重复播放声音，直到在MediaMuxer中完成视频

Question

我正在使用MediaMuxer在现有视频中添加声音。i已成功将音频添加到视频中。但是在该音频保持静音之后，音频只能播放。我想重复音频直到视频完成。以下是我将音频和音频混合的代码视频。我使用android MediaMuxer执行此任务。

@RequiresApi(api = Build.VERSION_CODES.JELLY_BEAN_MR2)
private void muxing(String srcVideo, String audio)
{
    String outputFile = "";

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

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

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

        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());
    }
}

请帮助我如何在视频中添加重复音频。开发人员网站中没有可用于执行此任务的文档。谢谢