MixVideoAndAudio /重复最后一帧

Question

我正在尝试使用Media Extractor和MediaMuxer混合视频和音频文件，但是当视频文件的时间少于音频文件的时间时，我遇到了一个问题。每当我尝试向前或向后移动控制器光标时，结果（mp4）文件的媒体控制器均无法正常工作，视频开始形成0。如果视频文件时间超过音频时间，则这不是问题文件。

我尝试过的是使用MediaMetadataRetriever / getFrameAtTime（long）从最后一帧创建视频，然后重复它，这解决了此问题，但是我不想通过最后一帧创建新视频的过程帧，我需要重复MediaExtractor的最后一帧以获得更清洁的解决方案。我不知道如何只重复MediaExtractor的最后一帧。

我使用的代码：

private void mixVideoAndAudio(String videoPath, String audioPath)  {
        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 type = videoFormat.getString(MediaFormat.KEY_MIME);
                if (type.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 type = audioFormat.getString(MediaFormat.KEY_MIME);
                if (type.startsWith("audio/")) {
                    audioTrackIndex = i;
                    break;
                }
            }

            videoExtractor.selectTrack(videoTrackIndex);
            audioExtractor.selectTrack(audioTrackIndex);

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

            String videoPathMuxer = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOWNLOADS) + "/v2.mp4";
            File file=new File(videoPathMuxer);
            try {
                file.getParentFile().mkdirs();
                file.createNewFile();
            } catch (IOException e) {
                e.printStackTrace();
            }

            MediaMuxer mediaMuxer = new MediaMuxer(videoPathMuxer, 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;
                videoBufferInfo.flags = 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;
                audioBufferInfo.flags = videoExtractor.getSampleFlags();
                mediaMuxer.writeSampleData(writeAudioTrackIndex, byteBuffer, audioBufferInfo);
                audioExtractor.advance();
            }



            if(videoBufferInfo.presentationTimeUs<audioBufferInfo.presentationTimeUs){

                //TODO repeat last Frame until video time >= audio time
            }





            mediaMuxer.stop();
            mediaMuxer.release();
            videoExtractor.release();
            audioExtractor.release();

            mVideoView.setVideoPath(videoPathMuxer);
            mVideoView.start();

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

任何建议将不胜感激。