StreamInfo::FrameType ParserMpeg2Video::parsePicture(unsigned char* data, int length) {
int frametype = GetFrameType(data, length);
// get I,P frames distance
if(frametype < 3 && m_curDts != DVD_NOPTS_VALUE && m_curPts != DVD_NOPTS_VALUE) {
m_frameDifference = m_curPts - m_curDts;
m_lastDts = m_curDts;
return ConvertFrameType(frametype);
}
// extrapolate DTS
if(m_curDts == DVD_NOPTS_VALUE && m_duration != 0) {
m_curDts = PtsAdd(m_lastDts, m_duration);
m_lastDts = m_curDts;
}
// B frames have DTS = PTS
if(frametype == 3 && m_curPts == DVD_NOPTS_VALUE) {
m_curPts = m_curDts;
}
// extrapolate PTS of I/P frame
if(frametype < 3 && m_curPts == DVD_NOPTS_VALUE) {
m_curPts = PtsAdd(m_curDts, m_frameDifference);
}
return ConvertFrameType(frametype);
}
void cParser::Parse(unsigned char *data, int datasize, bool pusi)
{
// get available data
int length = 0;
uint8_t* buffer = Get(length);
// do we have a sync ?
int framesize = 0;
if(length > m_headersize && buffer != NULL && CheckAlignmentHeader(buffer, framesize))
{
if(framesize > 0 && length >= framesize)
{
ParsePayload(buffer, framesize);
SendPayload(buffer, framesize);
m_curPTS = PtsAdd(m_curPTS, m_duration);
m_curDTS = PtsAdd(m_curDTS, m_duration);
Del(framesize);
}
PutData(data, datasize, pusi);
return;
}
// try to find sync
int offset = FindAlignmentOffset(buffer, length, 0, framesize);
if(offset != -1)
{
INFOLOG("sync found at offset %i (streamtype: %s / %i bytes in buffer / framesize: %i bytes)", offset, m_demuxer->TypeName(), Available(), framesize);
Del(offset);
}
PutData(data, datasize, pusi);
}
int ParserMpeg2Video::parsePayload(unsigned char* data, int length) {
// lookup sequence start code
int o = findStartCode(data, length, 0, MPEG2_SEQUENCE_START);
if(o >= 0) {
// skip sequence start code
o += 4;
// parse picture sequence (width, height, aspect, duration)
parseSequenceStart(data + o, length - 4);
}
// just to be sure, exit if there's isn't any duration
if(m_duration == 0) {
return length;
}
// check for picture start codes
int s = findStartCode(data, length, 0, MPEG2_PICTURE_START);
// abort if there isn't any picture information
if(s == -1) {
return length;
}
int e = findStartCode(data, length, s + 4, MPEG2_PICTURE_START);
o = s;
s = 0;
// divide this packet into frames
while(e != -1) {
// parse and send payload data
m_frameType = parsePicture(data + o, e - o);
Parser::sendPayload(data + s, e - s);
// get next picture offsets
s = e;
o = s;
e = findStartCode(data, length, s + 4, MPEG2_PICTURE_START);
// increment timestamps
m_curPts = DVD_NOPTS_VALUE;
m_curDts = PtsAdd(m_curDts, m_duration);
}
// append last part
m_frameType = parsePicture(data + o, length - o);
Parser::sendPayload(data + s, length - s);
return length;
}
