主要的步骤分为视频录制，音频录制，视频合成。
视频录制采用
OpenGLES渲染预览摄像头画面，通过MediaCodec创建一个surface，然后通过创建一个新的egl环境共享预览的EglContext和这个surface绑定，渲染摄像头预览的fbo绑定的纹理，即可录制。
音频录制采用MediaCodec即可，从外部传入pcm数据进行编码录制。
音视频合成采用MediaMuxer合成。
录制
视频录制
OpenGLES渲染画面通过MediaCodec录制
音频录制
相关参考 MediaCodec硬编码pcm2aac
主要分为以下几步骤:
- 初始化
private void initAudioEncoder(String mineType, int sampleRate, int channel) {
try {
mAudioEncodec = MediaCodec.createEncoderByType(mineType);
MediaFormat audioFormat = MediaFormat.createAudioFormat(mineType, sampleRate, channel);
audioFormat.setInteger(MediaFormat.KEY_BIT_RATE, 96000);
audioFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
audioFormat.setInteger(MediaFormat.KEY_MAX_INPUT_SIZE, 4096);
mAudioEncodec.configure(audioFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mAudioBuffInfo = new MediaCodec.BufferInfo();
} catch (IOException e) {
e.printStackTrace();
mAudioEncodec = null;
mAudioBuffInfo = null;
}
}
- 开始录制
audioEncodec.start();
int outputBufferIndex = audioEncodec.dequeueOutputBuffer(audioBufferinfo, 0);
while (outputBufferIndex >= 0) {
ByteBuffer outputBuffer = audioEncodec.getOutputBuffers()[outputBufferIndex];
outputBuffer.position(audioBufferinfo.offset);
outputBuffer.limit(audioBufferinfo.offset + audioBufferinfo.size);
//设置时间戳
if (pts == 0) {
pts = audioBufferinfo.presentationTimeUs;
}
audioBufferinfo.presentationTimeUs = audioBufferinfo.presentationTimeUs - pts;
//写入数据
mediaMuxer.writeSampleData(audioTrackIndex, outputBuffer, audioBufferinfo);
audioEncodec.releaseOutputBuffer(outputBufferIndex, false);
outputBufferIndex = audioEncodec.dequeueOutputBuffer(audioBufferinfo, 0);
}
- 传入数据
这里编码为aac不用添加adts是因为这里是写入到mp4,而不是单独的aac文件
private long audioPts;
private long getAudioPts(int size, int sampleRate, int channel, int sampleBit) {
audioPts += (long) (1.0 * size / (sampleRate * channel * (sampleBit / 8)) * 1000000.0);
return audioPts;
}
public void putPcmData(byte[] buffer, int size) {
if (mAudioEncodecThread != null && !mAudioEncodecThread.isExit && buffer != null && size > 0) {
int inputBufferIndex = mAudioEncodec.dequeueInputBuffer(0);
if (inputBufferIndex >= 0) {
ByteBuffer byteBuffer = mAudioEncodec.getInputBuffers()[inputBufferIndex];
byteBuffer.clear();
byteBuffer.put(buffer);
//获取时间戳
long pts = getAudioPts(size, sampleRate, channel, sampleBit);
Log.e("zzz", "AudioTime = " + pts / 1000000.0f);
mAudioEncodec.queueInputBuffer(inputBufferIndex, 0, size, pts, 0);
}
}
}
- 停止录制
audioEncodec.stop();
audioEncodec.release();
audioEncodec = null;
音视频合成
有了音视频数据，通过MediaMuxer进行合并。
官方示例:
//MediaMuxer facilitates muxing elementary streams. Currently MediaMuxer supports MP4, Webm
//and 3GP file as the output. It also supports muxing B-frames in MP4 since Android Nougat.
//MediaMuxer muxer = new MediaMuxer("temp.mp4", OutputFormat.MUXER_OUTPUT_MPEG_4);
// More often, the MediaFormat will be retrieved from MediaCodec.getOutputFormat()
// or MediaExtractor.getTrackFormat().
MediaFormat audioFormat = new MediaFormat(...);
MediaFormat videoFormat = new MediaFormat(...);
int audioTrackIndex = muxer.addTrack(audioFormat);
int videoTrackIndex = muxer.addTrack(videoFormat);
ByteBuffer inputBuffer = ByteBuffer.allocate(bufferSize);
boolean finished = false;
BufferInfo bufferInfo = new BufferInfo();
muxer.start();
while(!finished) {
// getInputBuffer() will fill the inputBuffer with one frame of encoded
// sample from either MediaCodec or MediaExtractor, set isAudioSample to
// true when the sample is audio data, set up all the fields of bufferInfo,
// and return true if there are no more samples.
finished = getInputBuffer(inputBuffer, isAudioSample, bufferInfo);
if (!finished) {
int currentTrackIndex = isAudioSample ? audioTrackIndex : videoTrackIndex;
muxer.writeSampleData(currentTrackIndex, inputBuffer, bufferInfo);
}
};
muxer.stop();
muxer.release();
主要步骤如下:
- 初始化
mMediaMuxer = new MediaMuxer(savePath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
- 获取录制音视频的
TrackIndex
int outputBufferIndex = videoEncodec.dequeueOutputBuffer(videoBufferinfo, 0);
if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
videoTrackIndex = mediaMuxer.addTrack(videoEncodec.getOutputFormat());
}
int outputBufferIndex = audioEncodec.dequeueOutputBuffer(audioBufferinfo, 0);
if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
audioTrackIndex = mediaMuxer.addTrack(audioEncodec.getOutputFormat());
}
- 开始合成
mediaMuxer.start();
//写入视频数据
mediaMuxer.writeSampleData(videoTrackIndex, outputBuffer, videoBufferinfo);
//写入音频数据
mediaMuxer.writeSampleData(audioTrackIndex, outputBuffer, audioBufferinfo);
- 合成结束，写入头信息
mediaMuxer.stop();
mediaMuxer.release();
mediaMuxer = null;
具体查看demo：
https://github.com/ChinaZeng/SurfaceRecodeDemo