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最近工作中遇到了音视频处理的需求，Android下音视频合成，在当前调研方案中主要有三大类方法：MediaMux硬解码，mp4parser，FFmepg。三种方法均可实现，但是也有不同的局限和问题，先将实现和问题记录于此，便于之后的总结学习。下面话不多说了，来一起看看详细的介绍吧。
方法一（Fail）
利用MediaMux实现音视频的合成。
效果：可以实现音视频的合并，利用Android原生的VideoView和SurfaceView播放正常，大部分的播放器也播放正常，但是，但是，在上传Youtube就会出现问题：音频不连续，分析主要是上传Youtube时会被再次的压缩，可能在压缩的过程中出现音频的帧率出现问题。
分析：在MediaCodec.BufferInfo的处理中，时间戳presentationTimeUs出现问题，导致Youtube的压缩造成音频的紊乱。
public static void muxVideoAndAudio(String videoPath, String audioPath, String muxPath) {
try {
MediaExtractor videoExtractor = new MediaExtractor();
videoExtractor.setDataSource(videoPath);
MediaFormat videoFormat = null;
int videoTrackIndex = -1;
int videoTrackCount = videoExtractor.getTrackCount();
for (int i = 0; i < videoTrackCount; i++) {
videoFormat = videoExtractor.getTrackFormat(i);
String mimeType = videoFormat.getString(MediaFormat.KEY_MIME);
if (mimeType.startsWith("video/")) {
videoTrackIndex = i;
break;
}
}
MediaExtractor audioExtractor = new MediaExtractor();
audioExtractor.setDataSource(audioPath);
MediaFormat audioFormat = null;
int audioTrackIndex = -1;
int audioTrackCount = audioExtractor.getTrackCount();
for (int i = 0; i < audioTrackCount; i++) {
audioFormat = audioExtractor.getTrackFormat(i);
String mimeType = audioFormat.getString(MediaFormat.KEY_MIME);
if (mimeType.startsWith("audio/")) {
audioTrackIndex = i;
break;
}
}
videoExtractor.selectTrack(videoTrackIndex);
audioExtractor.selectTrack(audioTrackIndex);
MediaCodec.BufferInfo videoBufferInfo = new MediaCodec.BufferInfo();
MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo();
MediaMuxer mediaMuxer = new MediaMuxer(muxPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
int writeVideoTrackIndex = mediaMuxer.addTrack(videoFormat);
int writeAudioTrackIndex = mediaMuxer.addTrack(audioFormat);
mediaMuxer.start();
ByteBuffer byteBuffer = ByteBuffer.allocate(500 * 1024);
long sampleTime = 0;
{
videoExtractor.readSampleData(byteBuffer, 0);
if (videoExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) {
videoExtractor.advance();
}
videoExtractor.readSampleData(byteBuffer, 0);
long secondTime = videoExtractor.getSampleTime();
videoExtractor.advance();
long thirdTime = videoExtractor.getSampleTime();
sampleTime = Math.abs(thirdTime - secondTime);
}
videoExtractor.unselectTrack(videoTrackIndex);
videoExtractor.selectTrack(videoTrackIndex);
while (true) {
int readVideoSampleSize = videoExtractor.readSampleData(byteBuffer, 0);
if (readVideoSampleSize < 0) {
break;
}
videoBufferInfo.size = readVideoSampleSize;
videoBufferInfo.presentationTimeUs += sampleTime;
videoBufferInfo.offset = 0;
//noinspection WrongConstant
videoBufferInfo.flags = MediaCodec.BUFFER_FLAG_SYNC_FRAME;//videoExtractor.getSampleFlags()
mediaMuxer.writeSampleData(writeVideoTrackIndex, byteBuffer, videoBufferInfo);
videoExtractor.advance();
}
while (true) {
int readAudioSampleSize = audioExtractor.readSampleData(byteBuffer, 0);
if (readAudioSampleSize < 0) {
break;
}
audioBufferInfo.size = readAudioSampleSize;
audioBufferInfo.presentationTimeUs += sampleTime;
audioBufferInfo.offset = 0;
//noinspection WrongConstant
audioBufferInfo.flags = MediaCodec.BUFFER_FLAG_SYNC_FRAME;// videoExtractor.getSampleFlags()
mediaMuxer.writeSampleData(writeAudioTrackIndex, byteBuffer, audioBufferInfo);
audioExtractor.advance();
}
mediaMuxer.stop();
mediaMuxer.release();
videoExtractor.release();
audioExtractor.release();
} catch (IOException e) {
e.printStackTrace();
}
}方法二（Success）
public static void muxVideoAudio(String videoFilePath, String audioFilePath, String outputFile) {
try {
MediaExtractor videoExtractor = new MediaExtractor();
videoExtractor.setDataSource(videoFilePath);
MediaExtractor audioExtractor = new MediaExtractor();
audioExtractor.setDataSource(audioFilePath);
MediaMuxer muxer = new MediaMuxer(outputFile, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
videoExtractor.selectTrack(0);
MediaFormat videoFormat = videoExtractor.getTrackFormat(0);
int videoTrack = muxer.addTrack(videoFormat);
audioExtractor.selectTrack(0);
MediaFormat audioFormat = audioExtractor.getTrackFormat(0);
int audioTrack = muxer.addTrack(audioFormat);
LogUtil.d(TAG, "Video Format " + videoFormat.toString());
LogUtil.d(TAG, "Audio Format " + audioFormat.toString());
boolean sawEOS = false;
int frameCount = 0;
int offset = 100;
int sampleSize = 256 * 1024;
ByteBuffer videoBuf = ByteBuffer.allocate(sampleSize);
ByteBuffer audioBuf = ByteBuffer.allocate(sampleSize);
