unsigned H264or5VideoStreamParser::parse() {
static int aaaa = 0 ;
aaaa++;
qDebug()<<"H264or5VideoStreamParser::parse() { 868 aaaa" <<aaaa;
try {
// The stream must start with a 0x00000001:
if (!fHaveSeenFirstStartCode) {
// Skip over any input bytes that precede the first 0x00000001:
u_int32_t first4Bytes;
while ((first4Bytes = test4Bytes()) != 0x00000001) {
get1Byte(); setParseState(); // ensures that we progress over bad data
}
skipBytes(4); // skip this initial code
setParseState();
fHaveSeenFirstStartCode = True; // from now on
}
if (fOutputStartCodeSize > 0 && curFrameSize() == 0 && !haveSeenEOF()) {
// Include a start code in the output:
save4Bytes(0x00000001);
}
// Then save everything up until the next 0x00000001 (4 bytes) or 0x000001 (3 bytes), or we hit EOF.
// Also make note of the first byte, because it contains the "nal_unit_type":
if (haveSeenEOF()) {
// We hit EOF the last time that we tried to parse this data, so we know that any remaining unparsed data
// forms a complete NAL unit, and that there's no 'start code' at the end:
unsigned remainingDataSize = totNumValidBytes() - curOffset();
#ifdef DEBUG
unsigned const trailingNALUnitSize = remainingDataSize;
#endif
while (remainingDataSize > 0) {
u_int8_t nextByte = get1Byte();
if (!fHaveSeenFirstByteOfNALUnit) {
fFirstByteOfNALUnit = nextByte;
fHaveSeenFirstByteOfNALUnit = True;
}
saveByte(nextByte);
--remainingDataSize;
}
#ifdef DEBUG
if (fHNumber == 264) {
u_int8_t nal_ref_idc = (fFirstByteOfNALUnit&0x60)>>5;
u_int8_t nal_unit_type = fFirstByteOfNALUnit&0x1F;
fprintf(stderr, "Parsed trailing %d-byte NAL-unit (nal_ref_idc: %d, nal_unit_type: %d (\"%s\"))\n",
trailingNALUnitSize, nal_ref_idc, nal_unit_type, nal_unit_type_description_h264[nal_unit_type]);
} else { // 265
u_int8_t nal_unit_type = (fFirstByteOfNALUnit&0x7E)>>1;
fprintf(stderr, "Parsed trailing %d-byte NAL-unit (nal_unit_type: %d (\"%s\"))\n",
trailingNALUnitSize, nal_unit_type, nal_unit_type_description_h265[nal_unit_type]);
}
#endif
(void)get1Byte(); // forces another read, which will cause EOF to get handled for real this time
return 0;
} else {
Boolean MatroskaFileParser::parseEBMLNumber(EBMLNumber& num) {
unsigned i;
u_int8_t bitmask = 0x80;
for (i = 0; i < EBML_NUMBER_MAX_LEN; ++i) {
while (1) {
if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) return False; // We've hit our pre-set limit
num.data[i] = get1Byte();
++fCurOffsetInFile;
// If we're looking for an id, skip any leading bytes that don't contain a '1' in the first 4 bits:
if (i == 0/*we're a leading byte*/ && !num.stripLeading1/*we're looking for an id*/ && (num.data[i]&0xF0) == 0) {
setParseState(); // ensures that we make forward progress if the parsing gets interrupted
continue;
}
break;
}
if ((num.data[0]&bitmask) != 0) {
// num[i] is the last byte of the id
if (num.stripLeading1) num.data[0] &=~ bitmask;
break;
}
bitmask >>= 1;
}
if (i == EBML_NUMBER_MAX_LEN) return False;
num.len = i+1;
return True;
}
unsigned MPEG4VideoStreamParser
::parseVisualObjectSequence(Boolean haveSeenStartCode) {
#ifdef DEBUG
fprintf(stderr, "parsing VisualObjectSequence\n");
#endif
usingSource()->startNewConfig();
u_int32_t first4Bytes;
if (!haveSeenStartCode) {
while ((first4Bytes = test4Bytes()) != VISUAL_OBJECT_SEQUENCE_START_CODE) {
#ifdef DEBUG
fprintf(stderr, "ignoring non VS header: 0x%08x\n", first4Bytes);
#endif
get1Byte(); setParseState(PARSING_VISUAL_OBJECT_SEQUENCE);
// ensures we progress over bad data
}
first4Bytes = get4Bytes();
} else {
// We've already seen the start code
first4Bytes = VISUAL_OBJECT_SEQUENCE_START_CODE;
}
save4Bytes(first4Bytes);
// The next byte is the "profile_and_level_indication":
u_int8_t pali = get1Byte();
#ifdef DEBUG
fprintf(stderr, "profile_and_level_indication: %02x\n", pali);
#endif
saveByte(pali);
usingSource()->fProfileAndLevelIndication = pali;
// Now, copy all bytes that we see, up until we reach
// a VISUAL_OBJECT_START_CODE:
u_int32_t next4Bytes = get4Bytes();
while (next4Bytes != VISUAL_OBJECT_START_CODE) {
saveToNextCode(next4Bytes);
}
setParseState(PARSING_VISUAL_OBJECT);
// Compute this frame's presentation time:
usingSource()->computePresentationTime(fTotalTicksSinceLastTimeCode);
// This header forms part of the 'configuration' information:
usingSource()->appendToNewConfig(fStartOfFrame, curFrameSize());
return curFrameSize();
}
unsigned MPEG4VideoStreamParser::parseVisualObject() {
#ifdef DEBUG
