在android中进行视频的分割

最近项目有个需求要对录制的视频进行分割，查了很多资料，看到ffmpeg可以对视频进行分割。上网找到别人基于android的开源ffmpeg，终于编译成功ffmpeg.so。但是要使用的话还要查ffmpeg的api，并且写jni的调用接口，非常麻烦。偶然情况下发现了开源软件mp4parser: http://code.google.com/p/mp4parser/ 一款非常棒的开源软件，可以对视频进行分割、组合等操作，而且使用起来非常简单。通过svn对其下载后可以看到里面带着视频分割的例子，但是是用java实现，将其稍微修改一下就可以用在Android上了。

首先将例子中的代码修改为一个工具类，通过接口传进视频文件的路径和截取视频的开始、结束时间。需要注意的是，如果传的开始时间是10s，视频一般不会刚好是从10s开始的，要根据视频的关键帧做一下调整。截取出来的视频会放到存储卡的Clip目录下。代码如下：

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package com.example.mp4clip;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.nio.channels.FileChannel;

import java.util.Arrays;

import java.util.LinkedList;

import java.util.List;

import android.os.Environment;

import android.util.Log;

import com.coremedia.iso.boxes.Container;

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;

public class ClipUtil {

private static final String TAG = "ClipUtil";

/**

* 截取指定时间段的视频

* @param path 视频的路径

* @param begin 需要截取的开始时间

* @param end 截取的结束时间

* @throws IOException

*/

public static void clipVideo(String path, double begin, double end)

throws IOException {

File mSdCardDir = Environment.getExternalStorageDirectory();

File f = new File(mSdCardDir.getAbsolutePath() + File.separator

+ Util.SAVE_PATH);

if (!f.exists()) {

f.mkdir();

}

// Movie movie = new MovieCreator().build(new

// RandomAccessFile("/home/sannies/suckerpunch-distantplanet_h1080p/suckerpunch-distantplanet_h1080p.mov",

// "r").getChannel());

Movie movie = MovieCreator.build(path);

List<Track> tracks = movie.getTracks();

movie.setTracks(new LinkedList<Track>());

// remove all tracks we will create new tracks from the old

double startTime1 = begin;

double endTime1 = end;

// double startTime2 = 30;

// double endTime2 = 40;

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)

Log.e(TAG,

"The startTime has already been corrected by another track with SyncSample. Not
Supported.");

throw new RuntimeException(

"The startTime has already been corrected by another track with SyncSample. Not
Supported.");

}

startTime1 = correctTimeToSyncSample(track, startTime1, false);

endTime1 = correctTimeToSyncSample(track, endTime1, true);

// startTime2 = correctTimeToSyncSample(track, startTime2,

// false);

// endTime2 = correctTimeToSyncSample(track, endTime2, true);

timeCorrected = true;

}

}

for (Track track : tracks) {

long currentSample = 0;

double currentTime = 0;

double lastTime = 0;

long startSample1 = -1;

long endSample1 = -1;

// long startSample2 = -1;

// long endSample2 = -1;

for (int i = 0; i < track.getSampleDurations().length; i++) {

long delta = track.getSampleDurations()[i];

if (currentTime > lastTime && currentTime <= startTime1) {

// current sample is still before the new starttime

startSample1 = currentSample;

}

if (currentTime > lastTime && currentTime <= endTime1) {

// current sample is after the new start time and still

// before the new endtime

endSample1 = currentSample;

}

// if (currentTime > lastTime && currentTime <= startTime2) {

// // current sample is still before the new starttime

// startSample2 = currentSample;

// }

// if (currentTime > lastTime && currentTime <= endTime2) {

// // current sample is after the new start time and still

// before the new endtime

// endSample2 = currentSample;

// }

lastTime = currentTime;

currentTime += (double) delta

/ (double) track.getTrackMetaData().getTimescale();

currentSample++;

}

movie.addTrack(new CroppedTrack(track, startSample1, endSample1));//
new

// AppendTrack(new

// CroppedTrack(track,

// startSample1,

// endSample1),

// new

// CroppedTrack(track,

// startSample2,

// endSample2)));

}

long start1 = System.currentTimeMillis();

Container out = new DefaultMp4Builder().build(movie);

long start2 = System.currentTimeMillis();

FileOutputStream fos = new FileOutputStream(f.getAbsolutePath()

+ File.separator

+ String.format("output-%f-%f.mp4", startTime1, endTime1));

FileChannel fc = fos.getChannel();

out.writeContainer(fc);

fc.close();

fos.close();

long start3 = System.currentTimeMillis();

Log.e(TAG, "Building
IsoFile took : " + (start2 - start1) + "ms");

Log.e(TAG, "Writing
IsoFile took : " + (start3 - start2) + "ms");

Log.e(TAG,

"Writing IsoFile speed : "

+ (new File(String.format("output-%f-%f.mp4",

startTime1, endTime1)).length()

/ (start3 - start2) / 1000) + "MB/s");

}

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.getSampleDurations().length; i++) {

long delta = track.getSampleDurations()[i];

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) delta

/ (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];

}

}

有了工具类，下面就是增加一个操作界面了。我用一个列表列出所有的视频，点击视频后就会在后台截取出5s~15s总共10s的视频。当然也可以根据需要加上自己想要的开始结束时间，代码如下：

