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Added more H264 SPS decoding

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This commit is contained in:
Thulinma 2016-09-02 14:43:33 +02:00
parent e8e97adb49
commit eb5cdb32b1
2 changed files with 49 additions and 19 deletions
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61
lib/h264.cpp
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@ -88,15 +88,27 @@ namespace h264 {
dataLen = Bit::btohs(dtscInit.data() + 6);
}
void skipScalingList(Utils::bitstream & bs, size_t listSize){
size_t lastScale = 8;
size_t nextScale = 8;
for (size_t i = 0; i < listSize; i++){
if (nextScale){
uint64_t deltaScale = bs.getExpGolomb();
nextScale = (lastScale + deltaScale + 256) % 256;
}
lastScale = (nextScale ? nextScale : lastScale);
}
}
SPSMeta sequenceParameterSet::getCharacteristics() const {
SPSMeta result;
result.sep_col_plane = false;
//For calculating width
unsigned int widthInMbs = 0;
unsigned int cropHorizontal = 0;
//For calculating height
bool mbsOnlyFlag = 0;
unsigned int heightInMapUnits = 0;
unsigned int cropVertical = 0;
@ -121,33 +133,44 @@ namespace h264 {
bs.getUExpGolomb();
if (profileIdc == 100 || profileIdc == 110 || profileIdc == 122 || profileIdc == 244 || profileIdc == 44 || profileIdc == 83 || profileIdc == 86 || profileIdc == 118 || profileIdc == 128) {
//chroma format idc
if (bs.getUExpGolomb() == 3) {
bs.skip(1);
char chromaFormatIdc = bs.getUExpGolomb();
if (chromaFormatIdc == 3) {
result.sep_col_plane = (bs.get(1) == 1);
}
bs.getUExpGolomb();
bs.getUExpGolomb();
bs.skip(1);
if (bs.get(1)) {
DEBUG_MSG(DLVL_DEVEL, "Scaling matrix not implemented yet");
bs.getUExpGolomb();//luma
bs.getUExpGolomb();//chroma
bs.skip(1);//transform bypass
if (bs.get(1)) {//Scaling matrix is present
char listSize = (chromaFormatIdc == 3 ? 12 : 8);
for (size_t i = 0; i < listSize; i++){
bool thisListPresent = bs.get(1);
if (thisListPresent){
if (i < 6){
skipScalingList(bs, 16);
}else{
skipScalingList(bs, 64);
}
}
bs.getUExpGolomb();
unsigned int pic_order_cnt_type = bs.getUExpGolomb();
if (!pic_order_cnt_type) {
bs.getUExpGolomb();
} else if (pic_order_cnt_type == 1) {
}
}
}
result.log2_max_frame_num = bs.getUExpGolomb() + 4;
result.cnt_type = bs.getUExpGolomb();
if (!result.cnt_type) {
result.log2_max_order_cnt = bs.getUExpGolomb() + 4;
} else if (result.cnt_type == 1) {
DEBUG_MSG(DLVL_DEVEL, "This part of the implementation is incomplete(2), to be continued. If this message is shown, contact developers immediately.");
}
bs.getUExpGolomb();
bs.skip(1);
//Stop skipping data and start doing usefull stuff
result.max_ref_frames = bs.getUExpGolomb();//max_num_ref_frames
result.gaps = (bs.get(1) == 1);//gaps in frame num allowed
//Stop skipping data and start doing useful stuff
widthInMbs = bs.getUExpGolomb() + 1;
heightInMapUnits = bs.getUExpGolomb() + 1;
mbsOnlyFlag = bs.get(1);//Gets used in height calculation
if (!mbsOnlyFlag) {
result.mbs_only = (bs.get(1) == 1);//Gets used in height calculation
if (!result.mbs_only) {
bs.skip(1);
}
bs.skip(1);
@ -191,7 +214,7 @@ namespace h264 {
}
result.width = (widthInMbs * 16) - (cropHorizontal * 2);
result.height = ((mbsOnlyFlag ? 1 : 2) * heightInMapUnits * 16) - (cropVertical * 2);
result.height = ((result.mbs_only ? 1 : 2) * heightInMapUnits * 16) - (cropVertical * 2);
return result;
}

7
lib/h264.h
View file

@ -14,6 +14,13 @@ namespace h264 {
double fps;
uint8_t profile;
uint8_t level;
bool sep_col_plane;
uint8_t cnt_type;
bool gaps;///< Gaps in frame num allowed flag
bool mbs_only;///<MBS only flag
uint16_t log2_max_frame_num;
uint16_t log2_max_order_cnt;
uint16_t max_ref_frames;///<Maximum number of reference frames
};
///Class for analyzing generic nal units