fprintf(stderr, "parsing VisualObject\n");
#endif
// Note that we've already read the VISUAL_OBJECT_START_CODE
save4Bytes(VISUAL_OBJECT_START_CODE);
// Next, extract the "visual_object_type" from the next 1 or 2 bytes:
u_int8_t nextByte = get1Byte(); saveByte(nextByte);
Boolean is_visual_object_identifier = (nextByte&0x80) != 0;
u_int8_t visual_object_type;
if (is_visual_object_identifier) {
#ifdef DEBUG
fprintf(stderr, "visual_object_verid: 0x%x; visual_object_priority: 0x%x\n", (nextByte&0x78)>>3, (nextByte&0x07));
#endif
nextByte = get1Byte(); saveByte(nextByte);
visual_object_type = (nextByte&0xF0)>>4;
} else {
unsigned MPEG1or2VideoStreamParser
::parseVideoSequenceHeader(Boolean haveSeenStartCode) {
#ifdef DEBUG
fprintf(stderr, "parsing video sequence header\n");
#endif
unsigned first4Bytes;
if (!haveSeenStartCode) {
while ((first4Bytes = test4Bytes()) != VIDEO_SEQUENCE_HEADER_START_CODE) {
#ifdef DEBUG
fprintf(stderr, "ignoring non video sequence header: 0x%08x\n", first4Bytes);
#endif
get1Byte(); setParseState(PARSING_VIDEO_SEQUENCE_HEADER);
// ensures we progress over bad data
}
first4Bytes = get4Bytes();
} else {
// We've already seen the start code
first4Bytes = VIDEO_SEQUENCE_HEADER_START_CODE;
}
save4Bytes(first4Bytes);
// Next, extract the size and rate parameters from the next 8 bytes
unsigned paramWord1 = get4Bytes();
save4Bytes(paramWord1);
unsigned next4Bytes = get4Bytes();
#ifdef DEBUG
unsigned short horizontal_size_value = (paramWord1&0xFFF00000)>>(32-12);
unsigned short vertical_size_value = (paramWord1&0x000FFF00)>>8;
unsigned char aspect_ratio_information = (paramWord1&0x000000F0)>>4;
#endif
unsigned char frame_rate_code = (paramWord1&0x0000000F);
usingSource()->fFrameRate = frameRateFromCode[frame_rate_code];
#ifdef DEBUG
unsigned bit_rate_value = (next4Bytes&0xFFFFC000)>>(32-18);
unsigned vbv_buffer_size_value = (next4Bytes&0x00001FF8)>>3;
fprintf(stderr, "horizontal_size_value: %d, vertical_size_value: %d, aspect_ratio_information: %d, frame_rate_code: %d (=>%f fps), bit_rate_value: %d (=>%d bps), vbv_buffer_size_value: %d\n", horizontal_size_value, vertical_size_value, aspect_ratio_information, frame_rate_code, usingSource()->fFrameRate, bit_rate_value, bit_rate_value*400, vbv_buffer_size_value);
#endif
// Now, copy all bytes that we see, up until we reach a GROUP_START_CODE
// or a PICTURE_START_CODE:
do {
saveToNextCode(next4Bytes);
} while (next4Bytes != GROUP_START_CODE && next4Bytes != PICTURE_START_CODE);
setParseState((next4Bytes == GROUP_START_CODE)
? PARSING_GOP_HEADER_SEEN_CODE : PARSING_PICTURE_HEADER);
// Compute this frame's timestamp by noting how many pictures we've seen
// since the last GOP header:
usingSource()->computePresentationTime(fPicturesSinceLastGOP);
// Save this video_sequence_header, in case we need to insert a copy
// into the stream later:
saveCurrentVSH();
return curFrameSize();
}
void MPEGProgramStreamParser::parsePackHeader() {
#ifdef DEBUG
fprintf(stderr, "parsing pack header\n"); fflush(stderr);
#endif
unsigned first4Bytes;
while (1) {
first4Bytes = test4Bytes();
// We're supposed to have a pack header here, but check also for
// a system header or a PES packet, just in case:
if (first4Bytes == PACK_START_CODE) {
skipBytes(4);
break;
} else if (first4Bytes == SYSTEM_HEADER_START_CODE) {
#ifdef DEBUG
fprintf(stderr, "found system header instead of pack header\n");
#endif
setParseState(PARSING_SYSTEM_HEADER);
return;
} else if (isPacketStartCode(first4Bytes)) {
#ifdef DEBUG
fprintf(stderr, "found packet start code 0x%02x instead of pack header\n", first4Bytes);
#endif
setParseState(PARSING_PES_PACKET);
return;
}
setParseState(PARSING_PACK_HEADER); // ensures we progress over bad data
if ((first4Bytes&0xFF) > 1) { // a system code definitely doesn't start here
skipBytes(4);
} else {
skipBytes(1);
}
}
// The size of the pack header differs depending on whether it's
// MPEG-1 or MPEG-2. The next byte tells us this:
unsigned char nextByte = get1Byte();
MPEG1or2Demux::SCR& scr = fUsingSource->fLastSeenSCR; // alias
if ((nextByte&0xF0) == 0x20) { // MPEG-1
fUsingSource->fMPEGversion = 1;
scr.highBit = (nextByte&0x08)>>3;
scr.remainingBits = (nextByte&0x06)<<29;
unsigned next4Bytes = get4Bytes();
scr.remainingBits |= (next4Bytes&0xFFFE0000)>>2;
scr.remainingBits |= (next4Bytes&0x0000FFFE)>>1;
scr.extension = 0;
scr.isValid = True;
skipBits(24);
#if defined(DEBUG_TIMESTAMPS) || defined(DEBUG_SCR_TIMESTAMPS)
