status_t MatroskaSource::read(
MediaBuffer **out, const ReadOptions *options) {
*out = NULL;
int64_t seekTimeUs;
ReadOptions::SeekMode mode;
if (options && options->getSeekTo(&seekTimeUs, &mode)) {
mBlockIter.seek(seekTimeUs);
}
if (mBlockIter.eos()) {
return ERROR_END_OF_STREAM;
}
const mkvparser::Block *block = mBlockIter.block();
size_t size = block->GetSize();
int64_t timeUs = mBlockIter.blockTimeUs();
MediaBuffer *buffer = new MediaBuffer(size + 2);
buffer->meta_data()->setInt64(kKeyTime, timeUs);
buffer->meta_data()->setInt32(kKeyIsSyncFrame, block->IsKey());
long res = block->Read(
mExtractor->mReader, (unsigned char *)buffer->data() + 2);
if (res != 0) {
return ERROR_END_OF_STREAM;
}
buffer->set_range(2, size);
if (mType == AVC) {
CHECK(size >= 2);
uint8_t *data = (uint8_t *)buffer->data();
unsigned NALsize = data[2] << 8 | data[3];
CHECK_EQ(size, NALsize + 2);
memcpy(data, "\x00\x00\x00\x01", 4);
buffer->set_range(0, size + 2);
} else if (mType == AAC) {
// There's strange junk at the beginning...
const uint8_t *data = (const uint8_t *)buffer->data() + 2;
size_t offset = 0;
while (offset < size && data[offset] != 0x21) {
++offset;
}
buffer->set_range(2 + offset, size - offset);
}
*out = buffer;
#if 0
hexdump((const uint8_t *)buffer->data() + buffer->range_offset(),
buffer->range_length());
#endif
mBlockIter.advance();
return OK;
}
