/*
  * VC3/DNxHD decoder.

  * Copyright (c) 2007 SmartJog S.A., Baptiste Coudurier <baptiste dot coudurier at smartjog dot com>

  * Copyright (c) 2011 MirriAd Ltd

  * Copyright (c) 2015 Christophe Gisquet

  *
  * 10 bit support added by MirriAd Ltd, Joseph Artsimovich <joseph@mirriad.com>

  * Slice multithreading and MB interlaced support added by Christophe Gisquet

  *
  * 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
  */
 

 #include "libavutil/imgutils.h"

 #include "libavutil/timer.h"

 #include "avcodec.h"

 #include "blockdsp.h"

 #define  UNCHECKED_BITSTREAM_READER 1

 #include "get_bits.h"

 #include "dnxhddata.h"

 #include "idctdsp.h"

 #include "internal.h"

 #include "profiles.h"

 #include "thread.h"

 typedef struct RowContext {
     DECLARE_ALIGNED(16, int16_t, blocks)[12][64];
     int luma_scale[64];
     int chroma_scale[64];
     GetBitContext gb;
     int last_dc[3];
     int last_qscale;

     int errors;

     /** -1:not set yet  0:off=RGB  1:on=YUV  2:variable */
     int format;

 } RowContext;
 

 typedef struct DNXHDContext {

     AVCodecContext *avctx;

     RowContext *rows;

     BlockDSPContext bdsp;

     const uint8_t* buf;
     int buf_size;

     int64_t cid;                        ///< compression id

     unsigned int width, height;

     enum AVPixelFormat pix_fmt;

     unsigned int mb_width, mb_height;

     uint32_t mb_scan_index[512];

     int data_offset;                    // End of mb_scan_index, where macroblocks start

     int cur_field;                      ///< current interlaced field
     VLC ac_vlc, dc_vlc, run_vlc;

     IDCTDSPContext idsp;

     ScanTable scantable;

     const CIDEntry *cid_table;

     int bit_depth; // 8, 10, 12 or 0 if not initialized at all.

     int is_444;

     int mbaff;

     int act;

     int (*decode_dct_block)(const struct DNXHDContext *ctx,

                             RowContext *row, int n);

 } DNXHDContext;
 
 #define DNXHD_VLC_BITS 9

 #define DNXHD_DC_VLC_BITS 7

 static int dnxhd_decode_dct_block_8(const DNXHDContext *ctx,

                                     RowContext *row, int n);

 static int dnxhd_decode_dct_block_10(const DNXHDContext *ctx,

                                      RowContext *row, int n);

 static int dnxhd_decode_dct_block_10_444(const DNXHDContext *ctx,

                                          RowContext *row, int n);

 static int dnxhd_decode_dct_block_12(const DNXHDContext *ctx,
                                      RowContext *row, int n);
 static int dnxhd_decode_dct_block_12_444(const DNXHDContext *ctx,
                                          RowContext *row, int n);

 static av_cold int dnxhd_decode_init(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 
     ctx->avctx = avctx;

     ctx->cid = -1;

     if (avctx->colorspace == AVCOL_SPC_UNSPECIFIED) {
         avctx->colorspace = AVCOL_SPC_BT709;
     }

     avctx->coded_width  = FFALIGN(avctx->width,  16);
     avctx->coded_height = FFALIGN(avctx->height, 16);
 

     ctx->rows = av_mallocz_array(avctx->thread_count, sizeof(RowContext));
     if (!ctx->rows)
         return AVERROR(ENOMEM);
 

     return 0;
 }
 

 static int dnxhd_init_vlc(DNXHDContext *ctx, uint32_t cid, int bitdepth)

 {

     if (cid != ctx->cid) {

         int index;
 

         if ((index = ff_dnxhd_get_cid_table(cid)) < 0) {

             av_log(ctx->avctx, AV_LOG_ERROR, "unsupported cid %"PRIu32"\n", cid);

             return AVERROR(ENOSYS);