fprintf(stderr, "pack hdr system_clock_reference_base: 0x%x",
scr.highBit);
fprintf(stderr, "%08x\n", scr.remainingBits);
#endif
} else if ((nextByte&0xC0) == 0x40) { // MPEG-2
Boolean MatroskaFileParser::parseEBMLVal_unsigned64(EBMLDataSize& size, u_int64_t& result) {
u_int64_t sv = size.val();
if (sv > 8) return False; // size too large
result = 0; // initially
for (unsigned i = (unsigned)sv; i > 0; --i) {
if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) return False; // We've hit our pre-set limit
u_int8_t c = get1Byte();
++fCurOffsetInFile;
result = result*256 + c;
}
return True;
}
unsigned H264VideoStreamParser::parseNALUnit()
{
u_int32_t test = test4Bytes();
int numBytes = 0;
while (test != 0x00000001)
{
saveByte(get1Byte());
numBytes++;
test = test4Bytes();
}
//skipBytes(8);
return curFrameSize();
}
Boolean MatroskaFileParser::parseEBMLVal_binary(EBMLDataSize& size, u_int8_t*& result) {
unsigned resultLength = (unsigned)size.val();
result = new u_int8_t[resultLength];
if (result == NULL) return False;
u_int8_t* p = result;
unsigned i;
for (i = 0; i < resultLength; ++i) {
if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) break; // We've hit our pre-set limit
u_int8_t c = get1Byte();
++fCurOffsetInFile;
*p++ = c;
}
if (i < resultLength) { // an error occurred
delete[] result;
result = NULL;
return False;
}
return True;
}
Boolean MatroskaFileParser::parseEBMLVal_string(EBMLDataSize& size, char*& result) {
unsigned resultLength = (unsigned)size.val();
result = new char[resultLength + 1]; // allow for the trailing '\0'
if (result == NULL) return False;
char* p = result;
unsigned i;
for (i = 0; i < resultLength; ++i) {
if (fLimitOffsetInFile > 0 && fCurOffsetInFile > fLimitOffsetInFile) break; // We've hit our pre-set limit
u_int8_t c = get1Byte();
++fCurOffsetInFile;
*p++ = c;
}
if (i < resultLength) { // an error occurred
delete[] result;
result = NULL;
return False;
}
*p = '\0';
return True;
}
unsigned H264VideoStreamParser::parse() {
try {
// The stream must start with a 0x00000001:
if (!fHaveSeenFirstStartCode) {
// Skip over any input bytes that precede the first 0x00000001:
u_int32_t first4Bytes;
while ((first4Bytes = test4Bytes()) != 0x00000001) {
get1Byte(); setParseState(); // ensures that we progress over bad data
}
skipBytes(4); // skip this initial code
setParseState();
fHaveSeenFirstStartCode = True; // from now on
}
if (fOutputStartCodeSize > 0 && curFrameSize() == 0 && !haveSeenEOF()) {
// Include a start code in the output:
save4Bytes(0x00000001);
}
// Then save everything up until the next 0x00000001 (4 bytes) or 0x000001 (3 bytes), or we hit EOF.
// Also make note of the first byte, because it contains the "nal_unit_type":
if (haveSeenEOF()) {
// We hit EOF the last time that we tried to parse this data, so we know that any remaining unparsed data
// forms a complete NAL unit, and that there's no 'start code' at the end:
unsigned remainingDataSize = totNumValidBytes() - curOffset();
#ifdef DEBUG
unsigned const trailingNALUnitSize = remainingDataSize;
#endif
while (remainingDataSize > 0) {
u_int8_t nextByte = get1Byte();
if (!fHaveSeenFirstByteOfNALUnit) {
fFirstByteOfNALUnit = nextByte;
fHaveSeenFirstByteOfNALUnit = True;
}
saveByte(nextByte);
--remainingDataSize;
}
#ifdef DEBUG
u_int8_t nal_ref_idc = (fFirstByteOfNALUnit&0x60)>>5;
u_int8_t nal_unit_type = fFirstByteOfNALUnit&0x1F;
fprintf(stderr, "Parsed trailing %d-byte NAL-unit (nal_ref_idc: %d, nal_unit_type: %d (\"%s\"))\n",
trailingNALUnitSize, nal_ref_idc, nal_unit_type, nal_unit_type_description[nal_unit_type]);
#endif
(void)get1Byte(); // forces another read, which will cause EOF to get handled for real this time
return 0;
} else {
u_int32_t next4Bytes = test4Bytes();
if (!fHaveSeenFirstByteOfNALUnit) {
fFirstByteOfNALUnit = next4Bytes>>24;
fHaveSeenFirstByteOfNALUnit = True;
}
while (next4Bytes != 0x00000001 && (next4Bytes&0xFFFFFF00) != 0x00000100) {
// We save at least some of "next4Bytes".
if ((unsigned)(next4Bytes&0xFF) > 1) {
// Common case: 0x00000001 or 0x000001 definitely doesn't begin anywhere in "next4Bytes", so we save all of it:
save4Bytes(next4Bytes);
skipBytes(4);
} else {
// Save the first byte, and continue testing the rest:
saveByte(next4Bytes>>24);
skipBytes(1);
}
setParseState(); // ensures forward progress
next4Bytes = test4Bytes();
}
// Assert: next4Bytes starts with 0x00000001 or 0x000001, and we've saved all previous bytes (forming a complete NAL unit).
