android 截取mp4,Android 使用 mp4parser 做视频裁剪

import android.text.TextUtils;

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;

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;

/**

* Author: AlanWang4523.

* Date: 17/3/21 11:40.

* Mail: alanwang6584@gmail.com

*/

public class VideoClipUtils {

private static final String TAG = VideoClipUtils.class.getSimpleName();

/**

* 裁剪视频

* @param srcPath 需要裁剪的原视频路径

* @param outPath 裁剪后的视频输出路径

* @param startTimeMs 裁剪的起始时间

* @param endTimeMs 裁剪的结束时间

*/

public static void clip(String srcPath, String outPath, double startTimeMs, double endTimeMs) throws IOException, IllegalArgumentException {

if (TextUtils.isEmpty(srcPath) || TextUtils.isEmpty(outPath)) {

throw new IllegalArgumentException("file path can't be null!!!!");

}

if (!(new File(srcPath).exists())) {

throw new IllegalArgumentException("the source file is not exist!!!!");

}

if (startTimeMs >= endTimeMs) {

throw new IllegalArgumentException("the startTimeMs is larger than endTimeMs!!!!");

}

Movie movie = MovieCreator.build(srcPath);

List tracks = movie.getTracks();

//移除旧的track

movie.setTracks(new LinkedList());

//处理的时间以秒为单位

double startTime = startTimeMs/1000;

double endTime = endTimeMs/1000;

Log.d(TAG, "--->>>>startTimeMs = " + startTimeMs + "\n endTimeMs = " + endTimeMs + "\n tracks.size = " + tracks.size());

//计算剪切时间，视频的采样间隔大，以视频为准

for (Track track : tracks) {

if (track.getSyncSamples() != null && track.getSyncSamples().length > 0) {

startTime = correctTimeToSyncSample(track, startTime, false);

endTime = correctTimeToSyncSample(track, endTime, true);

if (track.getHandler().equals("vide")) {

break;

}

}

}

Log.d(TAG, "--->>>>startTime = " + startTime + "\n endTime = " + endTime);

long currentSample;

double currentTime;

double lastTime;

long startSample1;

long endSample1;

long delta;

for (Track track : tracks) {

currentSample = 0;

currentTime = 0;

lastTime = -1;

startSample1 = -1;

endSample1 = -1;

//根据起始时间和截止时间获取起始sample和截止sample的位置

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

delta = track.getSampleDurations()[i];

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

startSample1 = currentSample;

}

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

endSample1 = currentSample;

}

lastTime = currentTime;

currentTime += (double)delta / (double)track.getTrackMetaData().getTimescale();

currentSample++;

}

Log.d(TAG, "track.getHandler() = " + track.getHandler() + "\n startSample1 = " + startSample1 + "\n endSample1 = " + endSample1);

if (startSample1 <= 0 && endSample1 <= 0) {

throw new RuntimeException("clip failed !!");

}

movie.addTrack(new CroppedTrack(track, startSample1, endSample1));// 添加截取的track

}

//合成视频mp4

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

FileOutputStream fos = new FileOutputStream(outPath);

FileChannel fco = fos.getChannel();

out.writeContainer(fco);

fco.close();

fos.close();

}

/**

* 换算剪切时间

* @param track

* @param cutHere

* @param next

* @return

*/

public 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];

int index = Arrays.binarySearch(track.getSyncSamples(), currentSample + 1);

if (index >= 0) {

timeOfSyncSamples[index] = 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];

}

}