svq3.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.10平台上编译为嵌入式图形界面操作系统。

	for (i=0; i < 4; i++) {
	  *(uint32_t *) h->mv_cache[m][scan8[0] - 1 + i*8] = 0;
	}
      }
      if (s->mb_y > 0) {
	memcpy (h->mv_cache[m][scan8[0] - 1*8], s->current_picture.motion_val[m][b_xy - h->b_stride], 4*2*sizeof(int16_t));
	memset (&h->ref_cache[m][scan8[0] - 1*8], (h->intra4x4_pred_mode[mb_xy - s->mb_stride][4] == -1) ? PART_NOT_AVAILABLE : 1, 4);

	if (s->mb_x < (s->mb_width - 1)) {
	  *(uint32_t *) h->mv_cache[m][scan8[0] + 4 - 1*8] = *(uint32_t *) s->current_picture.motion_val[m][b_xy - h->b_stride + 4];
	  h->ref_cache[m][scan8[0] + 4 - 1*8] =
		  (h->intra4x4_pred_mode[mb_xy - s->mb_stride + 1][0] == -1 ||
		   h->intra4x4_pred_mode[mb_xy - s->mb_stride][4] == -1) ? PART_NOT_AVAILABLE : 1;
	}else
	  h->ref_cache[m][scan8[0] + 4 - 1*8] = PART_NOT_AVAILABLE;
	if (s->mb_x > 0) {
	  *(uint32_t *) h->mv_cache[m][scan8[0] - 1 - 1*8] = *(uint32_t *) s->current_picture.motion_val[m][b_xy - h->b_stride - 1];
	  h->ref_cache[m][scan8[0] - 1 - 1*8] = (h->intra4x4_pred_mode[mb_xy - s->mb_stride - 1][3] == -1) ? PART_NOT_AVAILABLE : 1;
	}else
	  h->ref_cache[m][scan8[0] - 1 - 1*8] = PART_NOT_AVAILABLE;
      }else
	memset (&h->ref_cache[m][scan8[0] - 1*8 - 1], PART_NOT_AVAILABLE, 8);

      if (s->pict_type != B_TYPE)
	break;
    }

    /* decode motion vector(s) and form prediction(s) */
    if (s->pict_type == P_TYPE) {
      svq3_mc_dir (h, (mb_type - 1), mode, 0, 0);
    } else {	/* B_TYPE */
      if (mb_type != 2) {
	svq3_mc_dir (h, 0, mode, 0, 0);
      } else {
	for (i=0; i < 4; i++) {
	  memset (s->current_picture.motion_val[0][b_xy + i*h->b_stride], 0, 4*2*sizeof(int16_t));
	}
      }
      if (mb_type != 1) {
	svq3_mc_dir (h, 0, mode, 1, (mb_type == 3));
      } else {
	for (i=0; i < 4; i++) {
	  memset (s->current_picture.motion_val[1][b_xy + i*h->b_stride], 0, 4*2*sizeof(int16_t));
	}
      }
    }

    mb_type = MB_TYPE_16x16;
  } else if (mb_type == 8 || mb_type == 33) {	/* INTRA4x4 */
    memset (h->intra4x4_pred_mode_cache, -1, 8*5*sizeof(int8_t));

    if (mb_type == 8) {
      if (s->mb_x > 0) {
	for (i=0; i < 4; i++) {
	  h->intra4x4_pred_mode_cache[scan8[0] - 1 + i*8] = h->intra4x4_pred_mode[mb_xy - 1][i];
	}
	if (h->intra4x4_pred_mode_cache[scan8[0] - 1] == -1) {
	  h->left_samples_available = 0x5F5F;
	}
      }
      if (s->mb_y > 0) {
	h->intra4x4_pred_mode_cache[4+8*0] = h->intra4x4_pred_mode[mb_xy - s->mb_stride][4];
	h->intra4x4_pred_mode_cache[5+8*0] = h->intra4x4_pred_mode[mb_xy - s->mb_stride][5];
	h->intra4x4_pred_mode_cache[6+8*0] = h->intra4x4_pred_mode[mb_xy - s->mb_stride][6];
	h->intra4x4_pred_mode_cache[7+8*0] = h->intra4x4_pred_mode[mb_xy - s->mb_stride][3];

	if (h->intra4x4_pred_mode_cache[4+8*0] == -1) {
	  h->top_samples_available = 0x33FF;
	}
      }