// Skip over these remaining bytes, up until the start of the next NAL unit:
if (next4Bytes == 0x00000001) {
skipBytes(4);
} else {
skipBytes(3);
}
}
Boolean MatroskaFileParser::deliverFrameWithinBlock() {
#ifdef DEBUG
fprintf(stderr, "delivering frame within SimpleBlock or Block\n");
#endif
do {
MatroskaTrack* track = fOurFile.lookup(fBlockTrackNumber);
if (track == NULL) break; // shouldn't happen
MatroskaDemuxedTrack* demuxedTrack = fOurDemux->lookupDemuxedTrack(fBlockTrackNumber);
if (demuxedTrack == NULL) break; // shouldn't happen
if (!demuxedTrack->isCurrentlyAwaitingData()) {
// Someone has been reading this stream, but isn't right now.
// We can't deliver this frame until he asks for it, so punt for now.
// The next time he asks for a frame, he'll get it.
#ifdef DEBUG
fprintf(stderr, "\tdeferring delivery of frame #%d (%d bytes)", fNextFrameNumberToDeliver, fFrameSizesWithinBlock[fNextFrameNumberToDeliver]);
if (track->haveSubframes()) fprintf(stderr, "[offset %d]", fCurOffsetWithinFrame);
fprintf(stderr, "\n");
#endif
restoreSavedParserState(); // so we read from the beginning next time
return False;
}
unsigned frameSize = fFrameSizesWithinBlock[fNextFrameNumberToDeliver];
if (track->haveSubframes()) {
// The next "track->subframeSizeSize" bytes contain the length of a 'subframe':
if (fCurOffsetWithinFrame + track->subframeSizeSize > frameSize) break; // sanity check
unsigned subframeSize = 0;
for (unsigned i = 0; i < track->subframeSizeSize; ++i) {
u_int8_t c;
getCommonFrameBytes(track, &c, 1, 0);
if (fCurFrameNumBytesToGet > 0) { // it'll be 1
c = get1Byte();
++fCurOffsetWithinFrame;
}
subframeSize = subframeSize*256 + c;
}
if (subframeSize == 0 || fCurOffsetWithinFrame + subframeSize > frameSize) break; // sanity check
frameSize = subframeSize;
}
// Compute the presentation time of this frame (from the cluster timecode, the block timecode, and the default duration):
double pt = (fClusterTimecode+fBlockTimecode)*(fOurFile.fTimecodeScale/1000000000.0)
+ fNextFrameNumberToDeliver*(track->defaultDuration/1000000000.0);
if (fPresentationTimeOffset == 0.0) {
// This is the first time we've computed a presentation time. Compute an offset to make the presentation times aligned
// with 'wall clock' time:
struct timeval timeNow;
gettimeofday(&timeNow, NULL);
double ptNow = timeNow.tv_sec + timeNow.tv_usec/1000000.0;
fPresentationTimeOffset = ptNow - pt;
}
pt += fPresentationTimeOffset;
struct timeval presentationTime;
presentationTime.tv_sec = (unsigned)pt;
presentationTime.tv_usec = (unsigned)((pt - presentationTime.tv_sec)*1000000);
unsigned durationInMicroseconds = track->defaultDuration/1000;
if (track->haveSubframes()) {
// If this is a 'subframe', use a duration of 0 instead (unless it's the last 'subframe'):
if (fCurOffsetWithinFrame + frameSize + track->subframeSizeSize < fFrameSizesWithinBlock[fNextFrameNumberToDeliver]) {
// There's room for at least one more subframe after this, so give this subframe a duration of 0
durationInMicroseconds = 0;
}
}
if (track->defaultDuration == 0) {
// Adjust the frame duration to keep the sum of frame durations aligned with presentation times.
if (track->prevPresentationTime.tv_sec != 0) { // not the first time for this track
track->durationImbalance
+= (presentationTime.tv_sec - track->prevPresentationTime.tv_sec)*1000000
+ (presentationTime.tv_usec - track->prevPresentationTime.tv_usec);
}
int adjustment = 0;
if (track->durationImbalance > 0) {
// The duration needs to be increased.
int const adjustmentThreshold = 100000; // don't increase the duration by more than this amount (in case there's a mistake)
adjustment = track->durationImbalance > adjustmentThreshold ? adjustmentThreshold : track->durationImbalance;
} else if (track->durationImbalance < 0) {
// The duration needs to be decreased.