         }

         if (ff_dnxhd_cid_table[index].bit_depth != bitdepth &&

             ff_dnxhd_cid_table[index].bit_depth != DNXHD_VARIABLE) {

             av_log(ctx->avctx, AV_LOG_ERROR, "bit depth mismatches %d %d\n", ff_dnxhd_cid_table[index].bit_depth, bitdepth);

             return AVERROR_INVALIDDATA;
         }

         ctx->cid_table = &ff_dnxhd_cid_table[index];

         av_log(ctx->avctx, AV_LOG_VERBOSE, "Profile cid %"PRIu32".\n", cid);

         ff_free_vlc(&ctx->ac_vlc);
         ff_free_vlc(&ctx->dc_vlc);
         ff_free_vlc(&ctx->run_vlc);

         init_vlc(&ctx->ac_vlc, DNXHD_VLC_BITS, 257,

                  ctx->cid_table->ac_bits, 1, 1,
                  ctx->cid_table->ac_codes, 2, 2, 0);

         init_vlc(&ctx->dc_vlc, DNXHD_DC_VLC_BITS, bitdepth > 8 ? 14 : 12,

                  ctx->cid_table->dc_bits, 1, 1,
                  ctx->cid_table->dc_codes, 1, 1, 0);

         init_vlc(&ctx->run_vlc, DNXHD_VLC_BITS, 62,

                  ctx->cid_table->run_bits, 1, 1,
                  ctx->cid_table->run_codes, 2, 2, 0);

         ctx->cid = cid;

     }
     return 0;
 }
 

 static av_cold int dnxhd_decode_init_thread_copy(AVCodecContext *avctx)
 {
     DNXHDContext *ctx = avctx->priv_data;
 

     ctx->avctx = avctx;

     // make sure VLC tables will be loaded when cid is parsed
     ctx->cid = -1;
 
     ctx->rows = av_mallocz_array(avctx->thread_count, sizeof(RowContext));
     if (!ctx->rows)
         return AVERROR(ENOMEM);
 
     return 0;
 }
 

 static int dnxhd_get_profile(int cid)
 {
     switch(cid) {
     case 1270:
         return FF_PROFILE_DNXHR_444;
     case 1271:
         return FF_PROFILE_DNXHR_HQX;
     case 1272:
         return FF_PROFILE_DNXHR_HQ;
     case 1273:
         return FF_PROFILE_DNXHR_SQ;
     case 1274:
         return FF_PROFILE_DNXHR_LB;
     }
     return FF_PROFILE_DNXHD;
 }
 

 static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,

                                const uint8_t *buf, int buf_size,
                                int first_field)

 {

     int i, cid, ret;

     int old_bit_depth = ctx->bit_depth, bitdepth;

     uint64_t header_prefix;

     if (buf_size < 0x280) {

         av_log(ctx->avctx, AV_LOG_ERROR,
                "buffer too small (%d < 640).\n", buf_size);

         return AVERROR_INVALIDDATA;

     }

     header_prefix = ff_dnxhd_parse_header_prefix(buf);

     if (header_prefix == 0) {

         av_log(ctx->avctx, AV_LOG_ERROR,
                "unknown header 0x%02X 0x%02X 0x%02X 0x%02X 0x%02X\n",
                buf[0], buf[1], buf[2], buf[3], buf[4]);

         return AVERROR_INVALIDDATA;

     }

     if (buf[5] & 2) { /* interlaced */
         ctx->cur_field = buf[5] & 1;

         frame->interlaced_frame = 1;
         frame->top_field_first  = first_field ^ ctx->cur_field;

         av_log(ctx->avctx, AV_LOG_DEBUG,
                "interlaced %d, cur field %d\n", buf[5] & 3, ctx->cur_field);

     } else {
         ctx->cur_field = 0;

     }

     ctx->mbaff = (buf[0x6] >> 5) & 1;

 
     ctx->height = AV_RB16(buf + 0x18);
     ctx->width  = AV_RB16(buf + 0x1a);
 

     switch(buf[0x21] >> 5) {

     case 1: bitdepth = 8; break;
     case 2: bitdepth = 10; break;
     case 3: bitdepth = 12; break;

     default:
         av_log(ctx->avctx, AV_LOG_ERROR,
                "Unknown bitdepth indicator (%d)\n", buf[0x21] >> 5);
         return AVERROR_INVALIDDATA;
     }

 
     cid = AV_RB32(buf + 0x28);

 
     ctx->avctx->profile = dnxhd_get_profile(cid);
 

