text: /*
   * MPEG-2 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 "vaapi_internal.h"
  
  /** Reconstruct bitstream f_code */
  static inline int mpeg2_get_f_code(MpegEncContext *s)
  {
      return (s->mpeg_f_code[0][0] << 12) | (s->mpeg_f_code[0][1] << 8) |
             (s->mpeg_f_code[1][0] <<  4) |  s->mpeg_f_code[1][1];
  }
  
  /** Determine frame start: first field for field picture or frame picture */
  static inline int mpeg2_get_is_frame_start(MpegEncContext *s)
  {
      return s->first_field || s->picture_structure == PICT_FRAME;
  }
  
  static int vaapi_mpeg2_start_frame(AVCodecContext *avctx, av_unused const uint8_t *buffer, av_unused uint32_t size)
  {
      struct MpegEncContext * const s = avctx->priv_data;
      struct vaapi_context * const vactx = avctx->hwaccel_context;
      VAPictureParameterBufferMPEG2 *pic_param;
      VAIQMatrixBufferMPEG2 *iq_matrix;
      int i;
  
      av_dlog(avctx, "vaapi_mpeg2_start_frame()\n");
  
      vactx->slice_param_size = sizeof(VASliceParameterBufferMPEG2);
  
      /* Fill in VAPictureParameterBufferMPEG2 */
      pic_param = ff_vaapi_alloc_pic_param(vactx, sizeof(VAPictureParameterBufferMPEG2));
      if (!pic_param)
          return -1;
      pic_param->horizontal_size                                  = s->width;
      pic_param->vertical_size                                    = s->height;
      pic_param->forward_reference_picture                        = VA_INVALID_ID;
      pic_param->backward_reference_picture                       = VA_INVALID_ID;
      pic_param->picture_coding_type                              = s->pict_type;
      pic_param->f_code                                           = mpeg2_get_f_code(s);
      pic_param->picture_coding_extension.value                   = 0; /* reset all bits */
      pic_param->picture_coding_extension.bits.intra_dc_precision = s->intra_dc_precision;
      pic_param->picture_coding_extension.bits.picture_structure  = s->picture_structure;
      pic_param->picture_coding_extension.bits.top_field_first    = s->top_field_first;
      pic_param->picture_coding_extension.bits.frame_pred_frame_dct = s->frame_pred_frame_dct;
      pic_param->picture_coding_extension.bits.concealment_motion_vectors = s->concealment_motion_vectors;
      pic_param->picture_coding_extension.bits.q_scale_type       = s->q_scale_type;
      pic_param->picture_coding_extension.bits.intra_vlc_format   = s->intra_vlc_format;
      pic_param->picture_coding_extension.bits.alternate_scan     = s->alternate_scan;
      pic_param->picture_coding_extension.bits.repeat_first_field = s->repeat_first_field;
      pic_param->picture_coding_extension.bits.progressive_frame  = s->progressive_frame;
      pic_param->picture_coding_extension.bits.is_first_field     = mpeg2_get_is_frame_start(s);
  
      switch (s->pict_type) {
      case AV_PICTURE_TYPE_B:
          pic_param->backward_reference_picture = ff_vaapi_get_surface_id(&s->next_picture);
          // fall-through
      case AV_PICTURE_TYPE_P:
          pic_param->forward_reference_picture = ff_vaapi_get_surface_id(&s->last_picture);
          break;
      }
  
      /* Fill in VAIQMatrixBufferMPEG2 */
      iq_matrix = ff_vaapi_alloc_iq_matrix(vactx, sizeof(VAIQMatrixBufferMPEG2));
      if (!iq_matrix)
          return -1;
      iq_matrix->load_intra_quantiser_matrix              = 1;
      iq_matrix->load_non_intra_quantiser_matrix          = 1;
      iq_matrix->load_chroma_intra_quantiser_matrix       = 1;
      iq_matrix->load_chroma_non_intra_quantiser_matrix   = 1;
  
      for (i = 0; i < 64; i++) {
          int n = s->dsp.idct_permutation[ff_zigzag_direct[i]];
          iq_matrix->intra_quantiser_matrix[i]            = s->intra_matrix[n];
          iq_matrix->non_intra_quantiser_matrix[i]        = s->inter_matrix[n];
          iq_matrix->chroma_intra_quantiser_matrix[i]     = s->chroma_intra_matrix[n];
          iq_matrix->chroma_non_intra_quantiser_matrix[i] = s->chroma_inter_matrix[n];
      }
      return 0;
  }
  
  static int vaapi_mpeg2_decode_slice(AVCodecContext *avctx, const uint8_t *buffer, uint32_t size)
  {
      MpegEncContext * const s = avctx->priv_data;
      VASliceParameterBufferMPEG2 *slice_param;
      GetBitContext gb;
      uint32_t quantiser_scale_code, intra_slice_flag, macroblock_offset;
  
      av_dlog(avctx, "vaapi_mpeg2_decode_slice(): buffer %p, size %d\n", buffer, size);
  
      /* Determine macroblock_offset */
      init_get_bits(&gb, buffer, 8 * size);
      if (get_bits_long(&gb, 32) >> 8 != 1) /* start code */
          return AVERROR_INVALIDDATA;
      quantiser_scale_code = get_bits(&gb, 5);
      intra_slice_flag = get_bits1(&gb);
      if (intra_slice_flag) {
          skip_bits(&gb, 8);
          if (skip_1stop_8data_bits(&gb) < 0)
              return AVERROR_INVALIDDATA;
      }
      macroblock_offset = get_bits_count(&gb);
  
      /* Fill in VASliceParameterBufferMPEG2 */
      slice_param = (VASliceParameterBufferMPEG2 *)ff_vaapi_alloc_slice(avctx->hwaccel_context, buffer, size);
      if (!slice_param)
          return -1;
      slice_param->macroblock_offset              = macroblock_offset;
      slice_param->slice_horizontal_position      = s->mb_x;
      slice_param->slice_vertical_position        = s->mb_y >> (s->picture_structure != PICT_FRAME);
      slice_param->quantiser_scale_code           = quantiser_scale_code;
      slice_param->intra_slice_flag               = intra_slice_flag;
      return 0;
  }
  
  AVHWAccel ff_mpeg2_vaapi_hwaccel = {
      .name           = "mpeg2_vaapi",
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_MPEG2VIDEO,
      .pix_fmt        = AV_PIX_FMT_VAAPI_VLD,
      .start_frame    = vaapi_mpeg2_start_frame,
      .end_frame      = ff_vaapi_mpeg_end_frame,
      .decode_slice   = vaapi_mpeg2_decode_slice,
  };
  