adjustment
= (unsigned)(-track->durationImbalance) < durationInMicroseconds ? track->durationImbalance : -(int)durationInMicroseconds;
}
durationInMicroseconds += adjustment;
track->durationImbalance -= durationInMicroseconds; // for next time
track->prevPresentationTime = presentationTime; // for next time
}
demuxedTrack->presentationTime() = presentationTime;
demuxedTrack->durationInMicroseconds() = durationInMicroseconds;
// Deliver the next block now:
if (frameSize > demuxedTrack->maxSize()) {
demuxedTrack->numTruncatedBytes() = frameSize - demuxedTrack->maxSize();
demuxedTrack->frameSize() = demuxedTrack->maxSize();
} else { // normal case
demuxedTrack->numTruncatedBytes() = 0;
demuxedTrack->frameSize() = frameSize;
}
getCommonFrameBytes(track, demuxedTrack->to(), demuxedTrack->frameSize(), demuxedTrack->numTruncatedBytes());
// Next, deliver (and/or skip) bytes from the input file:
fCurrentParseState = DELIVERING_FRAME_BYTES;
setParseState();
return True;
} while (0);
// An error occurred. Try to recover:
#ifdef DEBUG
fprintf(stderr, "deliverFrameWithinBlock(): Error parsing data; trying to recover...\n");
#endif
fCurrentParseState = LOOKING_FOR_BLOCK;
return True;
}
void MatroskaFileParser::parseBlock() {
#ifdef DEBUG
fprintf(stderr, "parsing SimpleBlock or Block\n");
#endif
do {
unsigned blockStartPos = curOffset();
// The block begins with the track number:
EBMLNumber trackNumber;
if (!parseEBMLNumber(trackNumber)) break;
fBlockTrackNumber = (unsigned)trackNumber.val();
// If this track is not being read, then skip the rest of this block, and look for another one:
if (fOurDemux->lookupDemuxedTrack(fBlockTrackNumber) == NULL) {
unsigned headerBytesSeen = curOffset() - blockStartPos;
if (headerBytesSeen < fBlockSize) {
skipBytes(fBlockSize - headerBytesSeen);
}
#ifdef DEBUG
fprintf(stderr, "\tSkipped block for unused track number %d\n", fBlockTrackNumber);
#endif
fCurrentParseState = LOOKING_FOR_BLOCK;
setParseState();
return;
}
MatroskaTrack* track = fOurFile.lookup(fBlockTrackNumber);
if (track == NULL) break; // shouldn't happen
// The next two bytes are the block's timecode (relative to the cluster timecode)
fBlockTimecode = (get1Byte()<<8)|get1Byte();
// The next byte indicates the type of 'lacing' used:
u_int8_t c = get1Byte();
c &= 0x6; // we're interested in bits 5-6 only
MatroskaLacingType lacingType = (c==0x0)?NoLacing : (c==0x02)?XiphLacing : (c==0x04)?FixedSizeLacing : EBMLLacing;
#ifdef DEBUG
fprintf(stderr, "\ttrack number %d, timecode %d (=> %f seconds), %s lacing\n", fBlockTrackNumber, fBlockTimecode, (fClusterTimecode+fBlockTimecode)*(fOurFile.fTimecodeScale/1000000000.0), (lacingType==NoLacing)?"no" : (lacingType==XiphLacing)?"Xiph" : (lacingType==FixedSizeLacing)?"fixed-size" : "EBML");
#endif
if (lacingType == NoLacing) {
fNumFramesInBlock = 1;
} else {
// The next byte tells us how many frames are present in this block
fNumFramesInBlock = get1Byte() + 1;
}
delete[] fFrameSizesWithinBlock; fFrameSizesWithinBlock = new unsigned[fNumFramesInBlock];
if (fFrameSizesWithinBlock == NULL) break;
if (lacingType == NoLacing) {
unsigned headerBytesSeen = curOffset() - blockStartPos;
if (headerBytesSeen > fBlockSize) break;
fFrameSizesWithinBlock[0] = fBlockSize - headerBytesSeen;
} else if (lacingType == FixedSizeLacing) {
unsigned headerBytesSeen = curOffset() - blockStartPos;
if (headerBytesSeen > fBlockSize) break;
unsigned frameBytesAvailable = fBlockSize - headerBytesSeen;
unsigned constantFrameSize = frameBytesAvailable/fNumFramesInBlock;
for (unsigned i = 0; i < fNumFramesInBlock; ++i) {
fFrameSizesWithinBlock[i] = constantFrameSize;
}
// If there are any bytes left over, assign them to the last frame:
fFrameSizesWithinBlock[fNumFramesInBlock-1] += frameBytesAvailable%fNumFramesInBlock;
} else { // EBML or Xiph lacing
unsigned curFrameSize = 0;
unsigned frameSizesTotal = 0;
unsigned i;
for (i = 0; i < fNumFramesInBlock-1; ++i) {
if (lacingType == EBMLLacing) {
EBMLNumber frameSize;
if (!parseEBMLNumber(frameSize)) break;
unsigned fsv = (unsigned)frameSize.val();
if (i == 0) {
curFrameSize = fsv;
} else {
// The value we read is a signed value, that's added to the previous frame size, to get the current frame size:
unsigned toSubtract = (fsv>0xFFFFFF)?0x07FFFFFF : (fsv>0xFFFF)?0x0FFFFF : (fsv>0xFF)?0x1FFF : 0x3F;
int fsv_signed = fsv - toSubtract;
curFrameSize += fsv_signed;
if ((int)curFrameSize < 0) break;
}
} else { // Xiph lacing
curFrameSize = 0;
u_int8_t c;
do {
c = get1Byte();
curFrameSize += c;
} while (c == 0xFF);
}
fFrameSizesWithinBlock[i] = curFrameSize;
frameSizesTotal += curFrameSize;
}
if (i != fNumFramesInBlock-1) break; // an error occurred within the "for" loop
// Compute the size of the final frame within the block (from the block's size, and the frame sizes already computed):)
unsigned headerBytesSeen = curOffset() - blockStartPos;
if (headerBytesSeen + frameSizesTotal > fBlockSize) break;
fFrameSizesWithinBlock[i] = fBlockSize - (headerBytesSeen + frameSizesTotal);
}
// We're done parsing headers within the block, and (as a result) we now know the sizes of all frames within the block.
