/*
  * H.264 HW decode acceleration through VA API
  *
  * Copyright (C) 2008-2009 Splitted-Desktop Systems
  *
  * 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 "h264dec.h"

 #include "h264_ps.h"

 #include "hwaccel.h"

 #include "vaapi_decode.h"

 /**
  * @file

  * This file implements the glue code between FFmpeg's and VA API's

  * structures for H.264 decoding.

  */
 
 /**

  * Initialize an empty VA API picture.

  *
  * VA API requires a fixed-size reference picture array.
  */
 static void init_vaapi_pic(VAPictureH264 *va_pic)
 {
     va_pic->picture_id          = VA_INVALID_ID;
     va_pic->flags               = VA_PICTURE_H264_INVALID;
     va_pic->TopFieldOrderCnt    = 0;
     va_pic->BottomFieldOrderCnt = 0;
 }
 
 /**

  * Translate an FFmpeg Picture into its VA API form.

  *
  * @param[out] va_pic          A pointer to VA API's own picture struct
  * @param[in]  pic             A pointer to the FFmpeg picture struct to convert
  * @param[in]  pic_structure   The picture field type (as defined in mpegvideo.h),
  *                             supersedes pic's field type if nonzero.
  */
 static void fill_vaapi_pic(VAPictureH264 *va_pic,

                            const H264Picture *pic,

                            int            pic_structure)
 {
     if (pic_structure == 0)

         pic_structure = pic->reference;

     pic_structure &= PICT_FRAME; /* PICT_TOP_FIELD|PICT_BOTTOM_FIELD */

     va_pic->picture_id = ff_vaapi_get_surface_id(pic->f);

     va_pic->frame_idx  = pic->long_ref ? pic->pic_id : pic->frame_num;
 
     va_pic->flags      = 0;
     if (pic_structure != PICT_FRAME)
         va_pic->flags |= (pic_structure & PICT_TOP_FIELD) ? VA_PICTURE_H264_TOP_FIELD : VA_PICTURE_H264_BOTTOM_FIELD;

     if (pic->reference)

         va_pic->flags |= pic->long_ref ? VA_PICTURE_H264_LONG_TERM_REFERENCE : VA_PICTURE_H264_SHORT_TERM_REFERENCE;
 
     va_pic->TopFieldOrderCnt = 0;
     if (pic->field_poc[0] != INT_MAX)
         va_pic->TopFieldOrderCnt = pic->field_poc[0];
 
     va_pic->BottomFieldOrderCnt = 0;
     if (pic->field_poc[1] != INT_MAX)
         va_pic->BottomFieldOrderCnt = pic->field_poc[1];
 }
 
 /** Decoded Picture Buffer (DPB). */
 typedef struct DPB {
     int            size;        ///< Current number of reference frames in the DPB
     int            max_size;    ///< Max number of reference frames. This is FF_ARRAY_ELEMS(VAPictureParameterBufferH264.ReferenceFrames)
     VAPictureH264 *va_pics;     ///< Pointer to VAPictureParameterBufferH264.ReferenceFrames array
 } DPB;
 
 /**

  * Append picture to the decoded picture buffer, in a VA API form that

  * merges the second field picture attributes with the first, if
  * available.  The decoded picture buffer's size must be large enough
  * to receive the new VA API picture object.
  */

 static int dpb_add(DPB *dpb, const H264Picture *pic)

 {
     int i;
 
     if (dpb->size >= dpb->max_size)
         return -1;
 
     for (i = 0; i < dpb->size; i++) {
         VAPictureH264 * const va_pic = &dpb->va_pics[i];

         if (va_pic->picture_id == ff_vaapi_get_surface_id(pic->f)) {

             VAPictureH264 temp_va_pic;
             fill_vaapi_pic(&temp_va_pic, pic, 0);
 
             if ((temp_va_pic.flags ^ va_pic->flags) & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD)) {
                 va_pic->flags |= temp_va_pic.flags & (VA_PICTURE_H264_TOP_FIELD | VA_PICTURE_H264_BOTTOM_FIELD);
                 /* Merge second field */
                 if (temp_va_pic.flags & VA_PICTURE_H264_TOP_FIELD) {
                     va_pic->TopFieldOrderCnt    = temp_va_pic.TopFieldOrderCnt;
                 } else {
                     va_pic->BottomFieldOrderCnt = temp_va_pic.BottomFieldOrderCnt;
                 }
             }
             return 0;
         }
     }
 
     fill_vaapi_pic(&dpb->va_pics[dpb->size++], pic, 0);
     return 0;
 }
 

 /** Fill in VA API reference frames array. */

 static int fill_vaapi_ReferenceFrames(VAPictureParameterBufferH264 *pic_param,

                                       const H264Context            *h)

