache[3 + 8 * 3] = nnz[3 + 2 * 4];
         nnz_cache[3 + 8 * 4] = nnz[3 + 3 * 4];
     }
 
     /* CAVLC 8x8dct requires NNZ values for residual decoding that differ
      * from what the loop filter needs */

     if (!CABAC(h) && h->ps.pps->transform_8x8_mode) {

         if (IS_8x8DCT(top_type)) {
             nnz_cache[4 + 8 * 0] =
             nnz_cache[5 + 8 * 0] = (h->cbp_table[top_xy] & 0x4000) >> 12;
             nnz_cache[6 + 8 * 0] =
             nnz_cache[7 + 8 * 0] = (h->cbp_table[top_xy] & 0x8000) >> 12;
         }
         if (IS_8x8DCT(left_type[LTOP])) {
             nnz_cache[3 + 8 * 1] =
             nnz_cache[3 + 8 * 2] = (h->cbp_table[left_xy[LTOP]] & 0x2000) >> 12; // FIXME check MBAFF
         }
         if (IS_8x8DCT(left_type[LBOT])) {
             nnz_cache[3 + 8 * 3] =
             nnz_cache[3 + 8 * 4] = (h->cbp_table[left_xy[LBOT]] & 0x8000) >> 12; // FIXME check MBAFF
         }
 
         if (IS_8x8DCT(mb_type)) {
             nnz_cache[scan8[0]] =
             nnz_cache[scan8[1]] =
             nnz_cache[scan8[2]] =

             nnz_cache[scan8[3]] = (sl->cbp & 0x1000) >> 12;

 
             nnz_cache[scan8[0 + 4]] =
             nnz_cache[scan8[1 + 4]] =
             nnz_cache[scan8[2 + 4]] =

             nnz_cache[scan8[3 + 4]] = (sl->cbp & 0x2000) >> 12;

 
             nnz_cache[scan8[0 + 8]] =
             nnz_cache[scan8[1 + 8]] =
             nnz_cache[scan8[2 + 8]] =

             nnz_cache[scan8[3 + 8]] = (sl->cbp & 0x4000) >> 12;

 
             nnz_cache[scan8[0 + 12]] =
             nnz_cache[scan8[1 + 12]] =
             nnz_cache[scan8[2 + 12]] =

             nnz_cache[scan8[3 + 12]] = (sl->cbp & 0x8000) >> 12;

         }
     }
 
     return 0;
 }
 

 static void loop_filter(const H264Context *h, H264SliceContext *sl, int start_x, int end_x)

 {
     uint8_t *dest_y, *dest_cb, *dest_cr;
     int linesize, uvlinesize, mb_x, mb_y;

     const int end_mb_y       = sl->mb_y + FRAME_MBAFF(h);

     const int old_slice_type = sl->slice_type;

     const int pixel_shift    = h->pixel_shift;
     const int block_h        = 16 >> h->chroma_y_shift;
 

     if (h->postpone_filter)
         return;
 

     if (sl->deblocking_filter) {

         for (mb_x = start_x; mb_x < end_x; mb_x++)
             for (mb_y = end_mb_y - FRAME_MBAFF(h); mb_y <= end_mb_y; mb_y++) {
                 int mb_xy, mb_type;

                 mb_xy         = sl->mb_xy = mb_x + mb_y * h->mb_stride;

                 mb_type       = h->cur_pic.mb_type[mb_xy];
 
                 if (FRAME_MBAFF(h))

                     sl->mb_mbaff               =

                     sl->mb_field_decoding_flag = !!IS_INTERLACED(mb_type);

                 sl->mb_x = mb_x;
                 sl->mb_y = mb_y;

                 dest_y  = h->cur_pic.f->data[0] +

                           ((mb_x << pixel_shift) + mb_y * sl->linesize) * 16;

                 dest_cb = h->cur_pic.f->data[1] +

                           (mb_x << pixel_shift) * (8 << CHROMA444(h)) +

                           mb_y * sl->uvlinesize * block_h;

                 dest_cr = h->cur_pic.f->data[2] +

                           (mb_x << pixel_shift) * (8 << CHROMA444(h)) +

                           mb_y * sl->uvlinesize * block_h;

                 // FIXME simplify above
 

                 if (MB_FIELD(sl)) {

                     linesize   = sl->mb_linesize   = sl->linesize   * 2;
                     uvlinesize = sl->mb_uvlinesize = sl->uvlinesize * 2;

                     if (mb_y & 1) { // FIXME move out of this function?