// If we have 'stripped bytes' that are common to (the front of) all frames, then count them now:
if (track->headerStrippedBytesSize != 0) {
for (unsigned i = 0; i < fNumFramesInBlock; ++i) fFrameSizesWithinBlock[i] += track->headerStrippedBytesSize;
}
#ifdef DEBUG
fprintf(stderr, "\tThis block contains %d frame(s); size(s):", fNumFramesInBlock);
unsigned frameSizesTotal = 0;
for (unsigned i = 0; i < fNumFramesInBlock; ++i) {
fprintf(stderr, " %d", fFrameSizesWithinBlock[i]);
frameSizesTotal += fFrameSizesWithinBlock[i];
}
if (fNumFramesInBlock > 1) fprintf(stderr, " (total: %u)", frameSizesTotal);
fprintf(stderr, " bytes\n");
#endif
// Next, start delivering these frames:
fCurrentParseState = DELIVERING_FRAME_WITHIN_BLOCK;
fCurOffsetWithinFrame = fNextFrameNumberToDeliver = 0;
setParseState();
return;
} while (0);
// An error occurred. Try to recover:
#ifdef DEBUG
fprintf(stderr, "parseBlock(): Error parsing data; trying to recover...\n");
#endif
fCurrentParseState = LOOKING_FOR_BLOCK;
}
unsigned H264VideoStreamParser::parse() {
try {
// The stream must start with a 0x00000001:
if (!fHaveSeenFirstStartCode) {
// Skip over any input bytes that precede the first 0x00000001:
u_int32_t first4Bytes;
while ((first4Bytes = test4Bytes()) != 0x00000001) {
get1Byte(); setParseState(); // ensures that we progress over bad data
}
skipBytes(4); // skip this initial code
setParseState();
fHaveSeenFirstStartCode = True; // from now on
}
if (fOutputStartCodeSize > 0) {
// Include a start code in the output:
save4Bytes(0x00000001);
}
// Then save everything up until the next 0x00000001 (4 bytes) or 0x000001 (3 bytes), or we hit EOF.
// Also make note of the first byte, because it contains the "nal_unit_type":
if (haveSeenEOF()) {
// We hit EOF the last time that we tried to parse this data, so we know that any remaining unparsed data
// forms a complete NAL unit, and that there's no 'start code' at the end:
unsigned remainingDataSize = totNumValidBytes() - curOffset();
while (remainingDataSize > 0) {
saveByte(get1Byte());
--remainingDataSize;
}
if (!fHaveSeenFirstByteOfNALUnit) {
// There's no remaining NAL unit.
(void)get1Byte(); // forces another read, which will cause EOF to get handled for real this time
return 0;
}
#ifdef DEBUG
fprintf(stderr, "This NAL unit (%d bytes) ends with EOF\n", curFrameSize()-fOutputStartCodeSize);
#endif
} else {
u_int32_t next4Bytes = test4Bytes();
if (!fHaveSeenFirstByteOfNALUnit) {
fFirstByteOfNALUnit = next4Bytes>>24;
fHaveSeenFirstByteOfNALUnit = True;
}
while (next4Bytes != 0x00000001 && (next4Bytes&0xFFFFFF00) != 0x00000100) {
// We save at least some of "next4Bytes".
if ((unsigned)(next4Bytes&0xFF) > 1) {
// Common case: 0x00000001 or 0x000001 definitely doesn't begin anywhere in "next4Bytes", so we save all of it:
save4Bytes(next4Bytes);
skipBytes(4);
} else {
// Save the first byte, and continue testing the rest:
saveByte(next4Bytes>>24);
skipBytes(1);
}
setParseState(); // ensures forward progress
next4Bytes = test4Bytes();
}
// Assert: next4Bytes starts with 0x00000001 or 0x000001, and we've saved all previous bytes (forming a complete NAL unit).
