Sự cố trong Cắt Nhiều clip từ Phim có thư viện mp4parser

Question

Tôi đang sử dụng thư viện mp4parser để cắt nhiều clip từ một video đã được quay lại. Nó hoạt động tốt Nếu tôi cắt một phần từ video. Nhưng khi tôi cố gắng cutt nhiều clip từ video clip 1 chỉ là cắt đúng. Khác chỉ là 0 hoặc 1 giây. Sau đây là Mã của tôi:

import android.app.ProgressDialog; 
import android.content.Context; 
import android.os.Handler; 
import android.os.Message; 
import android.util.Log; 
import android.widget.Toast; 

import com.coremedia.iso.IsoFile; 
import com.coremedia.iso.boxes.TimeToSampleBox; 
import com.googlecode.mp4parser.authoring.Movie; 
import com.googlecode.mp4parser.authoring.Track; 
import com.googlecode.mp4parser.authoring.builder.DefaultMp4Builder; 
import com.googlecode.mp4parser.authoring.container.mp4.MovieCreator; 
import com.googlecode.mp4parser.authoring.tracks.CroppedTrack; 

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.nio.channels.FileChannel; 
import java.text.SimpleDateFormat; 
import java.util.ArrayList; 
import java.util.Arrays; 
import java.util.Date; 
import java.util.LinkedList; 
import java.util.List; 
import java.util.concurrent.ExecutorService; 
import java.util.concurrent.Executors; 

import uk.org.humanfocus.hfi.Beans.TrimPoint; 
import uk.org.humanfocus.hfi.Utils.Constants; 
import uk.org.humanfocus.hfi.Utils.SimpleThreadFactory; 
import uk.org.humanfocus.hfi.Utils.Ut; 

/** 
* Shortens/Crops a track 
*/ 
public class ShortenExample { 

    private static final String TAG = "ShortenExample"; 
    private final Context mCxt; 
    private ExecutorService mThreadExecutor = null; 
    private SimpleInvalidationHandler mHandler; 
    private ProgressDialog mProgressDialog; 
    String filePath; 
    ArrayList<TrimPoint> mTrimPoints; 
    int videoLength; 
    ArrayList<String> trimVideos; 
    private class SimpleInvalidationHandler extends Handler { 

     @Override 
     public void handleMessage(final Message msg) { 
      switch (msg.what) { 
      case R.id.shorten: 
       mProgressDialog.dismiss(); 

       if (msg.arg1 == 0) 
        Toast.makeText(mCxt, 
          mCxt.getString(R.string.message_error) + " " + (String) msg.obj, 
          Toast.LENGTH_LONG).show(); 
       else 
        Toast.makeText(mCxt, 
          mCxt.getString(R.string.message_shortened) + " " + (String) msg.obj, 
          Toast.LENGTH_LONG).show(); 
       break; 
      } 
     } 
    } 

    public ShortenExample(Context context) { 
     mCxt = context; 
     mHandler = new SimpleInvalidationHandler(); 
     //mProgressDialog = new ProgressDialog(mCxt); 
     //mProgressDialog.setMessage("Wait Saving.."); 
     //mProgressDialog.setCancelable(false); 
    } 

    public void shorten(String filePath,ArrayList<TrimPoint> trimPoints, int endTime) { 
     trimVideos = new ArrayList<String>(); 
     this.filePath = filePath; 
     this.videoLength = endTime; 
     this.mTrimPoints = trimPoints; 
     Log.d(Constants.TAG,"End Time: "+endTime+" Trim Points: "+mTrimPoints.size()); 
     for (int i=0;i<trimPoints.size();i++){ 
      TrimPoint point = trimPoints.get(i); 
      int start=0; 
      int end = 0; 
      if(point.getTime()-5<0){ 
       start = 0; 
      }else{ 
       start = point.getTime()-5; 
      } 

      if(point.getTime()+5>videoLength){ 
       end = videoLength-1; 
      }else { 
       end = point.getTime() + 5; 
      } 
      Log.d(Constants.TAG,"Clip: "+start+" : "+end); 
      doShorten(start,end); 
     } 
     Log.d(Constants.TAG,"Done: "+trimVideos.size()); 
    } 

    private void doShorten(final int _startTime, final int _endTime) { 
     //mProgressDialog = Ut.ShowWaitDialog(mCxt, 0); 