                         dest_y  -= sl->linesize   * 15;
                         dest_cb -= sl->uvlinesize * (block_h - 1);
                         dest_cr -= sl->uvlinesize * (block_h - 1);

                     }
                 } else {

                     linesize   = sl->mb_linesize   = sl->linesize;
                     uvlinesize = sl->mb_uvlinesize = sl->uvlinesize;

                 }

                 backup_mb_border(h, sl, dest_y, dest_cb, dest_cr, linesize,

                                  uvlinesize, 0);

                 if (fill_filter_caches(h, sl, mb_type))

                     continue;

                 sl->chroma_qp[0] = get_chroma_qp(h->ps.pps, 0, h->cur_pic.qscale_table[mb_xy]);
                 sl->chroma_qp[1] = get_chroma_qp(h->ps.pps, 1, h->cur_pic.qscale_table[mb_xy]);

 
                 if (FRAME_MBAFF(h)) {

                     ff_h264_filter_mb(h, sl, mb_x, mb_y, dest_y, dest_cb, dest_cr,

                                       linesize, uvlinesize);
                 } else {

                     ff_h264_filter_mb_fast(h, sl, mb_x, mb_y, dest_y, dest_cb,

                                            dest_cr, linesize, uvlinesize);
                 }
             }
     }

     sl->slice_type  = old_slice_type;

     sl->mb_x         = end_x;
     sl->mb_y         = end_mb_y - FRAME_MBAFF(h);

     sl->chroma_qp[0] = get_chroma_qp(h->ps.pps, 0, sl->qscale);
     sl->chroma_qp[1] = get_chroma_qp(h->ps.pps, 1, sl->qscale);

 }
 

 static void predict_field_decoding_flag(const H264Context *h, H264SliceContext *sl)

 {

     const int mb_xy = sl->mb_x + sl->mb_y * h->mb_stride;

     int mb_type     = (h->slice_table[mb_xy - 1] == sl->slice_num) ?

                       h->cur_pic.mb_type[mb_xy - 1] :

                       (h->slice_table[mb_xy - h->mb_stride] == sl->slice_num) ?

                       h->cur_pic.mb_type[mb_xy - h->mb_stride] : 0;

     sl->mb_mbaff    = sl->mb_field_decoding_flag = IS_INTERLACED(mb_type) ? 1 : 0;

 }
 
 /**
  * Draw edges and report progress for the last MB row.
  */

 static void decode_finish_row(const H264Context *h, H264SliceContext *sl)

 {

     int top            = 16 * (sl->mb_y      >> FIELD_PICTURE(h));

     int pic_height     = 16 *  h->mb_height >> FIELD_PICTURE(h);
     int height         =  16      << FRAME_MBAFF(h);
     int deblock_border = (16 + 4) << FRAME_MBAFF(h);
 

     if (sl->deblocking_filter) {

         if ((top + height) >= pic_height)
             height += deblock_border;
         top -= deblock_border;
     }
 
     if (top >= pic_height || (top + height) < 0)
         return;
 
     height = FFMIN(height, pic_height - top);
     if (top < 0) {
         height = top + height;
         top    = 0;
     }
 

     ff_h264_draw_horiz_band(h, sl, top, height);

     if (h->droppable || sl->h264->slice_ctx[0].er.error_occurred)

         return;
 
     ff_thread_report_progress(&h->cur_pic_ptr->tf, top + height - 1,
                               h->picture_structure == PICT_BOTTOM_FIELD);
 }
 

 static void er_add_slice(H264SliceContext *sl,

                          int startx, int starty,

                          int endx, int endy, int status)
 {

     if (!sl->h264->enable_er)
         return;
 