// Skip over these remaining bytes, up until the start of the next NAL unit:
if (next4Bytes == 0x00000001) {
skipBytes(4);
} else {
skipBytes(3);
}
}
u_int8_t nal_ref_idc = (fFirstByteOfNALUnit&0x60)>>5;
u_int8_t nal_unit_type = fFirstByteOfNALUnit&0x1F;
fHaveSeenFirstByteOfNALUnit = False; // for the next NAL unit that we parse
#ifdef DEBUG
fprintf(stderr, "Parsed %d-byte NAL-unit (nal_ref_idc: %d, nal_unit_type: %d (\"%s\"))\n",
curFrameSize()-fOutputStartCodeSize, nal_ref_idc, nal_unit_type, nal_unit_type_description[nal_unit_type]);
#endif
switch (nal_unit_type) {
case 6: { // Supplemental enhancement information (SEI)
analyze_sei_data();
// Later, perhaps adjust "fPresentationTime" if we saw a "pic_timing" SEI payload??? #####
break;
}
case 7: { // Sequence parameter set
// First, save a copy of this NAL unit, in case the downstream object wants to see it:
usingSource()->saveCopyOfSPS(fStartOfFrame + fOutputStartCodeSize, fTo - fStartOfFrame - fOutputStartCodeSize);
// Parse this NAL unit to check whether frame rate information is present:
unsigned num_units_in_tick, time_scale, fixed_frame_rate_flag;
analyze_seq_parameter_set_data(num_units_in_tick, time_scale, fixed_frame_rate_flag);
if (time_scale > 0 && num_units_in_tick > 0) {
usingSource()->fFrameRate = time_scale/(2.0*num_units_in_tick);
#ifdef DEBUG
fprintf(stderr, "Set frame rate to %f fps\n", usingSource()->fFrameRate);
if (fixed_frame_rate_flag == 0) {
fprintf(stderr, "\tWARNING: \"fixed_frame_rate_flag\" was not set\n");
}
#endif
} else {
#ifdef DEBUG
fprintf(stderr, "\tThis \"Sequence Parameter Set\" NAL unit contained no frame rate information, so we use a default frame rate of %f fps\n", usingSource()->fFrameRate);
#endif
}
break;
}
case 8: { // Picture parameter set
// Save a copy of this NAL unit, in case the downstream object wants to see it:
usingSource()->saveCopyOfPPS(fStartOfFrame + fOutputStartCodeSize, fTo - fStartOfFrame - fOutputStartCodeSize);
}
}
usingSource()->setPresentationTime();
#ifdef DEBUG
unsigned long secs = (unsigned long)usingSource()->fPresentationTime.tv_sec;
unsigned uSecs = (unsigned)usingSource()->fPresentationTime.tv_usec;
fprintf(stderr, "\tPresentation time: %lu.%06u\n", secs, uSecs);
#endif
// If this NAL unit is a VCL NAL unit, we also scan the start of the next NAL unit, to determine whether this NAL unit
// ends the current 'access unit'. We need this information to figure out when to increment "fPresentationTime".
// (RTP streamers also need to know this in order to figure out whether or not to set the "M" bit.)
Boolean thisNALUnitEndsAccessUnit = False; // until we learn otherwise
if (haveSeenEOF()) {
// There is no next NAL unit, so we assume that this one ends the current 'access unit':
thisNALUnitEndsAccessUnit = True;
} else {
Boolean const isVCL = nal_unit_type <= 5 && nal_unit_type > 0; // Would need to include type 20 for SVC and MVC #####
if (isVCL) {
u_int32_t first4BytesOfNextNALUnit = test4Bytes();
u_int8_t firstByteOfNextNALUnit = first4BytesOfNextNALUnit>>24;
u_int8_t next_nal_ref_idc = (firstByteOfNextNALUnit&0x60)>>5;
u_int8_t next_nal_unit_type = firstByteOfNextNALUnit&0x1F;
if (next_nal_unit_type >= 6) {
// The next NAL unit is not a VCL; therefore, we assume that this NAL unit ends the current 'access unit':
#ifdef DEBUG
fprintf(stderr, "\t(The next NAL unit is not a VCL)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else {
// The next NAL unit is also a VCL. We need to examine it a little to figure out if it's a different 'access unit'.
// (We use many of the criteria described in section 7.4.1.2.4 of the H.264 specification.)
Boolean IdrPicFlag = nal_unit_type == 5;
Boolean next_IdrPicFlag = next_nal_unit_type == 5;
if (next_IdrPicFlag != IdrPicFlag) {
// IdrPicFlag differs in value
#ifdef DEBUG
fprintf(stderr, "\t(IdrPicFlag differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if (next_nal_ref_idc != nal_ref_idc && next_nal_ref_idc*nal_ref_idc == 0) {
// nal_ref_idc differs in value with one of the nal_ref_idc values being equal to 0
#ifdef DEBUG
fprintf(stderr, "\t(nal_ref_idc differs in value with one of the nal_ref_idc values being equal to 0)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if ((nal_unit_type == 1 || nal_unit_type == 2 || nal_unit_type == 5)
&& (next_nal_unit_type == 1 || next_nal_unit_type == 2 || next_nal_unit_type == 5)) {
// Both this and the next NAL units begin with a "slice_header".
