次の関数を使用して、複数の mp4 オーディオ ファイル (それぞれが 1 つのオーディオ トラックのみを含み、すべて同じ MediaRecorder と同じパラメーターで記録されている) を 1 つに連結しようとしています。
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
public static boolean concatenateFiles(File dst, File... sources) {
if ((sources == null) || (sources.length == 0)) {
return false;
}
boolean result;
MediaExtractor extractor = null;
MediaMuxer muxer = null;
try {
// Set up MediaMuxer for the destination.
muxer = new MediaMuxer(dst.getPath(), MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
// Copy the samples from MediaExtractor to MediaMuxer.
boolean sawEOS = false;
int bufferSize = MAX_SAMPLE_SIZE;
int frameCount = 0;
int offset = 100;
ByteBuffer dstBuf = ByteBuffer.allocate(bufferSize);
BufferInfo bufferInfo = new BufferInfo();
long timeOffsetUs = 0;
int dstTrackIndex = -1;
for (int fileIndex = 0; fileIndex < sources.length; fileIndex++) {
int numberOfSamplesInSource = getNumberOfSamples(sources[fileIndex]);
if (VERBOSE) {
Log.d(TAG, String.format("Source file: %s", sources[fileIndex].getPath()));
}
// Set up MediaExtractor to read from the source.
extractor = new MediaExtractor();
extractor.setDataSource(sources[fileIndex].getPath());
// Set up the tracks.
SparseIntArray indexMap = new SparseIntArray(extractor.getTrackCount());
for (int i = 0; i < extractor.getTrackCount(); i++) {
extractor.selectTrack(i);
MediaFormat format = extractor.getTrackFormat(i);
if (dstTrackIndex < 0) {
dstTrackIndex = muxer.addTrack(format);
muxer.start();
}
indexMap.put(i, dstTrackIndex);
}
long lastPresentationTimeUs = 0;
int currentSample = 0;
while (!sawEOS) {
bufferInfo.offset = offset;
bufferInfo.size = extractor.readSampleData(dstBuf, offset);
if (bufferInfo.size < 0) {
sawEOS = true;
bufferInfo.size = 0;
timeOffsetUs += (lastPresentationTimeUs + APPEND_DELAY);
}
else {
lastPresentationTimeUs = extractor.getSampleTime();
bufferInfo.presentationTimeUs = extractor.getSampleTime() + timeOffsetUs;
bufferInfo.flags = extractor.getSampleFlags();
int trackIndex = extractor.getSampleTrackIndex();
if ((currentSample < numberOfSamplesInSource) || (fileIndex == sources.length - 1)) {
muxer.writeSampleData(indexMap.get(trackIndex), dstBuf, bufferInfo);
}
extractor.advance();
frameCount++;
currentSample++;
if (VERBOSE) {
Log.d(TAG, "Frame (" + frameCount + ") " +
"PresentationTimeUs:" + bufferInfo.presentationTimeUs +
" Flags:" + bufferInfo.flags +
" TrackIndex:" + trackIndex +
" Size(KB) " + bufferInfo.size / 1024);
}
}
}
extractor.release();
extractor = null;
}
result = true;
}
catch (IOException e) {
result = false;
}
finally {
if (extractor != null) {
extractor.release();
}
if (muxer != null) {
muxer.stop();
muxer.release();
}
}
return result;
}
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
public static int getNumberOfSamples(File src) {
MediaExtractor extractor = new MediaExtractor();
int result;
try {
extractor.setDataSource(src.getPath());
extractor.selectTrack(0);
result = 0;
while (extractor.advance()) {
result ++;
}
}
catch(IOException e) {
result = -1;
}
finally {
extractor.release();
}
return result;
}
コードはコンパイルされて実行されますが、結果のファイルを再生すると、最初のファイルの内容しか聞こえません。私が間違っていることはわかりません。
しかし、Marlon が私にその方向を示した後、MediaMuxer から受け取っているメッセージに奇妙な点があります。どうぞ：
05-04 15:30:01.869: D/MediaMuxerTest(5455): Source file: /storage/emulated/0/Android/data/de.absprojects.catalogizer/files/copy.mp4
05-04 15:30:01.889: D/QCUtils(5455): extended extractor not needed, return default
05-04 15:30:01.889: I/MPEG4Writer(5455): limits: 2147483647/0 bytes/us, bit rate: -1 bps and the estimated moov size 3072 bytes
05-04 15:30:01.889: I/MPEG4Writer(5455): setStartTimestampUs: 0
05-04 15:30:01.889: I/MPEG4Writer(5455): Earliest track starting time: 0
05-04 15:30:01.889: D/MediaMuxerTest(5455): Frame (1) PresentationTimeUs:0 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.889: D/MediaMuxerTest(5455): Frame (2) PresentationTimeUs:23219 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.889: D/MediaMuxerTest(5455): Frame (3) PresentationTimeUs:46439 Flags:1 TrackIndex:0 Size(KB) 0
[...]
05-04 15:30:01.959: D/MediaMuxerTest(5455): Frame (117) PresentationTimeUs:2693401 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.959: D/MediaMuxerTest(5455): Frame (118) PresentationTimeUs:2716621 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.959: D/MediaMuxerTest(5455): Frame (119) PresentationTimeUs:2739841 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.959: D/MediaMuxerTest(5455): Frame (120) PresentationTimeUs:2763061 Flags:1 TrackIndex:0 Size(KB) 0
05-04 15:30:01.979: D/QCUtils(5455): extended extractor not needed, return default
05-04 15:30:01.979: D/MediaMuxerTest(5455): Source file: /storage/emulated/0/Android/data/de.absprojects.catalogizer/files/temp.mp4
05-04 15:30:01.979: I/MPEG4Writer(5455): Received total/0-length (120/0) buffers and encoded 120 frames. - audio
05-04 15:30:01.979: I/MPEG4Writer(5455): Audio track drift time: 0 us
05-04 15:30:01.979: D/MPEG4Writer(5455): Setting Audio track to done
05-04 15:30:01.979: D/MPEG4Writer(5455): Stopping Audio track
05-04 15:30:01.979: D/MPEG4Writer(5455): Stopping Audio track source
05-04 15:30:01.979: D/MPEG4Writer(5455): Audio track stopped
05-04 15:30:01.979: D/MPEG4Writer(5455): Stopping writer thread
05-04 15:30:01.979: D/MPEG4Writer(5455): 0 chunks are written in the last batch
05-04 15:30:01.979: D/MPEG4Writer(5455): Writer thread stopped
05-04 15:30:01.979: D/MPEG4Writer(5455): Stopping Audio track
05-04 15:30:01.979: E/MPEG4Writer(5455): Stop() called but track is not started
05-04 15:30:01.999: D/QCUtils(5455): extended extractor not needed, return default
05-04 15:30:01.999: D/copyOriginalFile()(5455): 120 samples in original file
05-04 15:30:02.009: D/QCUtils(5455): extended extractor not needed, return default
05-04 15:30:02.019: D/copyOriginalFile()(5455): 120 samples in copied file
05-04 15:30:02.019: W/MediaRecorder(5455): mediarecorder went away with unhandled events
05-04 15:30:02.099: I/dalvikvm(5455): Jit: resizing JitTable from 4096 to 8192
最初のファイルからデータをコピーした後、MPEG4Writer (なぜ MediaMuxer ではないのですか?) はトラックを停止し、それ以上データを書き込まないようです。どうすればそれを防ぐことができますか? ヘッダーを直接操作する必要がありますか? もしそうなら、どのようにしますか?
どんな助けでも大歓迎です。
よろしくお願いします、
キリスト教徒