     if ((ret = dnxhd_init_vlc(ctx, cid, bitdepth)) < 0)
         return ret;
     if (ctx->mbaff && ctx->cid_table->cid != 1260)
         av_log(ctx->avctx, AV_LOG_WARNING,
                "Adaptive MB interlace flag in an unsupported profile.\n");
 
     ctx->act = buf[0x2C] & 7;
     if (ctx->act && ctx->cid_table->cid != 1256 && ctx->cid_table->cid != 1270)
         av_log(ctx->avctx, AV_LOG_WARNING,
                "Adaptive color transform in an unsupported profile.\n");

     ctx->is_444 = (buf[0x2C] >> 6) & 1;
     if (ctx->is_444) {

         if (bitdepth == 8) {

             avpriv_request_sample(ctx->avctx, "4:4:4 8 bits");

             return AVERROR_INVALIDDATA;

         } else if (bitdepth == 10) {

             ctx->decode_dct_block = dnxhd_decode_dct_block_10_444;

             ctx->pix_fmt = ctx->act ? AV_PIX_FMT_YUV444P10
                                     : AV_PIX_FMT_GBRP10;

         } else {
             ctx->decode_dct_block = dnxhd_decode_dct_block_12_444;

             ctx->pix_fmt = ctx->act ? AV_PIX_FMT_YUV444P12
                                     : AV_PIX_FMT_GBRP12;

         }

     } else if (bitdepth == 12) {

         ctx->decode_dct_block = dnxhd_decode_dct_block_12;
         ctx->pix_fmt = AV_PIX_FMT_YUV422P12;

     } else if (bitdepth == 10) {

         if (ctx->avctx->profile == FF_PROFILE_DNXHR_HQX)
             ctx->decode_dct_block = dnxhd_decode_dct_block_10_444;
         else
             ctx->decode_dct_block = dnxhd_decode_dct_block_10;

         ctx->pix_fmt = AV_PIX_FMT_YUV422P10;

     } else {

         ctx->decode_dct_block = dnxhd_decode_dct_block_8;
         ctx->pix_fmt = AV_PIX_FMT_YUV422P;

     }

 
     ctx->avctx->bits_per_raw_sample = ctx->bit_depth = bitdepth;

     if (ctx->bit_depth != old_bit_depth) {
         ff_blockdsp_init(&ctx->bdsp, ctx->avctx);
         ff_idctdsp_init(&ctx->idsp, ctx->avctx);

         ff_init_scantable(ctx->idsp.idct_permutation, &ctx->scantable,
                           ff_zigzag_direct);

     }

     // make sure profile size constraints are respected
     // DNx100 allows 1920->1440 and 1280->960 subsampling

     if (ctx->width != ctx->cid_table->width &&
         ctx->cid_table->width != DNXHD_VARIABLE) {

         av_reduce(&ctx->avctx->sample_aspect_ratio.num,
                   &ctx->avctx->sample_aspect_ratio.den,
                   ctx->width, ctx->cid_table->width, 255);
         ctx->width = ctx->cid_table->width;
     }
 

     if (buf_size < ctx->cid_table->coding_unit_size) {

         av_log(ctx->avctx, AV_LOG_ERROR, "incorrect frame size (%d < %u).\n",

                buf_size, ctx->cid_table->coding_unit_size);

         return AVERROR_INVALIDDATA;

     }
 

     ctx->mb_width  = (ctx->width + 15)>> 4;

     ctx->mb_height = AV_RB16(buf + 0x16c);

     if ((ctx->height + 15) >> 4 == ctx->mb_height && frame->interlaced_frame)

         ctx->height <<= 1;
 

     av_log(ctx->avctx, AV_LOG_VERBOSE, "%dx%d, 4:%s %d bits, MBAFF=%d ACT=%d\n",
            ctx->width, ctx->height, ctx->is_444 ? "4:4" : "2:2",
            ctx->bit_depth, ctx->mbaff, ctx->act);
 

