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Prevent updating tkhd atom to version 1 for compatibility

This commit is contained in:
Martchus 2019-04-19 21:12:35 +02:00
parent 8588edaa2e
commit 48166bde9e
1 changed files with 30 additions and 9 deletions
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39
mp4/mp4track.cpp
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@ -435,12 +435,15 @@ TrackHeaderInfo Mp4Track::verifyPresentTrackHeader() const
// determine required size
info.requiredSize = m_tkhdAtom->dataSize() + 8;
if (info.version == 0) {
// add 12 byte to size if the existing version is 0 because we always write version 1 which takes 12 byte more space
// -> add 12 byte to size if update from version 0 to version 1 is required (which needs 12 byte more)
if ((info.version == 0)
&& (static_cast<std::uint64_t>((m_creationTime - startDate).totalSeconds()) > numeric_limits<std::uint32_t>::max()
|| static_cast<std::uint64_t>((m_modificationTime - startDate).totalSeconds()) > numeric_limits<std::uint32_t>::max()
|| static_cast<std::uint64_t>(m_duration.totalSeconds() * m_timeScale) > numeric_limits<std::uint32_t>::max())) {
info.requiredSize += 12;
}
if (info.requiredSize > numeric_limits<uint32>::max()) {
// add 8 byte to the size because it must be denoted using a 64-bit integer
// -> add 8 byte to the size because it must be denoted using a 64-bit integer
if (info.requiredSize > numeric_limits<std::uint32_t>::max()) {
info.requiredSize += 8;
}
return info;
@ -1192,9 +1195,17 @@ void Mp4Track::makeTrackHeader(Diagnostics &diag)
writer().writeUInt32BE(Mp4AtomIds::TrackHeader);
}
// determine time-related values and version
const auto creationTime = static_cast<std::uint64_t>((m_creationTime - startDate).totalSeconds());
const auto modificationTime = static_cast<std::uint64_t>((m_modificationTime - startDate).totalSeconds());
const auto duration = static_cast<std::uint64_t>(m_duration.totalSeconds() * m_timeScale);
const std::uint8_t version = (info.version == 0) && (creationTime > numeric_limits<std::uint32_t>::max()
|| modificationTime > numeric_limits<std::uint32_t>::max()
|| duration > numeric_limits<std::uint32_t>::max()) ? 1 : info.version;
// make version and flags
writer().writeByte(1);
uint32 flags = 0;
writer().writeByte(version);
std::uint32_t flags = 0;
if (m_enabled) {
flags |= 0x000001;
}
@ -1207,13 +1218,22 @@ void Mp4Track::makeTrackHeader(Diagnostics &diag)
writer().writeUInt24BE(flags);
// make creation and modification time
writer().writeUInt64BE(static_cast<uint64>((m_creationTime - startDate).totalSeconds()));
writer().writeUInt64BE(static_cast<uint64>((m_modificationTime - startDate).totalSeconds()));
if (version != 0) {
writer().writeUInt64BE(creationTime);
writer().writeUInt64BE(modificationTime);
} else {
writer().writeUInt32BE(static_cast<std::uint32_t>(creationTime));
writer().writeUInt32BE(static_cast<std::uint32_t>(modificationTime));
}
// make track ID and duration
writer().writeUInt32BE(static_cast<uint32>(m_id));
writer().writeUInt32BE(0); // reserved
writer().writeUInt64BE(static_cast<uint64>(m_duration.totalSeconds() * m_timeScale));
if (version != 0) {
writer().writeUInt64BE(duration);
} else {
writer().writeUInt32BE(static_cast<std::uint32_t>(duration));
}
writer().writeUInt32BE(0); // reserved
writer().writeUInt32BE(0); // reserved
@ -1228,6 +1248,7 @@ void Mp4Track::makeTrackHeader(Diagnostics &diag)
}
} else {
// write default values
diag.emplace_back(DiagLevel::Warning, "Writing some default values because the existing tkhd atom is truncated.", "making tkhd atom");
writer().writeInt16BE(0); // layer
writer().writeInt16BE(0); // alternate group
writer().writeFixed8BE(1.0); // volume (fixed 8.8 - 2 byte)