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package com.example.mp4clip;

import java.io.IOException;

import java.lang.ref.SoftReference;

import android.app.Activity;

import android.content.Context;

import android.content.Intent;

import android.database.Cursor;

import android.graphics.drawable.Drawable;

import android.net.Uri;

import android.os.Bundle;

import android.os.Environment;

import android.provider.MediaStore;

import android.util.Log;

import android.util.SparseArray;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.AdapterView.OnItemClickListener;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.SimpleCursorAdapter;

import android.widget.TextView;

import edu.mit.mobile.android.imagecache.ImageCache;

import edu.mit.mobile.android.imagecache.ImageCache.OnImageLoadListener;

public class MainActivity extends Activity implements OnItemClickListener,

OnImageLoadListener {

private static final String TAG = "MainActivity";

ListView mList;

private Cursor mCursor;

private final SparseArray<SoftReference<ImageView>> mImageViewsToLoad = new SparseArray<SoftReference<ImageView>>();

private ImageCache mCache;

@Override

protected void onCreate(Bundle
savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

mCache = ImageCache.getInstance(this);

mCache.registerOnImageLoadListener(this);

mList = (ListView) findViewById(R.id.list);

mList.setOnItemClickListener(this);

mCursor = getContentResolver().query(

MediaStore.Video.Media.EXTERNAL_CONTENT_URI, null, null, null,

MediaStore.Video.Media.DATE_MODIFIED + "
desc");

SimpleCursorAdapter adapter = new videoListAdapter(this,

R.layout.video_listitem, mCursor,

new String[] { MediaStore.Video.Media.TITLE },

new int[] { R.id.video_title });

mList.setAdapter(adapter);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.main, menu);

return true;

}

public boolean onOptionsItemSelected(MenuItem item) {

// 扫描新多媒体文件,添加到数据库中

sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,

Uri.parse("file://"

+ Environment.getExternalStorageDirectory()

.getAbsolutePath())));

return false;

}

@Override

public void onItemClick(AdapterView<?> parent, View view, int position,

long id) {

if (mCursor.moveToPosition(position)) {

int index = -1;

index = mCursor.getColumnIndex(MediaStore.Video.Media.DATA);

String path = null;

if (index >= 0) {

path = mCursor.getString(index);

try {

ClipUtil.clipVideo(path, 5, 15);

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

}

private static final class ViewHolder {

/** 视频名称 */

TextView titleView;

/** 视频时长 */

TextView durationView;

/** 文件大小 */

TextView sizeView;

}

private class videoListAdapter extends SimpleCursorAdapter {

/*

* constructor.

*/

public videoListAdapter(Context context, int layout, Cursor c,

String[] from, int[] to) {

super(context, layout, c, from, to);

}

@Override

public int getCount() {

return super.getCount();

}

@Override

public Object getItem(int position) {

return super.getItem(position);

}

@Override

public long getItemId(int position) {

return super.getItemId(position);

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

View view = super.getView(position, convertView, parent);

Cursor cursor = getCursor();

cursor.moveToPosition(position);

ViewHolder holder = (ViewHolder) view.getTag();

if (holder == null) {

holder = new ViewHolder();

holder.titleView = (TextView) view

.findViewById(R.id.video_title);

holder.durationView = (TextView) view

.findViewById(R.id.video_duration);

holder.sizeView = (TextView) view.findViewById(R.id.video_size);

}

view.setTag(holder);

final ImageView iv = (ImageView) view.findViewById(R.id.thumbnail);

int index = -1;

index = mCursor.getColumnIndex(MediaStore.Video.Media.DATA);

String path = null;

if (index >= 0) {

path = mCursor.getString(index);

try {

Drawable draw = mCache.loadImage(position, Uri.parse(path),

120, 120);

if (draw != null) {

iv.setBackground(draw);

} else {

mImageViewsToLoad.put(position,

new SoftReference<ImageView>(iv));

}

} catch (IOException e) {

e.printStackTrace();

}

}

index = -1;

index = cursor.getColumnIndex(MediaStore.Video.Media.TITLE);

String title = null;

if (index >= 0) {

title = cursor.getString(index);

holder.titleView.setText(title);

}

index = -1;

index = cursor.getColumnIndex(MediaStore.Video.Media.DURATION);

int duration;

if (index >= 0) {

duration = cursor.getInt(index);

holder.durationView.setText(Util.durationFormat(duration));

}

index = -1;

index = cursor.getColumnIndex(MediaStore.Video.Media.SIZE);

long size;

if (index >= 0) {

size = cursor.getLong(index);

holder.sizeView.setText(Util.sizeFormat(size));

}

return view;

}

}

@Override

public void onImageLoaded(int id, Uri imageUri, Drawable image) {

Log.d(TAG, "onImageLoaded:" + id);

final SoftReference<ImageView> ivRef = mImageViewsToLoad.get(id);

if (ivRef == null) {

Log.d(TAG, "ivRef=null");

return;

}

final ImageView iv = ivRef.get();

if (iv == null) {

Log.d(TAG, "ivRef=null");

mImageViewsToLoad.remove(id);

return;

}

iv.setBackground(image);

}

}