     if (CONFIG_ERROR_RESILIENCE) {

         ERContext *er = &sl->h264->slice_ctx[0].er;

         ff_er_add_slice(er, startx, starty, endx, endy, status);
     }

 }
 
 static int decode_slice(struct AVCodecContext *avctx, void *arg)
 {

     H264SliceContext *sl = arg;

     const H264Context *h = sl->h264;

     int lf_x_start = sl->mb_x;

     int orig_deblock = sl->deblocking_filter;

     int ret;
 

     sl->linesize   = h->cur_pic_ptr->f->linesize[0];
     sl->uvlinesize = h->cur_pic_ptr->f->linesize[1];

 
     ret = alloc_scratch_buffers(sl, sl->linesize);

     if (ret < 0)
         return ret;

     sl->mb_skip_run = -1;

     av_assert0(h->block_offset[15] == (4 * ((scan8[15] - scan8[0]) & 7) << h->pixel_shift) + 4 * sl->linesize * ((scan8[15] - scan8[0]) >> 3));

     if (h->postpone_filter)
         sl->deblocking_filter = 0;
 

     sl->is_complex = FRAME_MBAFF(h) || h->picture_structure != PICT_FRAME ||

                      (CONFIG_GRAY && (h->flags & AV_CODEC_FLAG_GRAY));

     if (!(h->avctx->active_thread_type & FF_THREAD_SLICE) && h->picture_structure == PICT_FRAME && h->slice_ctx[0].er.error_status_table) {

         const int start_i  = av_clip(sl->resync_mb_x + sl->resync_mb_y * h->mb_width, 0, h->mb_num - 1);

         if (start_i) {

             int prev_status = h->slice_ctx[0].er.error_status_table[h->slice_ctx[0].er.mb_index2xy[start_i - 1]];

             prev_status &= ~ VP_START;
             if (prev_status != (ER_MV_END | ER_DC_END | ER_AC_END))

                 h->slice_ctx[0].er.error_occurred = 1;

         }
     }
 

     if (h->ps.pps->cabac) {

         /* realign */

         align_get_bits(&sl->gb);

 
         /* init cabac */

         ret = ff_init_cabac_decoder(&sl->cabac,

                               sl->gb.buffer + get_bits_count(&sl->gb) / 8,
                               (get_bits_left(&sl->gb) + 7) / 8);

         if (ret < 0)
             return ret;

         ff_h264_init_cabac_states(h, sl);

 
         for (;;) {
             // START_TIMER

             int ret, eos;

             if (sl->mb_x + sl->mb_y * h->mb_width >= sl->next_slice_idx) {
                 av_log(h->avctx, AV_LOG_ERROR, "Slice overlaps with next at %d\n",
                        sl->next_slice_idx);

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x,
                              sl->mb_y, ER_MB_ERROR);
                 return AVERROR_INVALIDDATA;
             }
 
             ret = ff_h264_decode_mb_cabac(h, sl);

             // STOP_TIMER("decode_mb_cabac")
 
             if (ret >= 0)

                 ff_h264_hl_decode_mb(h, sl);

 
             // FIXME optimal? or let mb_decode decode 16x32 ?
             if (ret >= 0 && FRAME_MBAFF(h)) {

                 sl->mb_y++;

                 ret = ff_h264_decode_mb_cabac(h, sl);

 
                 if (ret >= 0)

                     ff_h264_hl_decode_mb(h, sl);

                 sl->mb_y--;

             }

             eos = get_cabac_terminate(&sl->cabac);

 
             if ((h->workaround_bugs & FF_BUG_TRUNCATED) &&

                 sl->cabac.bytestream > sl->cabac.bytestream_end + 2) {

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x - 1,

                              sl->mb_y, ER_MB_END);
                 if (sl->mb_x >= lf_x_start)
                     loop_filter(h, sl, lf_x_start, sl->mb_x + 1);

                 goto finish;