 {
     DPB dpb;
     int i;
 
     dpb.size     = 0;
     dpb.max_size = FF_ARRAY_ELEMS(pic_param->ReferenceFrames);
     dpb.va_pics  = pic_param->ReferenceFrames;
     for (i = 0; i < dpb.max_size; i++)
         init_vaapi_pic(&dpb.va_pics[i]);
 
     for (i = 0; i < h->short_ref_count; i++) {

         const H264Picture *pic = h->short_ref[i];

         if (pic && pic->reference && dpb_add(&dpb, pic) < 0)

             return -1;
     }
 

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

         const H264Picture *pic = h->long_ref[i];

         if (pic && pic->reference && dpb_add(&dpb, pic) < 0)

             return -1;
     }
     return 0;
 }
 
 /**

  * Fill in VA API reference picture lists from the FFmpeg reference

  * picture list.
  *
  * @param[out] RefPicList  VA API internal reference picture list
  * @param[in]  ref_list    A pointer to the FFmpeg reference list
  * @param[in]  ref_count   The number of reference pictures in ref_list
  */
 static void fill_vaapi_RefPicList(VAPictureH264 RefPicList[32],

                                   const H264Ref *ref_list,

                                   unsigned int  ref_count)
 {
     unsigned int i, n = 0;
     for (i = 0; i < ref_count; i++)

         if (ref_list[i].reference)

             fill_vaapi_pic(&RefPicList[n++], ref_list[i].parent,
                            ref_list[i].reference);

 
     for (; n < 32; n++)
         init_vaapi_pic(&RefPicList[n]);
 }
 
 /**

  * Fill in prediction weight table.

  *
  * VA API requires a plain prediction weight table as it does not infer
  * any value.
  *
  * @param[in]  h                   A pointer to the current H.264 context
  * @param[in]  list                The reference frame list index to use
  * @param[out] luma_weight_flag    VA API plain luma weight flag
  * @param[out] luma_weight         VA API plain luma weight table
  * @param[out] luma_offset         VA API plain luma offset table
  * @param[out] chroma_weight_flag  VA API plain chroma weight flag
  * @param[out] chroma_weight       VA API plain chroma weight table
  * @param[out] chroma_offset       VA API plain chroma offset table
  */

 static void fill_vaapi_plain_pred_weight_table(const H264Context *h,

                                                int            list,
                                                unsigned char *luma_weight_flag,
                                                short          luma_weight[32],
                                                short          luma_offset[32],
                                                unsigned char *chroma_weight_flag,
                                                short          chroma_weight[32][2],
                                                short          chroma_offset[32][2])
 {

     const H264SliceContext *sl = &h->slice_ctx[0];

     unsigned int i, j;
 

     *luma_weight_flag    = sl->pwt.luma_weight_flag[list];
     *chroma_weight_flag  = sl->pwt.chroma_weight_flag[list];

     for (i = 0; i < sl->ref_count[list]; i++) {

         /* VA API also wants the inferred (default) values, not
            only what is available in the bitstream (7.4.3.2). */

         if (sl->pwt.luma_weight_flag[list]) {
             luma_weight[i] = sl->pwt.luma_weight[i][list][0];
             luma_offset[i] = sl->pwt.luma_weight[i][list][1];

         } else {

             luma_weight[i] = 1 << sl->pwt.luma_log2_weight_denom;

             luma_offset[i] = 0;
         }
         for (j = 0; j < 2; j++) {

             if (sl->pwt.chroma_weight_flag[list]) {
                 chroma_weight[i][j] = sl->pwt.chroma_weight[i][list][j][0];
                 chroma_offset[i][j] = sl->pwt.chroma_weight[i][list][j][1];

             } else {

                 chroma_weight[i][j] = 1 << sl->pwt.chroma_log2_weight_denom;

                 chroma_offset[i][j] = 0;
             }
         }
     }
 }
 

 /** Initialize and start decoding a frame with VA API. */

 static int vaapi_h264_start_frame(AVCodecContext          *avctx,
                                   av_unused const uint8_t *buffer,
                                   av_unused uint32_t       size)

 {

     const H264Context *h = avctx->priv_data;

     VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;