     // Newer format supports variable mb_scan_index sizes

     if (ctx->mb_height > 68 && ff_dnxhd_check_header_prefix_hr(header_prefix)) {

         ctx->data_offset = 0x170 + (ctx->mb_height << 2);
     } else {

         if (ctx->mb_height > 68) {

             av_log(ctx->avctx, AV_LOG_ERROR,
                    "mb height too big: %d\n", ctx->mb_height);
             return AVERROR_INVALIDDATA;
         }
         ctx->data_offset = 0x280;
     }

     if ((ctx->mb_height << frame->interlaced_frame) > (ctx->height + 15) >> 4) {
         av_log(ctx->avctx, AV_LOG_ERROR,
                 "mb height too big: %d\n", ctx->mb_height);
         return AVERROR_INVALIDDATA;
     }

 
     if (buf_size < ctx->data_offset) {

         av_log(ctx->avctx, AV_LOG_ERROR,

                "buffer too small (%d < %d).\n", buf_size, ctx->data_offset);

         return AVERROR_INVALIDDATA;

     }
 

     if (ctx->mb_height > FF_ARRAY_ELEMS(ctx->mb_scan_index)) {
         av_log(ctx->avctx, AV_LOG_ERROR,

                "mb_height too big (%d > %"SIZE_SPECIFIER").\n", ctx->mb_height, FF_ARRAY_ELEMS(ctx->mb_scan_index));

         return AVERROR_INVALIDDATA;
     }

     for (i = 0; i < ctx->mb_height; i++) {

         ctx->mb_scan_index[i] = AV_RB32(buf + 0x170 + (i << 2));

         ff_dlog(ctx->avctx, "mb scan index %d, pos %d: %"PRIu32"\n",
                 i, 0x170 + (i << 2), ctx->mb_scan_index[i]);

         if (buf_size - ctx->data_offset < ctx->mb_scan_index[i]) {

             av_log(ctx->avctx, AV_LOG_ERROR,

                    "invalid mb scan index (%"PRIu32" vs %u).\n",

                    ctx->mb_scan_index[i], buf_size - ctx->data_offset);

             return AVERROR_INVALIDDATA;

         }
     }
 
     return 0;
 }
 

 static av_always_inline int dnxhd_decode_dct_block(const DNXHDContext *ctx,

                                                    RowContext *row,
                                                    int n,
                                                    int index_bits,
                                                    int level_bias,

                                                    int level_shift,
                                                    int dc_shift)

 {

     int i, j, index1, index2, len, flags;

     int level, component, sign;

     const int *scale;

     const uint8_t *weight_matrix;

     const uint8_t *ac_info = ctx->cid_table->ac_info;

     int16_t *block = row->blocks[n];

     const int eob_index     = ctx->cid_table->eob_index;

     int ret = 0;

     OPEN_READER(bs, &row->gb);

     ctx->bdsp.clear_block(block);
 

     if (!ctx->is_444) {

         if (n & 2) {
             component     = 1 + (n & 1);

             scale = row->chroma_scale;

             weight_matrix = ctx->cid_table->chroma_weight;
         } else {

             component     = 0;

             scale = row->luma_scale;

             weight_matrix = ctx->cid_table->luma_weight;
         }

     } else {

         component = (n >> 1) % 3;
         if (component) {

             scale = row->chroma_scale;

             weight_matrix = ctx->cid_table->chroma_weight;
         } else {

             scale = row->luma_scale;

             weight_matrix = ctx->cid_table->luma_weight;
         }

     }
 

     UPDATE_CACHE(bs, &row->gb);
     GET_VLC(len, bs, &row->gb, ctx->dc_vlc.table, DNXHD_DC_VLC_BITS, 1);

     if (len) {

         level = GET_CACHE(bs, &row->gb);
         LAST_SKIP_BITS(bs, &row->gb, len);

         sign  = ~level >> 31;
         level = (NEG_USR32(sign ^ level, len) ^ sign) - sign;

         row->last_dc[component] += level * (1 << dc_shift);

     }

     block[0] = row->last_dc[component];

     i = 0;

     UPDATE_CACHE(bs, &row->gb);
     GET_VLC(index1, bs, &row->gb, ctx->ac_vlc.table,

             DNXHD_VLC_BITS, 2);
 

     while (index1 != eob_index) {

         level = ac_info[2*index1+0];
         flags = ac_info[2*index1+1];

         sign = SHOW_SBITS(bs, &row->gb, 1);
         SKIP_BITS(bs, &row->gb, 1);

         if (flags & 1) {

             level += SHOW_UBITS(bs, &row->gb, index_bits) << 7;
             SKIP_BITS(bs, &row->gb, index_bits);

