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Apply MP4 track meta-data also when not writing chunk-by-chunk

This commit is contained in:
Martchus 2017-06-17 00:31:35 +02:00
parent 03383a18b9
commit f323061767
3 changed files with 78 additions and 46 deletions
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36
mp4/mp4container.cpp
View File

@ -393,11 +393,7 @@ void Mp4Container::internalMakeFile()
}
break;
case Mp4AtomIds::Track:
// add size of track atoms only if not writing chunk-by-chunk (otherwise sizes are added separately)
if(!writeChunkByChunk) {
movieAtomSize += level1Atom->totalSize();
level1Atom->makeBuffer();
}
// ignore track atoms here; they are added separately
break;
default:
// add size of unknown childs of the movie atom
@ -413,12 +409,9 @@ void Mp4Container::internalMakeFile()
movieAtomSize += userDataAtomSize;
}
// add size of track atoms when writing chunk-by-chunk
if(writeChunkByChunk) {
// note: Mp4Track API has to be changed when Mp4Track::makeTrack() gets a real implementation.
for(const auto &track : tracks()) {
movieAtomSize += track->requiredSize();
}
// add size of track atoms
for(const auto &track : tracks()) {
movieAtomSize += track->requiredSize();
}
// add header size
@ -555,6 +548,11 @@ calculatePadding:
// TODO: reduce code duplication
} else { // !rewriteRequired
// ensure everything to make track atoms is buffered before altering the source file
for(const auto &track : tracks()) {
track->bufferTrackAtoms();
}
// reopen original file to ensure it is opened for writing
try {
fileInfo().close();
@ -596,12 +594,9 @@ calculatePadding:
// -> write movie atom header
Mp4Atom::makeHeader(movieAtomSize, Mp4AtomIds::Movie, outputWriter);
// -> write track atoms (only if writing chunk-by-chunk; otherwise track atoms are written with other children)
if(writeChunkByChunk) {
// note: Mp4Track API has to be changed when Mp4Track::makeTrack() gets a real implementation.
for(auto &track : tracks()) {
track->makeTrack();
}
// -> write track atoms
for(auto &track : tracks()) {
track->makeTrack();
}
// -> write other movie atom children
@ -609,13 +604,8 @@ calculatePadding:
for(level1Atom = level0Atom->firstChild(); level1Atom; level1Atom = level1Atom->nextSibling()) {
switch(level1Atom->id()) {
case Mp4AtomIds::UserData:
break;
case Mp4AtomIds::Track:
// write buffered data
if(!writeChunkByChunk) {
level1Atom->copyBuffer(outputStream);
level1Atom->discardBuffer();
}
// track and user data atoms are written separately
break;
default:
// write buffered data

