So trimmen Sie Video mit MediaCodec

Question

Ich versuche, den Bildschirm mit MediaProjection API aufzuzeichnen. Ich möchte das Video schneiden, das von der Medienprojektion aufgenommen wurde. Gibt es eine Möglichkeit, dies zu tun, ohne eine Abhängigkeit von Dritten zu verwenden?

Answer 1

Nach vielen Graben, fand ich diesen Schnipsel

/** 
* @param srcPath the path of source video file. 
* @param dstPath the path of destination video file. 
* @param startMs starting time in milliseconds for trimming. Set to 
*     negative if starting from beginning. 
* @param endMs end time for trimming in milliseconds. Set to negative if 
*     no trimming at the end. 
* @param useAudio true if keep the audio track from the source. 
* @param useVideo true if keep the video track from the source. 
* @throws IOException 
*/ 
@TargetApi(Build.VERSION_CODES.LOLLIPOP) 
private static void genVideoUsingMuxer(String srcPath, String dstPath, 
             int startMs, int endMs, boolean useAudio, boolean 
                useVideo) 
     throws IOException { 
    // Set up MediaExtractor to read from the source. 
    MediaExtractor extractor = new MediaExtractor(); 
    extractor.setDataSource(srcPath); 
    int trackCount = extractor.getTrackCount(); 
    // Set up MediaMuxer for the destination. 
    MediaMuxer muxer; 
    muxer = new MediaMuxer(dstPath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); 
    // Set up the tracks and retrieve the max buffer size for selected 
    // tracks. 
    HashMap<Integer, Integer> indexMap = new HashMap<>(trackCount); 
    int bufferSize = -1; 
    for (int i = 0; i < trackCount; i++) { 
     MediaFormat format = extractor.getTrackFormat(i); 
     String mime = format.getString(MediaFormat.KEY_MIME); 
     boolean selectCurrentTrack = false; 
     if (mime.startsWith("audio/") && useAudio) { 
      selectCurrentTrack = true; 
     } else if (mime.startsWith("video/") && useVideo) { 
      selectCurrentTrack = true; 
     } 
     if (selectCurrentTrack) { 
      extractor.selectTrack(i); 
      int dstIndex = muxer.addTrack(format); 
      indexMap.put(i, dstIndex); 
      if (format.containsKey(MediaFormat.KEY_MAX_INPUT_SIZE)) { 
       int newSize = format.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE); 
       bufferSize = newSize > bufferSize ? newSize : bufferSize; 
      } 
     } 
    } 
    if (bufferSize < 0) { 
     bufferSize = DEFAULT_BUFFER_SIZE; 
    } 
    // Set up the orientation and starting time for extractor. 
    MediaMetadataRetriever retrieverSrc = new MediaMetadataRetriever(); 
    retrieverSrc.setDataSource(srcPath); 
    String degreesString = retrieverSrc.extractMetadata(
      MediaMetadataRetriever.METADATA_KEY_VIDEO_ROTATION); 
    if (degreesString != null) { 
     int degrees = Integer.parseInt(degreesString); 
     if (degrees >= 0) { 
      muxer.setOrientationHint(degrees); 
     } 
    } 
    if (startMs > 0) { 
     extractor.seekTo(startMs * 1000, MediaExtractor.SEEK_TO_CLOSEST_SYNC); 
    } 
    // Copy the samples from MediaExtractor to MediaMuxer. We will loop 
    // for copying each sample and stop when we get to the end of the source 
    // file or exceed the end time of the trimming. 
    int offset = 0; 
    int trackIndex = -1; 
    ByteBuffer dstBuf = ByteBuffer.allocate(bufferSize); 
    MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo(); 
    try { 
     muxer.start(); 
     while (true) { 
      bufferInfo.offset = offset; 
      bufferInfo.size = extractor.readSampleData(dstBuf, offset); 
      if (bufferInfo.size < 0) { 
       InstabugSDKLogger.d(TAG, "Saw input EOS."); 
       bufferInfo.size = 0; 
       break; 
      } else { 
       bufferInfo.presentationTimeUs = extractor.getSampleTime(); 
       if (endMs > 0 && bufferInfo.presentationTimeUs > (endMs * 1000)) { 
        InstabugSDKLogger.d(TAG, "The current sample is over the trim end time."); 
        break; 
       } else { 
        bufferInfo.flags = extractor.getSampleFlags(); 
        trackIndex = extractor.getSampleTrackIndex(); 
        muxer.writeSampleData(indexMap.get(trackIndex), dstBuf, 
          bufferInfo); 
        extractor.advance(); 
       } 
      } 
     } 
     muxer.stop(); 

     //deleting the old file 
     File file = new File(srcPath); 
     file.delete(); 
    } catch (IllegalStateException e) { 
     // Swallow the exception due to malformed source. 
     InstabugSDKLogger.w(TAG, "The source video file is malformed"); 
    } finally { 
     muxer.release(); 
    } 
    return; 
}