      /* decode prediction codes for luma blocks */
      for (i=0; i < 16; i+=2) {
	vlc = svq3_get_ue_golomb (&s->gb);

	if (vlc >= 25)
	  return -1;

	left	= &h->intra4x4_pred_mode_cache[scan8[i] - 1];
	top	= &h->intra4x4_pred_mode_cache[scan8[i] - 8];

	left[1]	= svq3_pred_1[top[0] + 1][left[0] + 1][svq3_pred_0[vlc][0]];
	left[2]	= svq3_pred_1[top[1] + 1][left[1] + 1][svq3_pred_0[vlc][1]];

	if (left[1] == -1 || left[2] == -1)
	  return -1;
      }
    } else {	/* mb_type == 33, DC_128_PRED block type */
      for (i=0; i < 4; i++) {
	memset (&h->intra4x4_pred_mode_cache[scan8[0] + 8*i], DC_PRED, 4);
      }
    }

    write_back_intra_pred_mode (h);

    if (mb_type == 8) {
      check_intra4x4_pred_mode (h);

      h->top_samples_available  = (s->mb_y == 0) ? 0x33FF : 0xFFFF;
      h->left_samples_available = (s->mb_x == 0) ? 0x5F5F : 0xFFFF;
    } else {
      for (i=0; i < 4; i++) {
        memset (&h->intra4x4_pred_mode_cache[scan8[0] + 8*i], DC_128_PRED, 4);
      }

      h->top_samples_available  = 0x33FF;
      h->left_samples_available = 0x5F5F;
    }

    mb_type = MB_TYPE_INTRA4x4;
  } else {			/* INTRA16x16 */
    dir = i_mb_type_info[mb_type - 8].pred_mode;
    dir = (dir >> 1) ^ 3*(dir & 1) ^ 1;

    if ((h->intra16x16_pred_mode = check_intra_pred_mode (h, dir)) == -1)
      return -1;

    cbp = i_mb_type_info[mb_type - 8].cbp;
    mb_type = MB_TYPE_INTRA16x16;
  }

  if (!IS_INTER(mb_type) && s->pict_type != I_TYPE) {
    for (i=0; i < 4; i++) {
      memset (s->current_picture.motion_val[0][b_xy + i*h->b_stride], 0, 4*2*sizeof(int16_t));
    }
    if (s->pict_type == B_TYPE) {
      for (i=0; i < 4; i++) {
	memset (s->current_picture.motion_val[1][b_xy + i*h->b_stride], 0, 4*2*sizeof(int16_t));
      }
    }
  }
  if (!IS_INTRA4x4(mb_type)) {
    memset (h->intra4x4_pred_mode[mb_xy], DC_PRED, 8);
  }
  if (!IS_SKIP(mb_type) || s->pict_type == B_TYPE) {
    memset (h->non_zero_count_cache + 8, 0, 4*9*sizeof(uint8_t));
    s->dsp.clear_blocks(h->mb);
  }

  if (!IS_INTRA16x16(mb_type) && (!IS_SKIP(mb_type) || s->pict_type == B_TYPE)) {
    if ((vlc = svq3_get_ue_golomb (&s->gb)) >= 48)
      return -1;

    cbp = IS_INTRA(mb_type) ? golomb_to_intra4x4_cbp[vlc] : golomb_to_inter_cbp[vlc];
  }
  if (IS_INTRA16x16(mb_type) || (s->pict_type != I_TYPE && s->adaptive_quant && cbp)) {
    s->qscale += svq3_get_se_golomb (&s->gb);

