我有一些问题的音频和视频文件的音轨。 他们走了，每一件事都确定了我的code，但现在你可以使用它的合并音频文件和视频文件一起

I had some problem with tracks of audio and video files. they gone and every thing is ok with my code , but Now you can use it for merging an audio file and a video file together.

code：

private void muxing() {

String outputFile = "";

try {

    File file = new File(Environment.getExternalStorageDirectory() + File.separator + "final2.mp4");
    file.createNewFile();
    outputFile = file.getAbsolutePath();

    MediaExtractor videoExtractor = new MediaExtractor();
    AssetFileDescriptor afdd = getAssets().openFd("Produce.MP4");
    videoExtractor.setDataSource(afdd.getFileDescriptor() ,afdd.getStartOffset(),afdd.getLength());

    MediaExtractor audioExtractor = new MediaExtractor();
    audioExtractor.setDataSource(audioFilePath);

    Log.d(TAG, "Video Extractor Track Count " + videoExtractor.getTrackCount() );
    Log.d(TAG, "Audio Extractor Track Count " + audioExtractor.getTrackCount() );

    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);

    Log.d(TAG, "Video Format " + videoFormat.toString() );
    Log.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)
        {
            Log.d(TAG, "saw input EOS.");
            sawEOS = true;
            videoBufferInfo.size = 0;

        }
        else
        {
            videoBufferInfo.presentationTimeUs = videoExtractor.getSampleTime();
            videoBufferInfo.flags = videoExtractor.getSampleFlags();
            muxer.writeSampleData(videoTrack, videoBuf, videoBufferInfo);
            videoExtractor.advance();


            frameCount++;
            Log.d(TAG, "Frame (" + frameCount + ") Video PresentationTimeUs:" + videoBufferInfo.presentationTimeUs +" Flags:" + videoBufferInfo.flags +" Size(KB) " + videoBufferInfo.size / 1024);
            Log.d(TAG, "Frame (" + frameCount + ") Audio PresentationTimeUs:" + audioBufferInfo.presentationTimeUs +" Flags:" + audioBufferInfo.flags +" Size(KB) " + audioBufferInfo.size / 1024);

        }
    }

    Toast.makeText(getApplicationContext() , "frame:" + frameCount , Toast.LENGTH_SHORT).show();



    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)
        {
            Log.d(TAG, "saw input EOS.");
            sawEOS2 = true;
            audioBufferInfo.size = 0;
        }
        else
        {
            audioBufferInfo.presentationTimeUs = audioExtractor.getSampleTime();
            audioBufferInfo.flags = audioExtractor.getSampleFlags();
            muxer.writeSampleData(audioTrack, audioBuf, audioBufferInfo);
            audioExtractor.advance();


            Log.d(TAG, "Frame (" + frameCount + ") Video PresentationTimeUs:" + videoBufferInfo.presentationTimeUs +" Flags:" + videoBufferInfo.flags +" Size(KB) " + videoBufferInfo.size / 1024);
            Log.d(TAG, "Frame (" + frameCount + ") Audio PresentationTimeUs:" + audioBufferInfo.presentationTimeUs +" Flags:" + audioBufferInfo.flags +" Size(KB) " + audioBufferInfo.size / 1024);

        }
    }

    Toast.makeText(getApplicationContext() , "frame:" + frameCount2 , Toast.LENGTH_SHORT).show();

    muxer.stop();
    muxer.release();


} catch (IOException e) {
    Log.d(TAG, "Mixer Error 1 " + e.getMessage());
} catch (Exception e) {
    Log.d(TAG, "Mixer Error 2 " + e.getMessage());
}

}

由于这些样本codeS： MediaMuxer样品codeS -really完美

thanks to these sample codes:MediaMuxer Sample Codes-really perfect