             }

             if (sl->cabac.bytestream > sl->cabac.bytestream_end + 2 )
                 av_log(h->avctx, AV_LOG_DEBUG, "bytestream overread %"PTRDIFF_SPECIFIER"\n", sl->cabac.bytestream_end - sl->cabac.bytestream);
             if (ret < 0 || sl->cabac.bytestream > sl->cabac.bytestream_end + 4) {

                 av_log(h->avctx, AV_LOG_ERROR,

                        "error while decoding MB %d %d, bytestream %"PTRDIFF_SPECIFIER"\n",

                        sl->mb_x, sl->mb_y,

                        sl->cabac.bytestream_end - sl->cabac.bytestream);

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x,

                              sl->mb_y, ER_MB_ERROR);

                 return AVERROR_INVALIDDATA;
             }
 

             if (++sl->mb_x >= h->mb_width) {
                 loop_filter(h, sl, lf_x_start, sl->mb_x);
                 sl->mb_x = lf_x_start = 0;

                 decode_finish_row(h, sl);

                 ++sl->mb_y;

                 if (FIELD_OR_MBAFF_PICTURE(h)) {

                     ++sl->mb_y;
                     if (FRAME_MBAFF(h) && sl->mb_y < h->mb_height)

                         predict_field_decoding_flag(h, sl);

                 }
             }
 

             if (eos || sl->mb_y >= h->mb_height) {

                 ff_tlog(h->avctx, "slice end %d %d\n",

                         get_bits_count(&sl->gb), sl->gb.size_in_bits);

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x - 1,

                              sl->mb_y, ER_MB_END);
                 if (sl->mb_x > lf_x_start)
                     loop_filter(h, sl, lf_x_start, sl->mb_x);

                 goto finish;

             }
         }
     } else {
         for (;;) {

             int ret;
 

             if (sl->mb_x + sl->mb_y * h->mb_width >= sl->next_slice_idx) {
                 av_log(h->avctx, AV_LOG_ERROR, "Slice overlaps with next at %d\n",
                        sl->next_slice_idx);

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x,
                              sl->mb_y, ER_MB_ERROR);
                 return AVERROR_INVALIDDATA;
             }
 
             ret = ff_h264_decode_mb_cavlc(h, sl);

 
             if (ret >= 0)

                 ff_h264_hl_decode_mb(h, sl);

 
             // FIXME optimal? or let mb_decode decode 16x32 ?
             if (ret >= 0 && FRAME_MBAFF(h)) {

                 sl->mb_y++;

                 ret = ff_h264_decode_mb_cavlc(h, sl);

 
                 if (ret >= 0)

                     ff_h264_hl_decode_mb(h, sl);

                 sl->mb_y--;

             }
 
             if (ret < 0) {
                 av_log(h->avctx, AV_LOG_ERROR,

                        "error while decoding MB %d %d\n", sl->mb_x, sl->mb_y);

                 er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x,

                              sl->mb_y, ER_MB_ERROR);

                 return ret;
             }
 

             if (++sl->mb_x >= h->mb_width) {
                 loop_filter(h, sl, lf_x_start, sl->mb_x);
                 sl->mb_x = lf_x_start = 0;

                 decode_finish_row(h, sl);

                 ++sl->mb_y;

                 if (FIELD_OR_MBAFF_PICTURE(h)) {

                     ++sl->mb_y;
                     if (FRAME_MBAFF(h) && sl->mb_y < h->mb_height)

                         predict_field_decoding_flag(h, sl);

                 }

                 if (sl->mb_y >= h->mb_height) {

                     ff_tlog(h->avctx, "slice end %d %d\n",

                             get_bits_count(&sl->gb), sl->gb.size_in_bits);

                     if (   get_bits_left(&sl->gb) == 0
                         || get_bits_left(&sl->gb) > 0 && !(h->avctx->err_recognition & AV_EF_AGGRESSIVE)) {

                         er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y,

                                      sl->mb_x - 1, sl->mb_y, ER_MB_END);

                         goto finish;

                     } else {

                         er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y,

                                      sl->mb_x, sl->mb_y, ER_MB_END);

