Android(安卓)视频分离和合成(MediaMuxer和MediaExtractor)
16lz
2021-01-24
Android 视频的分离和合成这方面的资源网上是少之又少，学习的过程也是各种demo的看，各种demo的实验，各种坑的踩，为了让大家能够android的视频的分离和合成又个了解，写了下面的例子，完整例子再最下面。例子写的比较草，中间有较多的容错处理和代码的重构，也就懒得做了。另外导入的项目的时候，需要将工程input.mp4导入sd卡中，放在根目录里，由代码可以知道。
理论上来，我们可以利用的视频的分离和合成可以做很多事，比如裁剪视频大小，拼凑视频，对一段视频加入背景等。
MediaExtractor
MediaExtractor facilitates extraction of demuxed, typically encoded, media data from a data source.
其实就是将视频多信道的分离出来，比如声音和图像分隔出来，可以做到二次合成。
1.实例对象
2.setDateSource();//本地或者远程
3.获取想追踪的TrackIndex;
4.对TrackIndex的信道ByteBuffer数据进行处理
接下来讲一个mp4文件进行处理，分隔出audio信道和video信道
private void exactorMedia() { FileOutputStream videoOutputStream = null; FileOutputStream audioOutputStream = null; try { //分离的视频文件 File videoFile = new File(SDCARD_PATH, "output_video.mp4"); //分离的音频文件 File audioFile = new File(SDCARD_PATH, "output_audio"); videoOutputStream = new FileOutputStream(videoFile); audioOutputStream = new FileOutputStream(audioFile); //源文件 mediaExtractor.setDataSource(SDCARD_PATH + "/input.mp4"); //信道总数 int trackCount = mediaExtractor.getTrackCount(); int audioTrackIndex = -1; int videoTrackIndex = -1; for (int i = 0; i < trackCount; i++) { MediaFormat trackFormat = mediaExtractor.getTrackFormat(i); String mineType = trackFormat.getString(MediaFormat.KEY_MIME); //视频信道 if (mineType.startsWith("video/")) { videoTrackIndex = i; } //音频信道 if (mineType.startsWith("audio/")) { audioTrackIndex = i; } } ByteBuffer byteBuffer = ByteBuffer.allocate(500 * 1024); //切换到视频信道 mediaExtractor.selectTrack(videoTrackIndex); while (true) { int readSampleCount = mediaExtractor.readSampleData(byteBuffer, 0); if (readSampleCount < 0) { break; } //保存视频信道信息 byte[] buffer = new byte[readSampleCount]; byteBuffer.get(buffer); videoOutputStream.write(buffer); byteBuffer.clear(); mediaExtractor.advance(); } //切换到音频信道 mediaExtractor.selectTrack(audioTrackIndex); while (true) { int readSampleCount = mediaExtractor.readSampleData(byteBuffer, 0); if (readSampleCount < 0) { break; } //保存音频信息 byte[] buffer = new byte[readSampleCount]; byteBuffer.get(buffer); audioOutputStream.write(buffer); byteBuffer.clear(); mediaExtractor.advance(); } } catch (IOException e) { e.printStackTrace(); } finally { mediaExtractor.release(); try { videoOutputStream.close(); } catch (IOException e) { e.printStackTrace(); } }}但是我们注意分离出的两个文件大小其实是不相等的。
inputSize:243104audioSize:40720videoSize:199555MediaMuxer
上面是分离视频的，下面是合成视频。将所有的信道的信息合成一个视频
下面的例子基本涵盖所有的使用情况
MediaMuxer和MediaExtractor使用的例子
分离视频的纯视频
输入视频是input.mp4 ，分离保存的视频output_video;
private void muxerMedia() { mediaExtractor = new MediaExtractor(); int videoIndex = -1; try { mediaExtractor.setDataSource(SDCARD_PATH + "/input.mp4"); int trackCount = mediaExtractor.getTrackCount(); for (int i = 0; i < trackCount; i++) { MediaFormat trackFormat = mediaExtractor.getTrackFormat(i); String mimeType = trackFormat.getString(MediaFormat.KEY_MIME); // 取出视频的信号 if (mimeType.startsWith("video/")) { videoIndex = i; } } //切换道视频信号的信道 mediaExtractor.selectTrack(videoIndex); MediaFormat trackFormat = mediaExtractor.getTrackFormat(videoIndex); mediaMuxer = new MediaMuxer(SDCARD_PATH + "/output_video.mp4", MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); //追踪此信道 int trackIndex = mediaMuxer.addTrack(trackFormat); ByteBuffer byteBuffer = ByteBuffer.allocate(1024 * 500); MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo(); mediaMuxer.start(); long videoSampleTime; //获取每帧的之间的时间 { mediaExtractor.readSampleData(byteBuffer, 0); //skip first I frame if (mediaExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) mediaExtractor.advance(); mediaExtractor.readSampleData(byteBuffer, 0); long firstVideoPTS = mediaExtractor.getSampleTime(); mediaExtractor.advance(); mediaExtractor.readSampleData(byteBuffer, 0); long SecondVideoPTS = mediaExtractor.getSampleTime(); videoSampleTime = Math.abs(SecondVideoPTS - firstVideoPTS); Log.d("fuck", "videoSampleTime is " + videoSampleTime); } //重新切换此信道，不然上面跳过了3帧,造成前面的帧数模糊 mediaExtractor.unselectTrack(videoIndex); mediaExtractor.selectTrack(videoIndex); while (true) { //读取帧之间的数据 int readSampleSize = mediaExtractor.readSampleData(byteBuffer, 0); if (readSampleSize < 0) { break; } mediaExtractor.advance(); bufferInfo.size = readSampleSize; bufferInfo.offset = 0; bufferInfo.flags = mediaExtractor.getSampleFlags(); bufferInfo.presentationTimeUs += videoSampleTime; //写入帧的数据 mediaMuxer.writeSampleData(trackIndex, byteBuffer, bufferInfo); } //release mediaMuxer.stop(); mediaExtractor.release(); mediaMuxer.release(); Log.e("TAG", "finish"); } catch (IOException e) { e.printStackTrace(); }}这里比上面文件的要大，因为保存了一些信道信息等，而且是可以播放。
分离视频的纯音频
输入视频是input.mp4,输出的音频为output_audio;
private void muxerAudio() { mediaExtractor = new MediaExtractor(); int audioIndex = -1; try { mediaExtractor.setDataSource(SDCARD_PATH + "/input.mp4"); int trackCount = mediaExtractor.getTrackCount(); for (int i = 0; i < trackCount; i++) { MediaFormat trackFormat = mediaExtractor.getTrackFormat(i); if (trackFormat.getString(MediaFormat.KEY_MIME).startsWith("audio/")) { audioIndex = i; } } mediaExtractor.selectTrack(audioIndex); MediaFormat trackFormat = mediaExtractor.getTrackFormat(audioIndex); mediaMuxer = new MediaMuxer(SDCARD_PATH + "/output_audios", MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); int writeAudioIndex = mediaMuxer.addTrack(trackFormat); mediaMuxer.start(); ByteBuffer byteBuffer = ByteBuffer.allocate(500 * 1024); MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo(); long stampTime = 0; //获取帧之间的间隔时间 { mediaExtractor.readSampleData(byteBuffer, 0); if (mediaExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) { mediaExtractor.advance(); } mediaExtractor.readSampleData(byteBuffer, 0); long secondTime = mediaExtractor.getSampleTime(); mediaExtractor.advance(); mediaExtractor.readSampleData(byteBuffer, 0); long thirdTime = mediaExtractor.getSampleTime(); stampTime = Math.abs(thirdTime - secondTime); Log.e("fuck", stampTime + ""); } mediaExtractor.unselectTrack(audioIndex); mediaExtractor.selectTrack(audioIndex); while (true) { int readSampleSize = mediaExtractor.readSampleData(byteBuffer, 0); if (readSampleSize < 0) { break; } mediaExtractor.advance(); bufferInfo.size = readSampleSize; bufferInfo.flags = mediaExtractor.getSampleFlags(); bufferInfo.offset = 0; bufferInfo.presentationTimeUs += stampTime; mediaMuxer.writeSampleData(writeAudioIndex, byteBuffer, bufferInfo); } mediaMuxer.stop(); mediaMuxer.release(); mediaExtractor.release(); Log.e("fuck", "finish"); } catch (IOException e) { e.printStackTrace(); }}基本原理和上面差不多，只是我们这次选中音频的信道
