android - 停止 muxer 失败

Question

我遇到了媒体混合器的问题。为什么我的应用程序会崩溃？什么是解决方案？

java.lang.IllegalStateException: Failed to stop the muxer
    at android.media.MediaMuxer.nativeStop(Native Method)
    at android.media.MediaMuxer.stop(MediaMuxer.java:245)
    at com.app.filter.helper.config.VideoInfoUtils.combineVideo(VideoInfoUtils.java:159)
    at com.app.filter.helper.filter.video.VideoFilterView.handleSaveCompleted(VideoFilterView.java:74)
    at com.app.filter.helper.filter.video.VideoFilterView$ViewHandler.handleMessage(VideoFilterView.java:167)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)

我的java代码是

    public class VideoInfoUtils {

    public static MediaFormat getVideoInfo(String path) {

        MediaExtractor audioExtractor = new MediaExtractor();
        try {
            audioExtractor.setDataSource(path);
        } catch (IOException e) {
            e.printStackTrace();
        }
        int selectTrack = selectTrack(audioExtractor);
        if (selectTrack < 0) {
            throw new RuntimeException("No video track found in " + path);
        }
        MediaFormat format = audioExtractor.getTrackFormat(selectTrack);
        return format;

    }

    /**
     * Selects the video track, if any.
     *
     * @return the track index, or -1 if no video track is found.
     */
    private static int selectTrack(MediaExtractor mMediaExtractor) {
        // Select the first video track we find, ignore the rest.
        int numTracks = mMediaExtractor.getTrackCount();
        for (int i = 0; i < numTracks; i++) {
            MediaFormat format = mMediaExtractor.getTrackFormat(i);
            String mime = format.getString(MediaFormat.KEY_MIME);
            if (mime.startsWith("video/")) {
                return i;
            }
        }

        return -1;
    }


    @SuppressLint("NewApi")
    public static void combineVideo(String videoPath, String newVideo, String output) throws IllegalArgumentException {
        try {
            MediaExtractor videoExtractor = new MediaExtractor();
            videoExtractor.setDataSource(newVideo);
            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(videoPath);
            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;
            int writeVideoTrackIndex;
            int writeAudioTrackIndex;
            try {
                mediaMuxer = new MediaMuxer(output, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
                writeVideoTrackIndex = mediaMuxer.addTrack(videoFormat);
                writeAudioTrackIndex = mediaMuxer.addTrack(audioFormat);
                mediaMuxer.start();
            } catch (IOException ioe) {
                throw new RuntimeException("MediaMuxer creation failed", ioe);
            }

            ByteBuffer byteBuffer = ByteBuffer.allocate(500 * 1024);
            long videoStampTime = 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();
                videoStampTime = Math.abs(thirdTime - secondTime);
            }
            videoExtractor.unselectTrack(videoTrackIndex);
            videoExtractor.selectTrack(videoTrackIndex);

            long audioStampTime = 0;
            //获取帧之间的间隔时间
            {
                audioExtractor.readSampleData(byteBuffer, 0);
                if (audioExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) {
                    audioExtractor.advance();
                }
                audioExtractor.readSampleData(byteBuffer, 0);
                long secondTime = audioExtractor.getSampleTime();
                audioExtractor.advance();
                audioExtractor.readSampleData(byteBuffer, 0);
                long thirdTime = audioExtractor.getSampleTime();
                audioStampTime = Math.abs(thirdTime - secondTime);
                Log.e("time", audioStampTime + "");
            }

            audioExtractor.unselectTrack(audioTrackIndex);
            audioExtractor.selectTrack(audioTrackIndex);

            while (true) {
                int readVideoSampleSize = videoExtractor.readSampleData(byteBuffer, 0);
                if (readVideoSampleSize < 0) {
                    break;
                }
                videoBufferInfo.size = readVideoSampleSize;
                videoBufferInfo.presentationTimeUs += videoStampTime;
                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 += audioStampTime;
                audioBufferInfo.offset = 0;
                audioBufferInfo.flags = videoExtractor.getSampleFlags();
                mediaMuxer.writeSampleData(writeAudioTrackIndex, byteBuffer, audioBufferInfo);
                audioExtractor.advance();
            }

            if (mediaMuxer != null) {
                mediaMuxer.stop();
                mediaMuxer.release();
            }
            videoExtractor.release();
            audioExtractor.release();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

在我的应用程序中，我试图在视频上添加过滤器。但有时我的应用程序崩溃，有时它运行良好。错误是“无法停止 muxer”

Answer 1

我从 https://android.googlesource.com/platform/cts/+/jb-mr2-release/tests/tests/media/src/android/media/cts/MediaMuxerTest.java 得到以下代码

 // Throws exception b/c start() is not called.
        muxer = new MediaMuxer(outputFile, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
        muxer.addTrack(MediaFormat.createVideoFormat("video/avc", 480, 320));
        try {
            muxer.stop();
            fail("should throw IllegalStateException.");
        } catch (IllegalStateException e) {
            // expected
        }

据此，您需要确保在停止之前声明了互斥量。您可以像 isMutextStarted 一样保留变量来存储状态。但这只是 hack。

我建议你初始化它，只有 muxer 将在接下来启动。否则它会保持为 null，然后你的 mediaMuxer.stop() 和 release 部分不会被执行。