    if (s->qscale > 31)
      return -1;
  }
  if (IS_INTRA16x16(mb_type)) {
    if (svq3_decode_block (&s->gb, h->mb, 0, 0))
      return -1;
  }

  if (cbp) {
    const int index = IS_INTRA16x16(mb_type) ? 1 : 0;
    const int type = ((s->qscale < 24 && IS_INTRA4x4(mb_type)) ? 2 : 1);

    for (i=0; i < 4; i++) {
      if ((cbp & (1 << i))) {
	for (j=0; j < 4; j++) {
	  k = index ? ((j&1) + 2*(i&1) + 2*(j&2) + 4*(i&2)) : (4*i + j);
	  h->non_zero_count_cache[ scan8[k] ] = 1;

	  if (svq3_decode_block (&s->gb, &h->mb[16*k], index, type))
	    return -1;
	}
      }
    }

    if ((cbp & 0x30)) {
      for (i=0; i < 2; ++i) {
	if (svq3_decode_block (&s->gb, &h->mb[16*(16 + 4*i)], 0, 3))
	  return -1;
      }

      if ((cbp & 0x20)) {
	for (i=0; i < 8; i++) {
	  h->non_zero_count_cache[ scan8[16+i] ] = 1;

	  if (svq3_decode_block (&s->gb, &h->mb[16*(16 + i)], 1, 1))
	    return -1;
	}
      }
    }
  }

  s->current_picture.mb_type[mb_xy] = mb_type;

  if (IS_INTRA(mb_type)) {
    h->chroma_pred_mode = check_intra_pred_mode (h, DC_PRED8x8);
  }

  return 0;
}

static int svq3_decode_slice_header (H264Context *h) {
  MpegEncContext *const s = (MpegEncContext *) h;
  const int mb_xy = s->mb_x + s->mb_y*s->mb_stride;
  int i, header;

  header = get_bits (&s->gb, 8);

  if (((header & 0x9F) != 1 && (header & 0x9F) != 2) || (header & 0x60) == 0) {
    /* TODO: what? */
    av_log(h->s.avctx, AV_LOG_ERROR, "unsupported slice header (%02X)\n", header);
    return -1;
  } else {
    int length = (header >> 5) & 3;

    h->next_slice_index = s->gb.index + 8*show_bits (&s->gb, 8*length) + 8*length;

    if (h->next_slice_index > s->gb.size_in_bits)
      return -1;

    s->gb.size_in_bits = h->next_slice_index - 8*(length - 1);
    s->gb.index += 8;

    if (length > 0) {
      memcpy ((uint8_t *) &s->gb.buffer[s->gb.index >> 3],
             &s->gb.buffer[s->gb.size_in_bits >> 3], (length - 1));
    }
  }

  if ((i = svq3_get_ue_golomb (&s->gb)) == INVALID_VLC || i >= 3)
    return -1;

  h->slice_type = golomb_to_pict_type[i];

  if ((header & 0x9F) == 2) {
    i = (s->mb_num < 64) ? 6 : (1 + av_log2 (s->mb_num - 1));
    s->mb_skip_run = get_bits (&s->gb, i) - (s->mb_x + (s->mb_y * s->mb_width));
  } else {
    get_bits1 (&s->gb);
    s->mb_skip_run = 0;
  }

  h->slice_num = get_bits (&s->gb, 8);
  s->qscale = get_bits (&s->gb, 5);
  s->adaptive_quant = get_bits1 (&s->gb);