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

     VAPictureParameterBufferH264 pic_param;
     VAIQMatrixBufferH264 iq_matrix;
     int err;
 
     pic->output_surface = ff_vaapi_get_surface_id(h->cur_pic_ptr->f);
 
     pic_param = (VAPictureParameterBufferH264) {
         .picture_width_in_mbs_minus1                = h->mb_width - 1,
         .picture_height_in_mbs_minus1               = h->mb_height - 1,
         .bit_depth_luma_minus8                      = sps->bit_depth_luma - 8,
         .bit_depth_chroma_minus8                    = sps->bit_depth_chroma - 8,
         .num_ref_frames                             = sps->ref_frame_count,
         .seq_fields.bits = {
             .chroma_format_idc                      = sps->chroma_format_idc,
             .residual_colour_transform_flag         = sps->residual_color_transform_flag,
             .gaps_in_frame_num_value_allowed_flag   = sps->gaps_in_frame_num_allowed_flag,
             .frame_mbs_only_flag                    = sps->frame_mbs_only_flag,
             .mb_adaptive_frame_field_flag           = sps->mb_aff,
             .direct_8x8_inference_flag              = sps->direct_8x8_inference_flag,
             .MinLumaBiPredSize8x8                   = sps->level_idc >= 31, /* A.3.3.2 */
             .log2_max_frame_num_minus4              = sps->log2_max_frame_num - 4,
             .pic_order_cnt_type                     = sps->poc_type,
             .log2_max_pic_order_cnt_lsb_minus4      = sps->log2_max_poc_lsb - 4,
             .delta_pic_order_always_zero_flag       = sps->delta_pic_order_always_zero_flag,
         },
         .num_slice_groups_minus1                    = pps->slice_group_count - 1,
         .slice_group_map_type                       = pps->mb_slice_group_map_type,
         .slice_group_change_rate_minus1             = 0, /* FMO is not implemented */
         .pic_init_qp_minus26                        = pps->init_qp - 26,
         .pic_init_qs_minus26                        = pps->init_qs - 26,
         .chroma_qp_index_offset                     = pps->chroma_qp_index_offset[0],
         .second_chroma_qp_index_offset              = pps->chroma_qp_index_offset[1],
         .pic_fields.bits = {
             .entropy_coding_mode_flag               = pps->cabac,
             .weighted_pred_flag                     = pps->weighted_pred,
             .weighted_bipred_idc                    = pps->weighted_bipred_idc,
             .transform_8x8_mode_flag                = pps->transform_8x8_mode,
             .field_pic_flag                         = h->picture_structure != PICT_FRAME,
             .constrained_intra_pred_flag            = pps->constrained_intra_pred,
             .pic_order_present_flag                 = pps->pic_order_present,
             .deblocking_filter_control_present_flag = pps->deblocking_filter_parameters_present,
             .redundant_pic_cnt_present_flag         = pps->redundant_pic_cnt_present,
             .reference_pic_flag                     = h->nal_ref_idc != 0,
         },
         .frame_num                                  = h->poc.frame_num,
     };
 
     fill_vaapi_pic(&pic_param.CurrPic, h->cur_pic_ptr, h->picture_structure);
     err = fill_vaapi_ReferenceFrames(&pic_param, h);
     if (err < 0)
         goto fail;
 
     err = ff_vaapi_decode_make_param_buffer(avctx, pic,
                                             VAPictureParameterBufferType,
                                             &pic_param, sizeof(pic_param));
     if (err < 0)
         goto fail;
 
     memcpy(iq_matrix.ScalingList4x4,
            pps->scaling_matrix4, sizeof(iq_matrix.ScalingList4x4));
     memcpy(iq_matrix.ScalingList8x8[0],
            pps->scaling_matrix8[0], sizeof(iq_matrix.ScalingList8x8[0]));
     memcpy(iq_matrix.ScalingList8x8[1],
            pps->scaling_matrix8[3], sizeof(iq_matrix.ScalingList8x8[0]));
 
     err = ff_vaapi_decode_make_param_buffer(avctx, pic,
                                             VAIQMatrixBufferType,
                                             &iq_matrix, sizeof(iq_matrix));
     if (err < 0)
         goto fail;

 
     return 0;

 
 fail:
     ff_vaapi_decode_cancel(avctx, pic);
     return err;

 }
 

 /** End a hardware decoding based frame. */

 static int vaapi_h264_end_frame(AVCodecContext *avctx)

 {

     const H264Context *h = avctx->priv_data;

     VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;

