采用串联多个android's MP4音频文件MediaMuxer [英] Concatenate multiple mp4 audio files using android´s MediaMuxer
问题描述
我试图连接多个MP4音频文件（每个只含有一个音轨，所有记录有相同MediaRecorder和相同的参数）为一个使用以下功能：
I am trying to concatenate multiple mp4 audio files (each containing only one audio track, all recorded with the same MediaRecorder and the same parameters) into one using the following function:
@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;
}
在code编译和运行，但玩生成的文件的时候，我听到只有第一个文件的内容。我不明白我在做什么错了。
The code compiles and runs, but when playing the resulting file, I hear only the contents of the first file. I do not see what I am doing wrong.
不过，马龙向我指出了方向之后，有什么奇怪的，我从MediaMuxer获得的消息。在这里，他们是：
However, after Marlon pointed me to that direction, there is something strange about the messages I am getting from the MediaMuxer. Here they are:
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
似乎从第一文件复制数据之后，MPEG4Writer（为什么不MediaMuxer？）停止轨道和不写入更多的数据。我怎样才能prevent是什么？我必须直接操纵头，如果是这样，怎么样？
It seems that after copying data from the first file, MPEG4Writer (why not MediaMuxer?) stops the track and does not write further data. How can I prevent that? Do I have to manipulate the headers directly, and if so, how?
任何帮助将是AP preciated。
Any help would be appreciated.
最好的问候，
基督教
推荐答案
在形式上不能加入2个连接codeD音频轨道：每个轨道可以带它们存储在不同的头参数codeD。可以肯定，如果这两个文件是由相同的EN codeR \\合并器，相同的编码参数和头都创造了相等它可以工作，但它是相当严格的限制。
至于我看到你在合并器设置音频格式（包含头）为音轨从第一个文件格式化。所以，如果第2个文件中的音频格式不同，它可以导致不同种类导致不正确第二个文件中的音频错误。
Formally you can't join 2 encoded audio tracks: each track could be encoded with different parameters which are stored in headers. For sure if both files were created by the same encoder\muxer, same encoding parameters and both headers are equal it can work, but it is rather strict limitation. As far as i see you set audio format (it contains headers) to audio track in muxer to format from 1st file. So if 2nd file audio format differs it can cause different sorts of errors resulting in not correct second file audio.
请尽量把一个源文件两次DST文件，第一和第二。如果它的工作原理 - 比这个问题是在头。如果没有 - 然后在其他地方，我觉得
Please try to put one source file twice to dst file, as first and second. If it works - than the problem is in headers. If not - then somewhere else, i think.
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