  /* unknown fields */
  get_bits1 (&s->gb);

  if (h->unknown_svq3_flag) {
    get_bits1 (&s->gb);
  }

  get_bits1 (&s->gb);
  get_bits (&s->gb, 2);

  while (get_bits1 (&s->gb)) {
    get_bits (&s->gb, 8);
  }

  /* reset intra predictors and invalidate motion vector references */
  if (s->mb_x > 0) {
    memset (h->intra4x4_pred_mode[mb_xy - 1], -1, 4*sizeof(int8_t));
    memset (h->intra4x4_pred_mode[mb_xy - s->mb_x], -1, 8*sizeof(int8_t)*s->mb_x);
  }
  if (s->mb_y > 0) {
    memset (h->intra4x4_pred_mode[mb_xy - s->mb_stride], -1, 8*sizeof(int8_t)*(s->mb_width - s->mb_x));

    if (s->mb_x > 0) {
      h->intra4x4_pred_mode[mb_xy - s->mb_stride - 1][3] = -1;
    }
  }

  return 0;
}

static int svq3_decode_frame (AVCodecContext *avctx,
			      void *data, int *data_size,
			      uint8_t *buf, int buf_size) {
  MpegEncContext *const s = avctx->priv_data;
  H264Context *const h = avctx->priv_data;
  int m, mb_type;

  *data_size = 0;

  s->flags = avctx->flags;
  
  if (!s->context_initialized) {
    s->width = avctx->width;
    s->height = avctx->height;
    h->pred4x4[DIAG_DOWN_LEFT_PRED] = pred4x4_down_left_svq3_c;
    h->pred16x16[PLANE_PRED8x8] = pred16x16_plane_svq3_c;
    h->halfpel_flag = 1;
    h->thirdpel_flag = 1;
    h->unknown_svq3_flag = 0;
    h->chroma_qp = 4;

    if (MPV_common_init (s) < 0)
      return -1;

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

    alloc_tables (h);

    if (avctx->extradata && avctx->extradata_size >= 0x64
	&& !memcmp (avctx->extradata, "SVQ3", 4)) {

      GetBitContext gb;

      init_get_bits (&gb, (uint8_t *) avctx->extradata + 0x62,
		     8*(avctx->extradata_size - 0x62));

      /* 'frame size code' and optional 'width, height' */
      if (get_bits (&gb, 3) == 7) {
	get_bits (&gb, 12);
	get_bits (&gb, 12);
      }

      h->halfpel_flag = get_bits1 (&gb);
      h->thirdpel_flag = get_bits1 (&gb);

      /* unknown fields */
      get_bits1 (&gb);
      get_bits1 (&gb);
      get_bits1 (&gb);
      get_bits1 (&gb);

      s->low_delay = get_bits1 (&gb);

      /* unknown field */
      get_bits1 (&gb);

      while (get_bits1 (&gb)) {
	get_bits (&gb, 8);
      }

      h->unknown_svq3_flag = get_bits1 (&gb);
      avctx->has_b_frames = !s->low_delay;
    }
  }

  /* special case for last picture */
  if (buf_size == 0) {
    if (s->next_picture_ptr && !s->low_delay) {
      *(AVFrame *) data = *(AVFrame *) &s->next_picture;
      *data_size = sizeof(AVFrame);
    }
    return 0;
  }

  init_get_bits (&s->gb, buf, 8*buf_size);

  s->mb_x = s->mb_y = 0;

  if (svq3_decode_slice_header (h))
    return -1;

  s->pict_type = h->slice_type;
  s->picture_number = h->slice_num;

  if(avctx->debug&FF_DEBUG_PICT_INFO){
      av_log(h->s.avctx, AV_LOG_DEBUG, "%c hpel:%d, tpel:%d aqp:%d qp:%d\n", 
      av_get_pict_type_char(s->pict_type), h->halfpel_flag, h->thirdpel_flag,
      s->adaptive_quant, s->qscale
      );
  }

  /* for hurry_up==5 */
  s->current_picture.pict_type = s->pict_type;
  s->current_picture.key_frame = (s->pict_type == I_TYPE);