合成视频
将上面分离出的output_video和分离出output_audio合成原来完整的视频
输入视频output_video，输入音频是output_audio,合成视频output
private void combineVideo() { try { MediaExtractor videoExtractor = new MediaExtractor(); videoExtractor.setDataSource(SDCARD_PATH + "/output_video"); MediaFormat videoFormat = null; int videoTrackIndex = -1; int videoTrackCount = videoExtractor.getTrackCount(); for (int i = 0; i < videoTrackCount; i++) { videoFormat = videoExtractor.getTrackFormat(i); String mimeType = videoFormat.getString(MediaFormat.KEY_MIME); if (mimeType.startsWith("video/")) { videoTrackIndex = i; break; } } MediaExtractor audioExtractor = new MediaExtractor(); audioExtractor.setDataSource(SDCARD_PATH + "/output_audio"); MediaFormat audioFormat = null; int audioTrackIndex = -1; int audioTrackCount = audioExtractor.getTrackCount(); for (int i = 0; i < audioTrackCount; i++) { audioFormat = audioExtractor.getTrackFormat(i); String mimeType = audioFormat.getString(MediaFormat.KEY_MIME); if (mimeType.startsWith("audio/")) { audioTrackIndex = i; break; } } videoExtractor.selectTrack(videoTrackIndex); audioExtractor.selectTrack(audioTrackIndex); MediaCodec.BufferInfo videoBufferInfo = new MediaCodec.BufferInfo(); MediaCodec.BufferInfo audioBufferInfo = new MediaCodec.BufferInfo(); MediaMuxer mediaMuxer = new MediaMuxer(SDCARD_PATH + "/output", MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4); int writeVideoTrackIndex = mediaMuxer.addTrack(videoFormat); int writeAudioTrackIndex = mediaMuxer.addTrack(audioFormat); mediaMuxer.start(); ByteBuffer byteBuffer = ByteBuffer.allocate(500 * 1024); long sampleTime = 0; { videoExtractor.readSampleData(byteBuffer, 0); if (videoExtractor.getSampleFlags() == MediaExtractor.SAMPLE_FLAG_SYNC) { videoExtractor.advance(); } videoExtractor.readSampleData(byteBuffer, 0); long secondTime = videoExtractor.getSampleTime(); videoExtractor.advance(); long thirdTime = videoExtractor.getSampleTime(); sampleTime = Math.abs(thirdTime - secondTime); } videoExtractor.unselectTrack(videoTrackIndex); videoExtractor.selectTrack(videoTrackIndex); while (true) { int readVideoSampleSize = videoExtractor.readSampleData(byteBuffer, 0); if (readVideoSampleSize < 0) { break; } videoBufferInfo.size = readVideoSampleSize; videoBufferInfo.presentationTimeUs += sampleTime; videoBufferInfo.offset = 0; videoBufferInfo.flags = videoExtractor.getSampleFlags(); mediaMuxer.writeSampleData(writeVideoTrackIndex, byteBuffer, videoBufferInfo); videoExtractor.advance(); } while (true) { int readAudioSampleSize = audioExtractor.readSampleData(byteBuffer, 0); if (readAudioSampleSize < 0) { break; } audioBufferInfo.size = readAudioSampleSize; audioBufferInfo.presentationTimeUs += sampleTime; audioBufferInfo.offset = 0; audioBufferInfo.flags = videoExtractor.getSampleFlags(); mediaMuxer.writeSampleData(writeAudioTrackIndex, byteBuffer, audioBufferInfo); audioExtractor.advance(); } mediaMuxer.stop(); mediaMuxer.release(); videoExtractor.release(); audioExtractor.release(); } catch (IOException e) { e.printStackTrace(); }}完整例子见MediaExtractor和MediaMuxer的Demo
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