svq3.c

tcpmp播放器的flv插件

      const int b_xy = (4*s->mb_x+(j>>2)) + (4*s->mb_y+(i>>2))*h->b_stride;
      int dxy;
      x = 16*s->mb_x + j;
      y = 16*s->mb_y + i;
      k = ((j>>2)&1) + ((i>>1)&2) + ((j>>1)&4) + (i&8);

      if (mode != PREDICT_MODE) {
	pred_motion (h, k, (part_width >> 2), dir, 1, &mx, &my);
      } else {
	mx = s->next_picture.motion_val[0][b_xy][0]<<1;
	my = s->next_picture.motion_val[0][b_xy][1]<<1;

	if (dir == 0) {
	  mx = ((mx * h->frame_num_offset) / h->prev_frame_num_offset + 1)>>1;
	  my = ((my * h->frame_num_offset) / h->prev_frame_num_offset + 1)>>1;
	} else {
	  mx = ((mx * (h->frame_num_offset - h->prev_frame_num_offset)) / h->prev_frame_num_offset + 1)>>1;
	  my = ((my * (h->frame_num_offset - h->prev_frame_num_offset)) / h->prev_frame_num_offset + 1)>>1;
	}
      }

      /* clip motion vector prediction to frame border */
      mx = clip (mx, extra_width - 6*x, h_edge_pos - 6*x);
      my = clip (my, extra_width - 6*y, v_edge_pos - 6*y);

      /* get (optional) motion vector differential */
      if (mode == PREDICT_MODE) {
	dx = dy = 0;
      } else {
	dy = svq3_get_se_golomb (&s->gb);
	dx = svq3_get_se_golomb (&s->gb);

	if (dx == INVALID_VLC || dy == INVALID_VLC) {
          av_log(h->s.avctx, AV_LOG_ERROR, "invalid MV vlc\n");
	  return -1;
	}
      }

      /* compute motion vector */
      if (mode == THIRDPEL_MODE) {
	int fx, fy;
	mx = ((mx + 1)>>1) + dx;
	my = ((my + 1)>>1) + dy;
	fx= ((unsigned)(mx + 0x3000))/3 - 0x1000;
	fy= ((unsigned)(my + 0x3000))/3 - 0x1000;
	dxy= (mx - 3*fx) + 4*(my - 3*fy);

	svq3_mc_dir_part (s, x, y, part_width, part_height, fx, fy, dxy, 1, dir, avg);
	mx += mx;
	my += my;
      } else if (mode == HALFPEL_MODE || mode == PREDICT_MODE) {
	mx = ((unsigned)(mx + 1 + 0x3000))/3 + dx - 0x1000;
	my = ((unsigned)(my + 1 + 0x3000))/3 + dy - 0x1000;
	dxy= (mx&1) + 2*(my&1);

	svq3_mc_dir_part (s, x, y, part_width, part_height, mx>>1, my>>1, dxy, 0, dir, avg);
	mx *= 3;
	my *= 3;
      } else {
	mx = ((unsigned)(mx + 3 + 0x6000))/6 + dx - 0x1000;
	my = ((unsigned)(my + 3 + 0x6000))/6 + dy - 0x1000;

	svq3_mc_dir_part (s, x, y, part_width, part_height, mx, my, 0, 0, dir, avg);
	mx *= 6;
	my *= 6;
      }

      /* update mv_cache */
      if (mode != PREDICT_MODE) {
	int32_t mv = pack16to32(mx,my);

	if (part_height == 8 && i < 8) {
	  *(int32_t *) h->mv_cache[dir][scan8[k] + 1*8] = mv;

	  if (part_width == 8 && j < 8) {
	    *(int32_t *) h->mv_cache[dir][scan8[k] + 1 + 1*8] = mv;
	  }
	}
	if (part_width == 8 && j < 8) {
	  *(int32_t *) h->mv_cache[dir][scan8[k] + 1] = mv;
	}
	if (part_width == 4 || part_height == 4) {
	  *(int32_t *) h->mv_cache[dir][scan8[k]] = mv;
	}
      }