MediaCodec.BufferInfo videoBufferInfo = new MediaCodec.BufferInfo();
MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo();
videoExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
audioExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
muxer.start();
while (!sawEOS) {
videoBufferInfo.offset = offset;
videoBufferInfo.size = videoExtractor.readSampleData(videoBuf, offset);
if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0) {
sawEOS = true;
videoBufferInfo.size = 0;
} else {
videoBufferInfo.presentationTimeUs = videoExtractor.getSampleTime();
//noinspection WrongConstant
videoBufferInfo.flags = videoExtractor.getSampleFlags();
muxer.writeSampleData(videoTrack, videoBuf, videoBufferInfo);
videoExtractor.advance();
frameCount++;
}
}
boolean sawEOS2 = false;
int frameCount2 = 0;
while (!sawEOS2) {
frameCount2++;
audioBufferInfo.offset = offset;
audioBufferInfo.size = audioExtractor.readSampleData(audioBuf, offset);
if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0) {
sawEOS2 = true;
audioBufferInfo.size = 0;
} else {
audioBufferInfo.presentationTimeUs = audioExtractor.getSampleTime();
//noinspection WrongConstant
audioBufferInfo.flags = audioExtractor.getSampleFlags();
muxer.writeSampleData(audioTrack, audioBuf, audioBufferInfo);
audioExtractor.advance();
}
}
muxer.stop();
muxer.release();
LogUtil.d(TAG,"Output: "+outputFile);
} catch (IOException e) {
LogUtil.d(TAG, "Mixer Error 1 " + e.getMessage());
} catch (Exception e) {
LogUtil.d(TAG, "Mixer Error 2 " + e.getMessage());
}
}方法三
利用mp4parser实现
mp4parser是一个视频处理的开源工具箱，由于mp4parser里的方法都依靠工具箱里的一些内容，所以需要将这些内容打包成jar包，放到自己的工程里，才能对mp4parser的方法进行调用。
compile “com.googlecode.mp4parser:isoparser:1.1.21”
问题：上传Youtube压缩后，视频数据丢失严重，大部分就只剩下一秒钟的时长，相当于把视频变成图片了，囧
public boolean mux(String videoFile, String audioFile, final String outputFile) {
if (isStopMux) {
return false;
}
Movie video;
try {
video = MovieCreator.build(videoFile);
} catch (RuntimeException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
Movie audio;
try {
audio = MovieCreator.build(audioFile);
} catch (IOException e) {
e.printStackTrace();
return false;
} catch (NullPointerException e) {
e.printStackTrace();
return false;
}
Track audioTrack = audio.getTracks().get(0);
video.addTrack(audioTrack);
Container out = new DefaultMp4Builder().build(video);
FileOutputStream fos;
try {
fos = new FileOutputStream(outputFile);
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
}
BufferedWritableFileByteChannel byteBufferByteChannel = new
BufferedWritableFileByteChannel(fos);
try {
out.writeContainer(byteBufferByteChannel);
byteBufferByteChannel.close();
fos.close();
if (isStopMux) {
return false;
}
runOnUiThread(new Runnable() {
@Override
public void run() {
mCustomeProgressDialog.setProgress(100);
goShareActivity(outputFile);
// FileUtils.insertMediaDB(AddAudiosActivity.this,outputFile);//
}
});
} catch (IOException e) {
e.printStackTrace();
if (mCustomeProgressDialog.isShowing()) {
mCustomeProgressDialog.dismiss();
}
ToastUtil.showShort(getString(R.string.process_failed));
return false;
}
return true;
}
private static class BufferedWritableFileByteChannel implements WritableByteChannel {
private static final int BUFFER_CAPACITY = 2000000;
private boolean isOpen = true;
private final OutputStream outputStream;
private final ByteBuffer byteBuffer;
private final byte[] rawBuffer = new byte[BUFFER_CAPACITY];
private BufferedWritableFileByteChannel(OutputStream outputStream) {
this.outputStream = outputStream;
this.byteBuffer = ByteBuffer.wrap(rawBuffer);
}
@Override
public int write(ByteBuffer inputBuffer) throws IOException {
int inputBytes = inputBuffer.remaining();
if (inputBytes > byteBuffer.remaining()) {
dumpToFile();
byteBuffer.clear();
if (inputBytes > byteBuffer.remaining()) {
throw new BufferOverflowException();
}
}
byteBuffer.put(inputBuffer);
return inputBytes;
}
@Override
public boolean isOpen() {
return isOpen;
}
@Override
public void close() throws IOException {
dumpToFile();
isOpen = false;
}
private void dumpToFile() {
try {
outputStream.write(rawBuffer, 0, byteBuffer.position());
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}方法四
利用FFmpeg大法
FFmpeg 由于其丰富的 codec 插件，详细的文档说明，并且与其调试复杂量大的编解码代码(是的，用 MediaCodec 实现起来十分啰嗦和繁琐)还是不如调试一行 ffmpeg 命令来的简单。
Merge Video /Audio and retain both audios
可以实现，兼容性强，但由于是软解码，合并速度很慢，忍受不了，而相应的FFmpeg优化还不太了解，囧…….
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，如果有疑问大家可以留言交流，谢谢大家对创新互联的支持。
新闻标题：Android中音视频合成的几种方案详析
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