[源码]用MediaExtractor从视频中提取音频

http://pan.baidu.com/share/link?shareid=3772582450&uk=2268829156

界面比较简单，一个Textview和3个Button
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:orientation="vertical">
<TextView
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceMedium"
android:layout_width="wrap_content"
android:id="@+id/mainTextView1"/>
<LinearLayout
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:orientation="horizontal">
<Button
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="本地视频"
android:onClick="on1"/>
<Button
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="网络视频"
android:onClick="on3"/>
<Button
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:text="开始转换"
android:onClick="on2"/>
</LinearLayout>
</LinearLayout>

之后定义全局变量和创建MediaExtractor与MediaMuxer对象，这2个类负责从视频里提取音频
int type=0;
String path="";//视频路径
MediaExtractor mediaExtractor;
MediaMuxer mediaMuxer;
final String SDCARD_PATH = Environment.getExternalStorageDirectory().getPath();//SD卡根目录
TextView tx;

最后就是代码的核心了
private void muxerAudio(String file_in,String file_out) {
if(type==2)handler.obtainMessage(2,"网络连接中").sendToTarget();
mediaExtractor = new MediaExtractor();
MediaPlayer md=new MediaPlayer();//创建一个MediaPlayer用来获取视频时长
try
{
md.setDataSource(file_in.toString());
md.prepare();
}
catch (SecurityException e){}
catch (IllegalArgumentException e){}
catch (IllegalStateException e){}
catch (IOException e){}
int audioIndex = -1;//音频通道
int count=0;//已转换的时长
int size=md.getDuration();//获取视频时长
try {
mediaExtractor.setDataSource(file_in.toString());//设置视频路径，可以是网络链接
int trackCount = mediaExtractor.getTrackCount();//获取通道总数
for (int i = 0; i < trackCount; i++) {
MediaFormat trackFormat = mediaExtractor.getTrackFormat(i);
if (trackFormat.getString(MediaFormat.KEY_MIME).startsWith("audio/")) {
audioIndex = i;
}//获取音频通道
}
mediaExtractor.selectTrack(audioIndex);//切换到音频通道
MediaFormat trackFormat = mediaExtractor.getTrackFormat(audioIndex);
mediaMuxer = new MediaMuxer(file_out.toString(), MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
int writeAudioIndex = mediaMuxer.addTrack(trackFormat);
mediaMuxer.start();
ByteBuffer byteBuffer = ByteBuffer.allocate(trackFormat.getInteger(MediaFormat.KEY_MAX_INPUT_SIZE));
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
long stampTime = 0;
//获取相邻帧之间的间隔时间
{
mediaExtractor.readSampleData(byteBuffer, 0);
if (mediaExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) {
mediaExtractor.advance();
}
mediaExtractor.readSampleData(byteBuffer, 0);
long secondTime = mediaExtractor.getSampleTime();
mediaExtractor.advance();
mediaExtrac

代码的其他部分可以链接中的源码查看

顶顶

666

没法用

错误