安卓MediaMuxer音频问题

Question

我正在尝试使用MediaMuxer向视频中添加音轨。以下代码可以工作，但音频在视频中途停止。视频和音频文件都只有一首曲目。音频和视频的播放速度似乎都很好。音频文件比视频文件长，所以我不认为这是问题所在。我在这方面已经有一段时间了，现在想不通了。

private void createFinalVideo(){

    String outputFile = "";

     try {

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

        MediaExtractor videoExtractor = new MediaExtractor();
        videoExtractor.setDataSource(OUTPUT);

        MediaExtractor audioExtractor = new MediaExtractor();
        final AssetFileDescriptor afd = context.getAssets().openFd("audio.m4a");
        audioExtractor.setDataSource(afd.getFileDescriptor(),afd.getStartOffset(),afd.getLength());

        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);
        BufferInfo videoBufferInfo = new BufferInfo();
        BufferInfo audioBufferInfo = new BufferInfo();

        videoExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);
        audioExtractor.seekTo(0, MediaExtractor.SEEK_TO_CLOSEST_SYNC);

        muxer.start();

        while (!sawEOS) 
        {
            videoBufferInfo.offset = offset;
            audioBufferInfo.offset = offset;

            videoBufferInfo.size = videoExtractor.readSampleData(videoBuf, offset);
            audioBufferInfo.size = audioExtractor.readSampleData(audioBuf, offset);

            if (videoBufferInfo.size < 0 || audioBufferInfo.size < 0) 
            {
                Log.d(TAG, "saw input EOS.");
                sawEOS = true;
                videoBufferInfo.size = 0;
                audioBufferInfo.size = 0;
            } 
            else 
            {
                videoBufferInfo.presentationTimeUs = videoExtractor.getSampleTime();
                videoBufferInfo.flags = videoExtractor.getSampleFlags();
                muxer.writeSampleData(videoTrack, videoBuf, videoBufferInfo);
                videoExtractor.advance();

                audioBufferInfo.presentationTimeUs = audioExtractor.getSampleTime();
                audioBufferInfo.flags = audioExtractor.getSampleFlags();
                muxer.writeSampleData(audioTrack, audioBuf, audioBufferInfo);
                audioExtractor.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);

            }
        }
        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());
     }

    return;
}

打印出来的媒体格式如下

Video Format {max-input-size=1572864, frame-rate=28, height=1920, csd-0=java.nio.ByteArrayBuffer[position=0,limit=18,capacity=18], width=1072, durationUs=2968688, csd-1=java.nio.ByteArrayBuffer[position=0,limit=8,capacity=8], mime=video/avc, isDMCMMExtractor=1}

Audio Format {max-input-size=1572864, encoder-padding=708, aac-profile=2, csd-0=java.nio.ByteArrayBuffer[position=0,limit=2,capacity=2], sample-rate=44100, durationUs=19783401, channel-count=2, encoder-delay=2112, mime=audio/mp4a-latm, isDMCMMExtractor=1}

任何指导都将不胜感激。

谢谢

Answer 1

user346443:问题是视频提取器比音频提取器更快地提取数据。将音频和视频拆分为单独的循环修复了此问题。