status_t MPEG4Writer::start() {
if (mFile == NULL) {
return UNKNOWN_ERROR;
}
beginBox("ftyp");
writeFourcc("isom");
writeInt32(0);
writeFourcc("isom");
endBox();
mMdatOffset = mOffset;
write("\x00\x00\x00\x01mdat????????", 16);
for (List<Track *>::iterator it = mTracks.begin();
it != mTracks.end(); ++it) {
status_t err = (*it)->start();
if (err != OK) {
for (List<Track *>::iterator it2 = mTracks.begin();
it2 != it; ++it2) {
(*it2)->stop();
}
return err;
}
}
return OK;
}
/*
* Geodata is stored according to ISO-6709 standard.
*/
void MPEG4Writer::writeGeoDataBox() {
beginBox("\xA9xyz");
/*
* For historical reasons, any user data start
* with "\0xA9", must be followed by its assoicated
* language code.
* 0x0012: text string length
* 0x15c7: lang (locale) code: en
*/
writeInt32(0x001215c7);
writeLatitude(mLatitudex10000);
writeLongitude(mLongitudex10000);
writeInt8(0x2F);
endBox();
}
void MPEG4Writer::stop() {
if (mFile == NULL) {
return;
}
int64_t max_duration = 0;
for (List<Track *>::iterator it = mTracks.begin();
it != mTracks.end(); ++it) {
(*it)->stop();
int64_t duration = (*it)->getDuration();
if (duration > max_duration) {
max_duration = duration;
}
}
// Fix up the size of the 'mdat' chunk.
fseek(mFile, mMdatOffset + 8, SEEK_SET);
int64_t size = mOffset - mMdatOffset;
size = hton64(size);
fwrite(&size, 1, 8, mFile);
fseek(mFile, mOffset, SEEK_SET);
time_t now = time(NULL);
beginBox("moov");
beginBox("mvhd");
writeInt32(0); // version=0, flags=0
writeInt32(now); // creation time
writeInt32(now); // modification time
writeInt32(1000); // timescale
writeInt32(max_duration);
writeInt32(0x10000); // rate
writeInt16(0x100); // volume
writeInt16(0); // reserved
writeInt32(0); // reserved
writeInt32(0); // reserved
writeInt32(0x10000); // matrix
writeInt32(0);
writeInt32(0);
writeInt32(0);
writeInt32(0x10000);
writeInt32(0);
writeInt32(0);
writeInt32(0);
writeInt32(0x40000000);
writeInt32(0); // predefined
writeInt32(0); // predefined
writeInt32(0); // predefined
writeInt32(0); // predefined
writeInt32(0); // predefined
writeInt32(0); // predefined
writeInt32(mTracks.size() + 1); // nextTrackID
endBox(); // mvhd
int32_t id = 1;
for (List<Track *>::iterator it = mTracks.begin();
it != mTracks.end(); ++it, ++id) {
(*it)->writeTrackHeader(id);
}
endBox(); // moov
CHECK(mBoxes.empty());
fclose(mFile);
mFile = NULL;
}