         }
 

         if (flags & 2) {

             UPDATE_CACHE(bs, &row->gb);
             GET_VLC(index2, bs, &row->gb, ctx->run_vlc.table,

                     DNXHD_VLC_BITS, 2);

             i += ctx->cid_table->run[index2];

         }
 

         if (++i > 63) {

             av_log(ctx->avctx, AV_LOG_ERROR, "ac tex damaged %d, %d\n", n, i);

             ret = -1;

             break;

         }
 

         j     = ctx->scantable.permutated[i];

         level *= scale[i];

         level += scale[i] >> 1;

         if (level_bias < 32 || weight_matrix[i] != level_bias)

             level += level_bias; // 1<<(level_shift-1)

         level >>= level_shift;
 

         block[j] = (level ^ sign) - sign;

         UPDATE_CACHE(bs, &row->gb);
         GET_VLC(index1, bs, &row->gb, ctx->ac_vlc.table,

                 DNXHD_VLC_BITS, 2);

     }

     CLOSE_READER(bs, &row->gb);

     return ret;

 }
 

 static int dnxhd_decode_dct_block_8(const DNXHDContext *ctx,

                                     RowContext *row, int n)

 {

     return dnxhd_decode_dct_block(ctx, row, n, 4, 32, 6, 0);

 }
 

 static int dnxhd_decode_dct_block_10(const DNXHDContext *ctx,

                                      RowContext *row, int n)

 {

     return dnxhd_decode_dct_block(ctx, row, n, 6, 8, 4, 0);

 }
 

 static int dnxhd_decode_dct_block_10_444(const DNXHDContext *ctx,

                                          RowContext *row, int n)

 {

     return dnxhd_decode_dct_block(ctx, row, n, 6, 32, 6, 0);
 }
 
 static int dnxhd_decode_dct_block_12(const DNXHDContext *ctx,
                                      RowContext *row, int n)
 {
     return dnxhd_decode_dct_block(ctx, row, n, 6, 8, 4, 2);
 }
 
 static int dnxhd_decode_dct_block_12_444(const DNXHDContext *ctx,
                                          RowContext *row, int n)
 {
     return dnxhd_decode_dct_block(ctx, row, n, 6, 32, 4, 2);

 }
 

 static int dnxhd_decode_macroblock(const DNXHDContext *ctx, RowContext *row,
                                    AVFrame *frame, int x, int y)

 {

     int shift1 = ctx->bit_depth >= 10;

     int dct_linesize_luma   = frame->linesize[0];
     int dct_linesize_chroma = frame->linesize[1];

     uint8_t *dest_y, *dest_u, *dest_v;

     int dct_y_offset, dct_x_offset;

     int qscale, i, act;

     int interlaced_mb = 0;

     if (ctx->mbaff) {

         interlaced_mb = get_bits1(&row->gb);
         qscale = get_bits(&row->gb, 10);

     } else {

         qscale = get_bits(&row->gb, 11);

     }

     act = get_bits1(&row->gb);

     if (act) {

         if (!ctx->act) {
             static int act_warned;
             if (!act_warned) {
                 act_warned = 1;
                 av_log(ctx->avctx, AV_LOG_ERROR,
                        "ACT flag set, in violation of frame header.\n");
             }
         } else if (row->format == -1) {
             row->format = act;
         } else if (row->format != act) {
             row->format = 2; // Variable

         }
     }

     if (qscale != row->last_qscale) {

         for (i = 0; i < 64; i++) {

             row->luma_scale[i]   = qscale * ctx->cid_table->luma_weight[i];
             row->chroma_scale[i] = qscale * ctx->cid_table->chroma_weight[i];

         }

         row->last_qscale = qscale;

     }
 

     for (i = 0; i < 8 + 4 * ctx->is_444; i++) {

         if (ctx->decode_dct_block(ctx, row, i) < 0)
             return AVERROR_INVALIDDATA;

     }

     if (frame->interlaced_frame) {

         dct_linesize_luma   <<= 1;
         dct_linesize_chroma <<= 1;
     }
 

     dest_y = frame->data[0] + ((y * dct_linesize_luma)   << 4) + (x << (4 + shift1));

     dest_u = frame->data[1] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1 + ctx->is_444));
     dest_v = frame->data[2] + ((y * dct_linesize_chroma) << 4) + (x << (3 + shift1 + ctx->is_444));

     if (frame->interlaced_frame && ctx->cur_field) {

         dest_y += frame->linesize[0];
         dest_u += frame->linesize[1];
         dest_v += frame->linesize[2];