     //mProgressDialog.show(); 


     if(mThreadExecutor == null) 
      mThreadExecutor = Executors.newSingleThreadExecutor(new SimpleThreadFactory("doShorten")); 

     //this.mThreadExecutor.execute(new Runnable() { 
     // public void run() { 
       try { 
        File folder = Ut.getTestMp4ParserVideosDir(mCxt); 
        //File folder = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DCIM),"HFVideos"+File.separator+"TEMP"); 
        //Log.d(Constants.TAG, folder.toString()); 
        if (!folder.exists()) { 
         Log.d(TAG, "failed to create directory"); 
        } 

        //Movie movie = new MovieCreator().build(new RandomAccessFile("/home/sannies/suckerpunch-distantplanet_h1080p/suckerpunch-distantplanet_h1080p.mov", "r").getChannel()); 
//     Movie movie = MovieCreator.build(new FileInputStream("/home/sannies/CSI.S13E02.HDTV.x264-LOL.mp4").getChannel()); 
        Movie movie = MovieCreator.build(new FileInputStream(new File(filePath)).getChannel()); 
        //Log.d(Constants.TAG,"Movie: "+movie.toString()); 
        List<Track> tracks = movie.getTracks(); 
        movie.setTracks(new LinkedList<Track>()); 
        // remove all tracks we will create new tracks from the old 

        double startTime = _startTime; 
        double endTime = _endTime;//(double) getDuration(tracks.get(0))/tracks.get(0).getTrackMetaData().getTimescale(); 

        boolean timeCorrected = false; 

        // Here we try to find a track that has sync samples. Since we can only start decoding 
        // at such a sample we SHOULD make sure that the start of the new fragment is exactly 
        // such a frame 
        for (Track track : tracks) { 
         if (track.getSyncSamples() != null && track.getSyncSamples().length > 0) { 
          if (timeCorrected) { 
           // This exception here could be a false positive in case we have multiple tracks 
           // with sync samples at exactly the same positions. E.g. a single movie containing 
           // multiple qualities of the same video (Microsoft Smooth Streaming file) 

           throw new RuntimeException("The startTime has already been corrected by another track with SyncSample. Not Supported."); 
          } 
          startTime = correctTimeToSyncSample(track, startTime, false); 
          endTime = correctTimeToSyncSample(track, endTime, true); 
          timeCorrected = true; 
         } 
        } 

        for (Track track : tracks) { 
         long currentSample = 0; 
         double currentTime = 0; 
         long startSample = -1; 
         long endSample = -1; 

         for (int i = 0; i < track.getDecodingTimeEntries().size(); i++) { 
          TimeToSampleBox.Entry entry = track.getDecodingTimeEntries().get(i); 
          for (int j = 0; j < entry.getCount(); j++) { 
           // entry.getDelta() is the amount of time the current sample covers. 

           if (currentTime <= startTime) { 
            // current sample is still before the new starttime 
            startSample = currentSample; 
           } 
           if (currentTime <= endTime) { 
            // current sample is after the new start time and still before the new endtime 
            endSample = currentSample; 
           } else { 
            // current sample is after the end of the cropped video 
            break; 
           } 
           currentTime += (double) entry.getDelta()/(double) track.getTrackMetaData().getTimescale(); 
           currentSample++; 
          } 
         } 
         movie.addTrack(new CroppedTrack(track, startSample, endSample)); 
        } 
        long start1 = System.currentTimeMillis(); 
        IsoFile out = new DefaultMp4Builder().build(movie); 
        long start2 = System.currentTimeMillis(); 