 
                         return AVERROR_INVALIDDATA;
                     }
                 }
             }
 

             if (get_bits_left(&sl->gb) <= 0 && sl->mb_skip_run <= 0) {

                 ff_tlog(h->avctx, "slice end %d %d\n",

                         get_bits_count(&sl->gb), sl->gb.size_in_bits);

                 if (get_bits_left(&sl->gb) == 0) {

                     er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y,

                                  sl->mb_x - 1, sl->mb_y, ER_MB_END);
                     if (sl->mb_x > lf_x_start)
                         loop_filter(h, sl, lf_x_start, sl->mb_x);

                     goto finish;

                 } else {

                     er_add_slice(sl, sl->resync_mb_x, sl->resync_mb_y, sl->mb_x,

                                  sl->mb_y, ER_MB_ERROR);

 
                     return AVERROR_INVALIDDATA;
                 }
             }
         }
     }

 
 finish:
     sl->deblocking_filter = orig_deblock;
     return 0;

 }
 
 /**
  * Call decode_slice() for each context.
  *
  * @param h h264 master context
  * @param context_count number of contexts to execute
  */
 int ff_h264_execute_decode_slices(H264Context *h, unsigned context_count)
 {
     AVCodecContext *const avctx = h->avctx;

     H264SliceContext *sl;

     int i, j;

     av_assert0(context_count && h->slice_ctx[context_count - 1].mb_y < h->mb_height);

     h->slice_ctx[0].next_slice_idx = INT_MAX;

     if (h->avctx->hwaccel
 #if FF_API_CAP_VDPAU
         || h->avctx->codec->capabilities & AV_CODEC_CAP_HWACCEL_VDPAU
 #endif
         )

         return 0;
     if (context_count == 1) {

         int ret;
 
         h->slice_ctx[0].next_slice_idx = h->mb_width * h->mb_height;

         h->postpone_filter = 0;

 
         ret = decode_slice(avctx, &h->slice_ctx[0]);

         h->mb_y = h->slice_ctx[0].mb_y;
         return ret;

     } else {

         av_assert0(context_count > 0);

         for (i = 0; i < context_count; i++) {

             int next_slice_idx = h->mb_width * h->mb_height;
             int slice_idx;
 

             sl                 = &h->slice_ctx[i];

             if (CONFIG_ERROR_RESILIENCE) {

                 sl->er.error_count = 0;

             }

 
             /* make sure none of those slices overlap */
             slice_idx = sl->mb_y * h->mb_width + sl->mb_x;

             for (j = 0; j < context_count; j++) {
                 H264SliceContext *sl2 = &h->slice_ctx[j];

                 int        slice_idx2 = sl2->mb_y * h->mb_width + sl2->mb_x;

                 if (i == j || slice_idx2 < slice_idx)

                     continue;

                 next_slice_idx = FFMIN(next_slice_idx, slice_idx2);

             }

             sl->next_slice_idx = next_slice_idx;

         }
 

         avctx->execute(avctx, decode_slice, h->slice_ctx,
                        NULL, context_count, sizeof(h->slice_ctx[0]));

 
         /* pull back stuff from slices to master context */

         sl                   = &h->slice_ctx[context_count - 1];
         h->mb_y              = sl->mb_y;

         if (CONFIG_ERROR_RESILIENCE) {
             for (i = 1; i < context_count; i++)

                 h->slice_ctx[0].er.error_count += h->slice_ctx[i].er.error_count;

         }

 
         if (h->postpone_filter) {
             h->postpone_filter = 0;
 
             for (i = 0; i < context_count; i++) {
                 int y_end, x_end;
 
                 sl = &h->slice_ctx[i];
                 y_end = FFMIN(sl->mb_y + 1, h->mb_height);
                 x_end = (sl->mb_y >= h->mb_height) ? h->mb_width : sl->mb_x;
 
                 for (j = sl->resync_mb_y; j < y_end; j += 1 + FIELD_OR_MBAFF_PICTURE(h)) {
                     sl->mb_y = j;
                     loop_filter(h, sl, j > sl->resync_mb_y ? 0 : sl->resync_mb_x,
                                 j == y_end - 1 ? x_end : h->mb_width);
                 }
             }
         }

     }
 
     return 0;
 }