  /* skip b frames if we dont have reference frames */
  if (s->last_picture_ptr == NULL && s->pict_type == B_TYPE) return 0;
  /* skip b frames if we are in a hurry */
  if (avctx->hurry_up && s->pict_type == B_TYPE) return 0;
  /* skip everything if we are in a hurry >= 5 */
  if (avctx->hurry_up >= 5) return 0;

  if (s->next_p_frame_damaged) {
    if (s->pict_type == B_TYPE)
      return 0;
    else
      s->next_p_frame_damaged = 0;
  }

  frame_start (h);

  if (s->pict_type == B_TYPE) {
    h->frame_num_offset = (h->slice_num - h->prev_frame_num);

    if (h->frame_num_offset < 0) {
      h->frame_num_offset += 256;
    }
    if (h->frame_num_offset == 0 || h->frame_num_offset >= h->prev_frame_num_offset) {
      av_log(h->s.avctx, AV_LOG_ERROR, "error in B-frame picture id\n");
      return -1;
    }
  } else {
    h->prev_frame_num = h->frame_num;
    h->frame_num = h->slice_num;
    h->prev_frame_num_offset = (h->frame_num - h->prev_frame_num);

    if (h->prev_frame_num_offset < 0) {
      h->prev_frame_num_offset += 256;
    }
  }

  for(m=0; m<2; m++){
    int i;
    for(i=0; i<4; i++){
      int j;
      for(j=-1; j<4; j++)
	h->ref_cache[m][scan8[0] + 8*i + j]= 1;
      h->ref_cache[m][scan8[0] + 8*i + j]= PART_NOT_AVAILABLE;
    }
  }
  
  for (s->mb_y=0; s->mb_y < s->mb_height; s->mb_y++) {
    for (s->mb_x=0; s->mb_x < s->mb_width; s->mb_x++) {

      if ( (s->gb.index + 7) >= s->gb.size_in_bits &&
	  ((s->gb.index & 7) == 0 || show_bits (&s->gb, (-s->gb.index & 7)) == 0)) {

	s->gb.index = h->next_slice_index;
	s->gb.size_in_bits = 8*buf_size;

	if (svq3_decode_slice_header (h))
	  return -1;

	/* TODO: support s->mb_skip_run */
      }

      mb_type = svq3_get_ue_golomb (&s->gb);

      if (s->pict_type == I_TYPE) {
	mb_type += 8;
      } else if (s->pict_type == B_TYPE && mb_type >= 4) {
	mb_type += 4;
      }
      if (mb_type > 33 || svq3_decode_mb (h, mb_type)) {
	av_log(h->s.avctx, AV_LOG_ERROR, "error while decoding MB %d %d\n", s->mb_x, s->mb_y);
	return -1;
      }

      if (mb_type != 0) {
	hl_decode_mb (h);
      }

      if (s->pict_type != B_TYPE && !s->low_delay) {
	s->current_picture.mb_type[s->mb_x + s->mb_y*s->mb_stride] =
			(s->pict_type == P_TYPE && mb_type < 8) ? (mb_type - 1) : -1;
      }
    }

    ff_draw_horiz_band(s, 16*s->mb_y, 16);
  }

  MPV_frame_end(s);

  if (s->pict_type == B_TYPE || s->low_delay) {
    *(AVFrame *) data = *(AVFrame *) &s->current_picture;
  } else {
    *(AVFrame *) data = *(AVFrame *) &s->last_picture;
  }

  avctx->frame_number = s->picture_number - 1;

  /* dont output the last pic after seeking */
  if (s->last_picture_ptr || s->low_delay) {
    *data_size = sizeof(AVFrame);
  }

  return buf_size;
}


AVCodec svq3_decoder = {
    "svq3",
    CODEC_TYPE_VIDEO,
    CODEC_ID_SVQ3,
    sizeof(H264Context),
    decode_init,
    NULL,
    decode_end,
    svq3_decode_frame,
    CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1,
};