//     FileOutputStream fos = new FileOutputStream(String.format("output-%f-%f.mp4", startTime, endTime)); 
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date()); 
        String filename = folder.getPath() + File.separator + String.format("TMP4_APP_OUT-%f-%f", startTime, endTime) + "_" + timeStamp + ".mp4"; 
        trimVideos.add(filename); 
        FileOutputStream fos = new FileOutputStream(filename); 

        FileChannel fc = fos.getChannel(); 
        out.getBox(fc); 
        fc.close(); 
        fos.close(); 
        long start3 = System.currentTimeMillis(); 
        System.err.println("Building IsoFile took : " + (start2 - start1) + "ms"); 
        System.err.println("Writing IsoFile took : " + (start3 - start2) + "ms"); 
        System.err.println("Writing IsoFile speed : " + (new File(String.format("TMP4_APP_OUT-%f-%f", startTime, endTime)).length()/(start3 - start2)/1000) + "MB/s"); 

        Message.obtain(mHandler, R.id.shorten, 1, 0, filename).sendToTarget(); 
       } catch (FileNotFoundException e) { 
        Message.obtain(mHandler, R.id.shorten, 0, 0, e.getMessage()).sendToTarget(); 
        e.printStackTrace(); 
       } catch (IOException e) { 
        Message.obtain(mHandler, R.id.shorten, 0, 0, e.getMessage()).sendToTarget(); 
        e.printStackTrace(); 
       } 
       //mProgressDialog.dismiss(); 
     // } 
     //}); 

    } 

    protected static long getDuration(Track track) { 
     long duration = 0; 
     for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) { 
      duration += entry.getCount() * entry.getDelta(); 
     } 
     return duration; 
    } 

    private static double correctTimeToSyncSample(Track track, double cutHere, boolean next) { 
     double[] timeOfSyncSamples = new double[track.getSyncSamples().length]; 
     long currentSample = 0; 
     double currentTime = 0; 
     for (int i = 0; i < track.getDecodingTimeEntries().size(); i++) { 
      TimeToSampleBox.Entry entry = track.getDecodingTimeEntries().get(i); 
      for (int j = 0; j < entry.getCount(); j++) { 
       if (Arrays.binarySearch(track.getSyncSamples(), currentSample + 1) >= 0) { 
        // samples always start with 1 but we start with zero therefore +1 
        timeOfSyncSamples[Arrays.binarySearch(track.getSyncSamples(), currentSample + 1)] = currentTime; 
       } 
       currentTime += (double) entry.getDelta()/(double) track.getTrackMetaData().getTimescale(); 
       currentSample++; 
      } 
     } 
     double previous = 0; 
     for (double timeOfSyncSample : timeOfSyncSamples) { 
      if (timeOfSyncSample > cutHere) { 
       if (next) { 
        return timeOfSyncSample; 
       } else { 
        return previous; 
       } 
      } 
      previous = timeOfSyncSample; 
     } 
     return timeOfSyncSamples[timeOfSyncSamples.length - 1]; 
    } 


} 

Answer 1

Vấn đề chỉ là giả lập. Khi chúng tôi ghi lại video trong trình mô phỏng, nó ghi lại ít giây hơn thời gian thực tế. Mã làm việc trên thiết bị thực tế tốt.

Answer 2

BTW, trong khoảng thời gian tính bằng giây, bạn cần chia cho khoảng thời gian. Tôi thấy số lượng mục nhập (hoặc mẫu) thay đổi giữa các bản âm thanh và video có cùng thời lượng. Nhưng tôi là một tổng noob, đừng nghe tôi.

protected static double getDuration(Track track) { 
    double duration = 0; 
    for (TimeToSampleBox.Entry entry : track.getDecodingTimeEntries()) { 
     duration += entry.getCount() * entry.getDelta()/(double) track.getTrackMetaData().getTimescale(); 
    } 
    return duration; 
}