// Parse this (for each), to get parameters that we can compare:
// Current NAL unit's "slice_header":
unsigned frame_num, pic_parameter_set_id, idr_pic_id;
Boolean field_pic_flag, bottom_field_flag;
analyze_slice_header(fStartOfFrame + fOutputStartCodeSize, fTo, nal_unit_type,
frame_num, pic_parameter_set_id, idr_pic_id, field_pic_flag, bottom_field_flag);
// Next NAL unit's "slice_header":
#ifdef DEBUG
fprintf(stderr, " Next NAL unit's slice_header:\n");
#endif
u_int8_t next_slice_header[NUM_NEXT_SLICE_HEADER_BYTES_TO_ANALYZE];
testBytes(next_slice_header, sizeof next_slice_header);
unsigned next_frame_num, next_pic_parameter_set_id, next_idr_pic_id;
Boolean next_field_pic_flag, next_bottom_field_flag;
analyze_slice_header(next_slice_header, &next_slice_header[sizeof next_slice_header], next_nal_unit_type,
next_frame_num, next_pic_parameter_set_id, next_idr_pic_id, next_field_pic_flag, next_bottom_field_flag);
if (next_frame_num != frame_num) {
// frame_num differs in value
#ifdef DEBUG
fprintf(stderr, "\t(frame_num differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if (next_pic_parameter_set_id != pic_parameter_set_id) {
// pic_parameter_set_id differs in value
#ifdef DEBUG
fprintf(stderr, "\t(pic_parameter_set_id differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if (next_field_pic_flag != field_pic_flag) {
// field_pic_flag differs in value
#ifdef DEBUG
fprintf(stderr, "\t(field_pic_flag differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if (next_bottom_field_flag != bottom_field_flag) {
// bottom_field_flag differs in value
#ifdef DEBUG
fprintf(stderr, "\t(bottom_field_flag differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
} else if (next_IdrPicFlag == 1 && next_idr_pic_id != idr_pic_id) {
// IdrPicFlag is equal to 1 for both and idr_pic_id differs in value
// Note: We already know that IdrPicFlag is the same for both.
#ifdef DEBUG
fprintf(stderr, "\t(IdrPicFlag is equal to 1 for both and idr_pic_id differs in value)\n");
#endif
thisNALUnitEndsAccessUnit = True;
}
}
}
}
}
if (thisNALUnitEndsAccessUnit) {
#ifdef DEBUG
fprintf(stderr, "*****This NAL unit ends the current access unit*****\n");
#endif
usingSource()->fPictureEndMarker = True;
++usingSource()->fPictureCount;
// Note that the presentation time for the next NAL unit will be different:
struct timeval& nextPT = usingSource()->fNextPresentationTime; // alias
nextPT = usingSource()->fPresentationTime;
double nextFraction = nextPT.tv_usec/1000000.0 + 1/usingSource()->fFrameRate;
unsigned nextSecsIncrement = (long)nextFraction;
nextPT.tv_sec += (long)nextSecsIncrement;
nextPT.tv_usec = (long)((nextFraction - nextSecsIncrement)*1000000);
}
setParseState();
return curFrameSize();
} catch (int /*e*/) {
unsigned MPEG1or2VideoStreamParser::parseGOPHeader(Boolean haveSeenStartCode)
{
// First check whether we should insert a previously-saved
// 'video_sequence_header' here:
if (needToUseSavedVSH()) return useSavedVSH();
#ifdef DEBUG
fprintf(stderr, "parsing GOP header\n");
#endif
unsigned first4Bytes;
if (!haveSeenStartCode)
{
while ((first4Bytes = test4Bytes()) != GROUP_START_CODE)
{
#ifdef DEBUG
fprintf(stderr, "ignoring non GOP start code: 0x%08x\n", first4Bytes);
#endif
get1Byte();
setParseState(PARSING_GOP_HEADER);
// ensures we progress over bad data
}
first4Bytes = get4Bytes();
}
else
{
// We've already seen the GROUP_START_CODE
first4Bytes = GROUP_START_CODE;
}
save4Bytes(first4Bytes);
// Next, extract the (25-bit) time code from the next 4 bytes:
unsigned next4Bytes = get4Bytes();
unsigned time_code = (next4Bytes & 0xFFFFFF80) >> (32 - 25);
#if defined(DEBUG) || defined(DEBUG_TIMESTAMPS)
Boolean drop_frame_flag = (time_code & 0x01000000) != 0;
#endif
unsigned time_code_hours = (time_code & 0x00F80000) >> 19;
unsigned time_code_minutes = (time_code & 0x0007E000) >> 13;
unsigned time_code_seconds = (time_code & 0x00000FC0) >> 6;
unsigned time_code_pictures = (time_code & 0x0000003F);
#if defined(DEBUG) || defined(DEBUG_TIMESTAMPS)
fprintf(stderr, "time_code: 0x%07x, drop_frame %d, hours %d, minutes %d, seconds %d, pictures %d\n", time_code, drop_frame_flag, time_code_hours, time_code_minutes, time_code_seconds, time_code_pictures);
#endif
#ifdef DEBUG
Boolean closed_gop = (next4Bytes & 0x00000040) != 0;
Boolean broken_link = (next4Bytes & 0x00000020) != 0;
fprintf(stderr, "closed_gop: %d, broken_link: %d\n", closed_gop, broken_link);
#endif
// Now, copy all bytes that we see, up until we reach a PICTURE_START_CODE:
do
{
saveToNextCode(next4Bytes);
}
while (next4Bytes != PICTURE_START_CODE);
// Record the time code:
usingSource()->setTimeCode(time_code_hours, time_code_minutes,
time_code_seconds, time_code_pictures,
fPicturesSinceLastGOP);
fPicturesSinceLastGOP = 0;
// Compute this frame's timestamp:
usingSource()->computePresentationTime(0);
setParseState(PARSING_PICTURE_HEADER);
return curFrameSize();
}