     }

     if (interlaced_mb) {
         dct_linesize_luma   <<= 1;
         dct_linesize_chroma <<= 1;
     }

     dct_y_offset = interlaced_mb ? frame->linesize[0] : (dct_linesize_luma << 3);

     dct_x_offset = 8 << shift1;

     if (!ctx->is_444) {

         ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, row->blocks[0]);
         ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, row->blocks[1]);
         ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, row->blocks[4]);
         ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, row->blocks[5]);

         if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {

             dct_y_offset = interlaced_mb ? frame->linesize[1] : (dct_linesize_chroma << 3);

             ctx->idsp.idct_put(dest_u,                dct_linesize_chroma, row->blocks[2]);
             ctx->idsp.idct_put(dest_v,                dct_linesize_chroma, row->blocks[3]);
             ctx->idsp.idct_put(dest_u + dct_y_offset, dct_linesize_chroma, row->blocks[6]);
             ctx->idsp.idct_put(dest_v + dct_y_offset, dct_linesize_chroma, row->blocks[7]);

         }
     } else {

         ctx->idsp.idct_put(dest_y,                               dct_linesize_luma, row->blocks[0]);
         ctx->idsp.idct_put(dest_y + dct_x_offset,                dct_linesize_luma, row->blocks[1]);
         ctx->idsp.idct_put(dest_y + dct_y_offset,                dct_linesize_luma, row->blocks[6]);
         ctx->idsp.idct_put(dest_y + dct_y_offset + dct_x_offset, dct_linesize_luma, row->blocks[7]);

         if (!(ctx->avctx->flags & AV_CODEC_FLAG_GRAY)) {

             dct_y_offset = interlaced_mb ? frame->linesize[1] : (dct_linesize_chroma << 3);

             ctx->idsp.idct_put(dest_u,                               dct_linesize_chroma, row->blocks[2]);
             ctx->idsp.idct_put(dest_u + dct_x_offset,                dct_linesize_chroma, row->blocks[3]);
             ctx->idsp.idct_put(dest_u + dct_y_offset,                dct_linesize_chroma, row->blocks[8]);
             ctx->idsp.idct_put(dest_u + dct_y_offset + dct_x_offset, dct_linesize_chroma, row->blocks[9]);
             ctx->idsp.idct_put(dest_v,                               dct_linesize_chroma, row->blocks[4]);
             ctx->idsp.idct_put(dest_v + dct_x_offset,                dct_linesize_chroma, row->blocks[5]);
             ctx->idsp.idct_put(dest_v + dct_y_offset,                dct_linesize_chroma, row->blocks[10]);
             ctx->idsp.idct_put(dest_v + dct_y_offset + dct_x_offset, dct_linesize_chroma, row->blocks[11]);

         }

     }
 
     return 0;
 }
 

 static int dnxhd_decode_row(AVCodecContext *avctx, void *data,
                             int rownb, int threadnb)

 {

     const DNXHDContext *ctx = avctx->priv_data;
     uint32_t offset = ctx->mb_scan_index[rownb];
     RowContext *row = ctx->rows + threadnb;
     int x;
 
     row->last_dc[0] =
     row->last_dc[1] =
     row->last_dc[2] = 1 << (ctx->bit_depth + 2); // for levels +2^(bitdepth-1)
     init_get_bits(&row->gb, ctx->buf + offset, (ctx->buf_size - offset) << 3);
     for (x = 0; x < ctx->mb_width; x++) {
         //START_TIMER;

         int ret = dnxhd_decode_macroblock(ctx, row, data, x, rownb);
         if (ret < 0) {
             row->errors++;
             return ret;
         }

         //STOP_TIMER("decode macroblock");

     }

     return 0;
 }
 

 static int dnxhd_decode_frame(AVCodecContext *avctx, void *data,
                               int *got_frame, AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     DNXHDContext *ctx = avctx->priv_data;

     ThreadFrame frame = { .f = data };