     H264SliceContext *sl = &h->slice_ctx[0];

     int ret;

     ret = ff_vaapi_decode_issue(avctx, pic);

     if (ret < 0)
         goto finish;
 

     ff_h264_draw_horiz_band(h, sl, 0, h->avctx->height);

 
 finish:
     return ret;

 }
 

 /** Decode the given H.264 slice with VA API. */

 static int vaapi_h264_decode_slice(AVCodecContext *avctx,
                                    const uint8_t  *buffer,
                                    uint32_t        size)

 {

     const H264Context *h = avctx->priv_data;

     VAAPIDecodePicture *pic = h->cur_pic_ptr->hwaccel_picture_private;

     const H264SliceContext *sl  = &h->slice_ctx[0];

     VASliceParameterBufferH264 slice_param;
     int err;
 
     slice_param = (VASliceParameterBufferH264) {
         .slice_data_size               = size,
         .slice_data_offset             = 0,
         .slice_data_flag               = VA_SLICE_DATA_FLAG_ALL,
         .slice_data_bit_offset         = get_bits_count(&sl->gb),
         .first_mb_in_slice             = (sl->mb_y >> FIELD_OR_MBAFF_PICTURE(h)) * h->mb_width + sl->mb_x,
         .slice_type                    = ff_h264_get_slice_type(sl),
         .direct_spatial_mv_pred_flag   = sl->slice_type == AV_PICTURE_TYPE_B ? sl->direct_spatial_mv_pred : 0,
         .num_ref_idx_l0_active_minus1  = sl->list_count > 0 ? sl->ref_count[0] - 1 : 0,
         .num_ref_idx_l1_active_minus1  = sl->list_count > 1 ? sl->ref_count[1] - 1 : 0,
         .cabac_init_idc                = sl->cabac_init_idc,
         .slice_qp_delta                = sl->qscale - h->ps.pps->init_qp,
         .disable_deblocking_filter_idc = sl->deblocking_filter < 2 ? !sl->deblocking_filter : sl->deblocking_filter,
         .slice_alpha_c0_offset_div2    = sl->slice_alpha_c0_offset / 2,
         .slice_beta_offset_div2        = sl->slice_beta_offset     / 2,
         .luma_log2_weight_denom        = sl->pwt.luma_log2_weight_denom,
         .chroma_log2_weight_denom      = sl->pwt.chroma_log2_weight_denom,
     };
 
     fill_vaapi_RefPicList(slice_param.RefPicList0, sl->ref_list[0],
                           sl->list_count > 0 ? sl->ref_count[0] : 0);
     fill_vaapi_RefPicList(slice_param.RefPicList1, sl->ref_list[1],
                           sl->list_count > 1 ? sl->ref_count[1] : 0);

 
     fill_vaapi_plain_pred_weight_table(h, 0,

                                        &slice_param.luma_weight_l0_flag,
                                        slice_param.luma_weight_l0,
                                        slice_param.luma_offset_l0,
                                        &slice_param.chroma_weight_l0_flag,
                                        slice_param.chroma_weight_l0,
                                        slice_param.chroma_offset_l0);

     fill_vaapi_plain_pred_weight_table(h, 1,

                                        &slice_param.luma_weight_l1_flag,
                                        slice_param.luma_weight_l1,
                                        slice_param.luma_offset_l1,
                                        &slice_param.chroma_weight_l1_flag,
                                        slice_param.chroma_weight_l1,
                                        slice_param.chroma_offset_l1);
 
     err = ff_vaapi_decode_make_slice_buffer(avctx, pic,
                                             &slice_param, sizeof(slice_param),
                                             buffer, size);
     if (err) {
         ff_vaapi_decode_cancel(avctx, pic);
         return err;
     }
 

     return 0;
 }
 

 const AVHWAccel ff_h264_vaapi_hwaccel = {

     .name                 = "h264_vaapi",
     .type                 = AVMEDIA_TYPE_VIDEO,
     .id                   = AV_CODEC_ID_H264,
     .pix_fmt              = AV_PIX_FMT_VAAPI,
     .start_frame          = &vaapi_h264_start_frame,
     .end_frame            = &vaapi_h264_end_frame,
     .decode_slice         = &vaapi_h264_decode_slice,
     .frame_priv_data_size = sizeof(VAAPIDecodePicture),
     .init                 = &ff_vaapi_decode_init,
     .uninit               = &ff_vaapi_decode_uninit,

     .frame_params         = &ff_vaapi_common_frame_params,

     .priv_data_size       = sizeof(VAAPIDecodeContext),

     .caps_internal        = HWACCEL_CAP_ASYNC_SAFE,

 };