void RCInitChromaQP(AVCEncObject *encvid)
{
AVCCommonObj *video = encvid->common;
AVCMacroblock *currMB = video->currMB;
int q_bits;
/* we have to do the same thing for AVC_CLIP3(0,51,video->QSy) */
video->QPy_div_6 = (currMB->QPy * 43) >> 8;
video->QPy_mod_6 = currMB->QPy - 6 * video->QPy_div_6;
currMB->QPc = video->QPc = mapQPi2QPc[AVC_CLIP3(0, 51, currMB->QPy + video->currPicParams->chroma_qp_index_offset)];
video->QPc_div_6 = (video->QPc * 43) >> 8;
video->QPc_mod_6 = video->QPc - 6 * video->QPc_div_6;
/* pre-calculate this to save computation */
q_bits = 4 + video->QPy_div_6;
if (video->slice_type == AVC_I_SLICE)
{
encvid->qp_const = 682 << q_bits; // intra
}
else
{
encvid->qp_const = 342 << q_bits; // inter
}
q_bits = 4 + video->QPc_div_6;
if (video->slice_type == AVC_I_SLICE)
{
encvid->qp_const_c = 682 << q_bits; // intra
}
else
{
encvid->qp_const_c = 342 << q_bits; // inter
}
encvid->lambda_mode = QP2QUANT[AVC_MAX(0, currMB->QPy-SHIFT_QP)];
encvid->lambda_motion = LAMBDA_FACTOR(encvid->lambda_mode);
return ;
}
/* update video->mb_skip_run */
AVCDec_Status DecodeMB(AVCDecObject *decvid)
{
AVCDec_Status status;
AVCCommonObj *video = decvid->common;
AVCDecBitstream *stream = decvid->bitstream;
AVCMacroblock *currMB = video->currMB;
uint mb_type;
int slice_type = video->slice_type;
int temp;
currMB->QPy = video->QPy;
currMB->QPc = video->QPc;
if (slice_type == AVC_P_SLICE)
{
if (video->mb_skip_run < 0)
{
ue_v(stream, (uint *)&(video->mb_skip_run));
}
if (video->mb_skip_run == 0)
{
/* this will not handle the case where the slice ends with a mb_skip_run == 0 and no following MB data */
ue_v(stream, &mb_type);
if (mb_type > 30)
{
return AVCDEC_FAIL;
}
InterpretMBModeP(currMB, mb_type);
video->mb_skip_run = -1;
}
else
{
/* see subclause 7.4.4 for more details on how
mb_field_decoding_flag is derived in case of skipped MB */
currMB->mb_intra = FALSE;
currMB->mbMode = AVC_SKIP;
currMB->MbPartWidth = currMB->MbPartHeight = 16;
currMB->NumMbPart = 1;
currMB->NumSubMbPart[0] = currMB->NumSubMbPart[1] =
currMB->NumSubMbPart[2] = currMB->NumSubMbPart[3] = 1; //
currMB->SubMbPartWidth[0] = currMB->SubMbPartWidth[1] =
currMB->SubMbPartWidth[2] = currMB->SubMbPartWidth[3] = currMB->MbPartWidth;
currMB->SubMbPartHeight[0] = currMB->SubMbPartHeight[1] =
currMB->SubMbPartHeight[2] = currMB->SubMbPartHeight[3] = currMB->MbPartHeight;
oscl_memset(currMB->nz_coeff, 0, sizeof(uint8)*NUM_BLKS_IN_MB);
currMB->CBP = 0;
video->cbp4x4 = 0;
/* for skipped MB, always look at the first entry in RefPicList */
currMB->RefIdx[0] = currMB->RefIdx[1] =
currMB->RefIdx[2] = currMB->RefIdx[3] = video->RefPicList0[0]->RefIdx;
InterMBPrediction(video);
video->mb_skip_run--;
return AVCDEC_SUCCESS;
}
}
else
{
/* Then decode mode and MV */
ue_v(stream, &mb_type);
if (mb_type > 25)
{
return AVCDEC_FAIL;
}
InterpretMBModeI(currMB, mb_type);
}
if (currMB->mbMode != AVC_I_PCM)
{
if (currMB->mbMode == AVC_P8 || currMB->mbMode == AVC_P8ref0)
{
status = sub_mb_pred(video, currMB, stream);
}
else
{
status = mb_pred(video, currMB, stream) ;
}
if (status != AVCDEC_SUCCESS)
{
return status;
}
if (currMB->mbMode != AVC_I16)
{
/* decode coded_block_pattern */
status = DecodeCBP(currMB, stream);
if (status != AVCDEC_SUCCESS)
{
return status;
}
}
if (currMB->CBP > 0 || currMB->mbMode == AVC_I16)
{
se_v(stream, &temp);
if (temp)
{
temp += (video->QPy + 52);
currMB->QPy = video->QPy = temp - 52 * (temp * 79 >> 12);
if (currMB->QPy > 51 || currMB->QPy < 0)
{
video->QPy = AVC_CLIP3(0, 51, video->QPy);
// return AVCDEC_FAIL;
}
video->QPy_div_6 = (video->QPy * 43) >> 8;
video->QPy_mod_6 = video->QPy - 6 * video->QPy_div_6;
currMB->QPc = video->QPc = mapQPi2QPc[AVC_CLIP3(0, 51, video->QPy + video->currPicParams->chroma_qp_index_offset)];
video->QPc_div_6 = (video->QPc * 43) >> 8;
video->QPc_mod_6 = video->QPc - 6 * video->QPc_div_6;
}
}
/* decode residue and inverse transform */
status = residual(decvid, currMB);
if (status != AVCDEC_SUCCESS)
{
return status;
}
}