     AVFrame *picture = data;

     int first_field = 1;

     int ret, i;

     ff_dlog(avctx, "frame size %d\n", buf_size);

     for (i = 0; i < avctx->thread_count; i++)
         ctx->rows[i].format = -1;
 

 decode_coding_unit:

     if ((ret = dnxhd_decode_header(ctx, picture, buf, buf_size, first_field)) < 0)
         return ret;

     if ((avctx->width || avctx->height) &&
         (ctx->width != avctx->width || ctx->height != avctx->height)) {

         av_log(avctx, AV_LOG_WARNING, "frame size changed: %dx%d -> %ux%u\n",

                avctx->width, avctx->height, ctx->width, ctx->height);
         first_field = 1;
     }

     if (avctx->pix_fmt != AV_PIX_FMT_NONE && avctx->pix_fmt != ctx->pix_fmt) {
         av_log(avctx, AV_LOG_WARNING, "pix_fmt changed: %s -> %s\n",
                av_get_pix_fmt_name(avctx->pix_fmt), av_get_pix_fmt_name(ctx->pix_fmt));
         first_field = 1;
     }

     avctx->pix_fmt = ctx->pix_fmt;

     ret = ff_set_dimensions(avctx, ctx->width, ctx->height);
     if (ret < 0)
         return ret;

     if (first_field) {

         if ((ret = ff_thread_get_buffer(avctx, &frame, 0)) < 0)

             return ret;

         picture->pict_type = AV_PICTURE_TYPE_I;
         picture->key_frame = 1;

     }

     ctx->buf_size = buf_size - ctx->data_offset;
     ctx->buf = buf + ctx->data_offset;

     avctx->execute2(avctx, dnxhd_decode_row, picture, NULL, ctx->mb_height);

     if (first_field && picture->interlaced_frame) {

         buf      += ctx->cid_table->coding_unit_size;
         buf_size -= ctx->cid_table->coding_unit_size;
         first_field = 0;
         goto decode_coding_unit;
     }
 

     ret = 0;
     for (i = 0; i < avctx->thread_count; i++) {
         ret += ctx->rows[i].errors;
         ctx->rows[i].errors = 0;
     }
 

     if (ctx->act) {
         static int act_warned;
         int format = ctx->rows[0].format;
         for (i = 1; i < avctx->thread_count; i++) {
             if (ctx->rows[i].format != format &&
                 ctx->rows[i].format != -1 /* not run */) {
                 format = 2;
                 break;
             }
         }
         switch (format) {
         case -1:
         case 2:
             if (!act_warned) {
                 act_warned = 1;
                 av_log(ctx->avctx, AV_LOG_ERROR,
                        "Unsupported: variable ACT flag.\n");
             }
             break;
         case 0:
             ctx->pix_fmt = ctx->bit_depth==10
                          ? AV_PIX_FMT_GBRP10 : AV_PIX_FMT_GBRP12;
             break;
         case 1:
             ctx->pix_fmt = ctx->bit_depth==10
                          ? AV_PIX_FMT_YUV444P10 : AV_PIX_FMT_YUV444P12;
             break;
         }
     }
     avctx->pix_fmt = ctx->pix_fmt;

     if (ret) {
         av_log(ctx->avctx, AV_LOG_ERROR, "%d lines with errors\n", ret);
         return AVERROR_INVALIDDATA;
     }
 

     *got_frame = 1;

     return avpkt->size;

 }
 

 static av_cold int dnxhd_decode_close(AVCodecContext *avctx)

 {
     DNXHDContext *ctx = avctx->priv_data;
 

     ff_free_vlc(&ctx->ac_vlc);
     ff_free_vlc(&ctx->dc_vlc);
     ff_free_vlc(&ctx->run_vlc);

 
     av_freep(&ctx->rows);
 

     return 0;
 }
 

 AVCodec ff_dnxhd_decoder = {

     .name           = "dnxhd",

     .long_name      = NULL_IF_CONFIG_SMALL("VC3/DNxHD"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_DNXHD,

     .priv_data_size = sizeof(DNXHDContext),
     .init           = dnxhd_decode_init,
     .close          = dnxhd_decode_close,
     .decode         = dnxhd_decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS |
                       AV_CODEC_CAP_SLICE_THREADS,
     .init_thread_copy = ONLY_IF_THREADS_ENABLED(dnxhd_decode_init_thread_copy),

     .profiles       = NULL_IF_CONFIG_SMALL(ff_dnxhd_profiles),

 };