83
mp4/mp4track.cpp
View File

@ -928,10 +928,47 @@ void Mp4Track::addInfo(const AvcConfiguration &avcConfig, AbstractTrack &track)
}
/*!
* \brief Buffers all atoms required by the makeTrack() method.
*
* This allows to invoke makeTrack() also when the input stream is going to be
* modified (eg. to apply changed tags without rewriting the file).
*/
void Mp4Track::bufferTrackAtoms()
{
if(m_tkhdAtom) {
m_tkhdAtom->makeBuffer();
}
if(Mp4Atom *trefAtom = m_trakAtom->childById(Mp4AtomIds::TrackReference)) {
trefAtom->makeBuffer();
}
if(Mp4Atom *edtsAtom = m_trakAtom->childById(Mp4AtomIds::Edit)) {
edtsAtom->makeBuffer();
}
if(m_minfAtom) {
if(Mp4Atom *vmhdAtom = m_minfAtom->childById(Mp4AtomIds::VideoMediaHeader)) {
vmhdAtom->makeBuffer();
}
if(Mp4Atom *smhdAtom = m_minfAtom->childById(Mp4AtomIds::SoundMediaHeader)) {
smhdAtom->makeBuffer();
}
if(Mp4Atom *hmhdAtom = m_minfAtom->childById(Mp4AtomIds::HintMediaHeader)) {
hmhdAtom->makeBuffer();
}
if(Mp4Atom *nmhdAtom = m_minfAtom->childById(Mp4AtomIds::NullMediaHeaderBox)) {
nmhdAtom->makeBuffer();
}
if(Mp4Atom *dinfAtom = m_minfAtom->childById(Mp4AtomIds::DataInformation)) {
dinfAtom->makeBuffer();
}
if(Mp4Atom *stblAtom = m_minfAtom->childById(Mp4AtomIds::SampleTable)) {
stblAtom->makeBuffer();
}
}
}
/*!
* \brief Returns the number of bytes written when calling makeTrack().
* \todo Get rid of const_cast. This is currently required because GenericFileElement::childById() is
* not const.
*/
uint64 Mp4Track::requiredSize() const
{
@ -978,9 +1015,12 @@ uint64 Mp4Track::requiredSize() const
}
/*!
* \brief Makes the track entry ("trak"-atom) for the track. The data is written to the assigned output stream
* at the current position.
* \remarks Currently the "trak"-atom from the source file is just copied to the output stream.
* \brief Makes the track entry ("trak"-atom) for the track.
*
* The data is written to the assigned output stream at the current position. Note that this method
* uses the assigned input stream to copy some parts from the source file. Hence the input stream must
* still be valid when calling this method. To avoid this limitation call bufferTrackAtoms() before
* invalidating the input stream.
*/
void Mp4Track::makeTrack()
{
@ -992,11 +1032,11 @@ void Mp4Track::makeTrack()
makeTrackHeader();
// write tref atom (if one exists)
if(Mp4Atom *trefAtom = trakAtom().childById(Mp4AtomIds::TrackReference)) {
trefAtom->copyEntirely(outputStream());
trefAtom->copyPreferablyFromBuffer(outputStream());
}
// write edts atom (if one exists)
if(Mp4Atom *edtsAtom = trakAtom().childById(Mp4AtomIds::Edit)) {
edtsAtom->copyEntirely(outputStream());
edtsAtom->copyPreferablyFromBuffer(outputStream());
}
// write mdia atom
makeMedia();
@ -1033,17 +1073,21 @@ void Mp4Track::makeTrackHeader()
writer().writeUInt32BE(0); // reserved
if(m_tkhdAtom) {
// use existing values
char buffer[48];
m_istream->seekg(m_tkhdAtom->startOffset() + 52);
m_istream->read(buffer, sizeof(buffer));
m_ostream->write(buffer, sizeof(buffer));
if(m_tkhdAtom->buffer()) {
m_ostream->write(m_tkhdAtom->buffer().get() + 52, 48);
} else {
char buffer[48];
m_istream->seekg(m_tkhdAtom->startOffset() + 52);
m_istream->read(buffer, sizeof(buffer));
m_ostream->write(buffer, sizeof(buffer));
}
} else {
// write default values
writer().writeInt16BE(0); // layer
writer().writeInt16BE(0); // alternate group
writer().writeFixed8BE(1.0); // volume
writer().writeUInt16BE(0); // reserved
for(int32 value : {0x00010000,0,0,0,0x00010000,0,0,0,0x40000000}) { // unity matrix
for(const int32 value : {0x00010000,0,0,0,0x00010000,0,0,0,0x40000000}) { // unity matrix
writer().writeInt32BE(value);
}
writer().writeFixed16BE(1.0); // width
@ -1126,23 +1170,23 @@ void Mp4Track::makeMediaInfo()
if(m_minfAtom) {
// copy existing vmhd atom
if(Mp4Atom *vmhdAtom = m_minfAtom->childById(Mp4AtomIds::VideoMediaHeader)) {
vmhdAtom->copyEntirely(outputStream());
vmhdAtom->copyPreferablyFromBuffer(outputStream());
}
// copy existing smhd atom
if(Mp4Atom *smhdAtom = m_minfAtom->childById(Mp4AtomIds::SoundMediaHeader)) {
smhdAtom->copyEntirely(outputStream());
smhdAtom->copyPreferablyFromBuffer(outputStream());
}
// copy existing hmhd atom
if(Mp4Atom *hmhdAtom = m_minfAtom->childById(Mp4AtomIds::HintMediaHeader)) {
hmhdAtom->copyEntirely(outputStream());
hmhdAtom->copyPreferablyFromBuffer(outputStream());
}
// copy existing nmhd atom
if(Mp4Atom *nmhdAtom = m_minfAtom->childById(Mp4AtomIds::NullMediaHeaderBox)) {
nmhdAtom->copyEntirely(outputStream());
nmhdAtom->copyPreferablyFromBuffer(outputStream());
}
// copy existing dinf atom
if(Mp4Atom *dinfAtom = m_minfAtom->childById(Mp4AtomIds::DataInformation)) {
dinfAtom->copyEntirely(outputStream());
dinfAtom->copyPreferablyFromBuffer(outputStream());
dinfAtomWritten = true;
}
}
@ -1166,13 +1210,12 @@ void Mp4Track::makeMediaInfo()
bool stblAtomWritten = false;
if(m_minfAtom) {
if(Mp4Atom *stblAtom = m_minfAtom->childById(Mp4AtomIds::SampleTable)) {
stblAtom->copyEntirely(outputStream());
stblAtom->copyPreferablyFromBuffer(outputStream());
stblAtomWritten = true;
}
}
if(!stblAtomWritten) {
addNotification(NotificationType::Critical, "Unable to make stbl atom from scratch.", "making stbl atom");
throw NotImplementedException();
addNotification(NotificationType::Critical, "Source track does not contain mandatory stbl atom and the tagparser lib is unable to make one from scratch.", "making stbl atom");
}
// write size (of minf atom)
Mp4Atom::seekBackAndWriteAtomSize(outputStream(), minfStartOffset);

5
mp4/mp4track.h
View File

@ -144,8 +144,9 @@ public:
std::vector<uint64> readChunkSizes();
// methods to make the track header
void makeTrack();
void bufferTrackAtoms();
uint64 requiredSize() const;
void makeTrack();
void makeTrackHeader();
void makeMedia();
void makeMediaInfo();
@ -177,8 +178,6 @@ private:
Mp4Atom *m_stscAtom;
Mp4Atom *m_stcoAtom;
Mp4Atom *m_stszAtom;
//Mp4Atom *m_codecConfigAtom;
//Mp4Atom *m_esDescAtom;
uint16 m_framesPerSample;
std::vector<uint32> m_sampleSizes;
unsigned int m_chunkOffsetSize;