      /* write back motion vectors */
      fill_rectangle(s->current_picture.motion_val[dir][b_xy], part_width>>2, part_height>>2, h->b_stride, pack16to32(mx,my), 4);
    }
  }

  return 0;
}

static int svq3_decode_mb (H264Context *h, unsigned int mb_type) {
  int i, j, k, m, dir, mode;
  int cbp = 0;
  uint32_t vlc;
  int8_t *top, *left;
  MpegEncContext *const s = (MpegEncContext *) h;
  const int mb_xy = s->mb_x + s->mb_y*s->mb_stride;
  const int b_xy = 4*s->mb_x + 4*s->mb_y*h->b_stride;

  h->top_samples_available	= (s->mb_y == 0) ? 0x33FF : 0xFFFF;
  h->left_samples_available	= (s->mb_x == 0) ? 0x5F5F : 0xFFFF;
  h->topright_samples_available	= 0xFFFF;

  if (mb_type == 0) {		/* SKIP */
    if (s->pict_type == P_TYPE || s->next_picture.mb_type[mb_xy] == -1) {
      svq3_mc_dir_part (s, 16*s->mb_x, 16*s->mb_y, 16, 16, 0, 0, 0, 0, 0, 0);

      if (s->pict_type == B_TYPE) {
	svq3_mc_dir_part (s, 16*s->mb_x, 16*s->mb_y, 16, 16, 0, 0, 0, 0, 1, 1);
      }

      mb_type = MB_TYPE_SKIP;
    } else {
      mb_type= FFMIN(s->next_picture.mb_type[mb_xy], 6);
      if(svq3_mc_dir (h, mb_type, PREDICT_MODE, 0, 0) < 0)
        return -1;
      if(svq3_mc_dir (h, mb_type, PREDICT_MODE, 1, 1) < 0)
        return -1;

      mb_type = MB_TYPE_16x16;
    }
  } else if (mb_type < 8) {	/* INTER */
    if (h->thirdpel_flag && h->halfpel_flag == !get_bits (&s->gb, 1)) {
      mode = THIRDPEL_MODE;
    } else if (h->halfpel_flag && h->thirdpel_flag == !get_bits (&s->gb, 1)) {
      mode = HALFPEL_MODE;
    } else {
      mode = FULLPEL_MODE;
    }

    /* fill caches */
    /* note ref_cache should contain here:
        ????????
        ???11111
        N??11111
        N??11111
        N??11111
        N
    */
    
    for (m=0; m < 2; m++) {
      if (s->mb_x > 0 && h->intra4x4_pred_mode[mb_xy - 1][0] != -1) {
	for (i=0; i < 4; i++) {
	  *(uint32_t *) h->mv_cache[m][scan8[0] - 1 + i*8] = *(uint32_t *) s->current_picture.motion_val[m][b_xy - 1 + i*h->b_stride];
	}
      } else {
	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) {
      if(svq3_mc_dir (h, (mb_type - 1), mode, 0, 0) < 0)
        return -1;
    } else {	/* B_TYPE */
      if (mb_type != 2) {
	if(svq3_mc_dir (h, 0, mode, 0, 0) < 0)
          return -1;
      } 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) {
	if(svq3_mc_dir (h, 0, mode, 1, (mb_type == 3)) < 0)
          return -1;
      } 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){
          av_log(h->s.avctx, AV_LOG_ERROR, "luma prediction:%d\n", vlc);
	  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){
          av_log(h->s.avctx, AV_LOG_ERROR, "weird prediction\n");
	  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){
      av_log(h->s.avctx, AV_LOG_ERROR, "check_intra_pred_mode = -1\n");
      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){
      av_log(h->s.avctx, AV_LOG_ERROR, "cbp_vlc=%d\n", vlc);
      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){
      av_log(h->s.avctx, AV_LOG_ERROR, "qscale:%d\n", s->qscale);
      return -1;
    }
  }
  if (IS_INTRA16x16(mb_type)) {
    if (svq3_decode_block (&s->gb, h->mb, 0, 0)){
      av_log(h->s.avctx, AV_LOG_ERROR, "error while decoding intra luma dc\n");
      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)){
            av_log(h->s.avctx, AV_LOG_ERROR, "error while decoding block\n");
	    return -1;
          }
	}
      }
    }