MediaCodec、AudioRecord 硬件编码录制视频
关于 MediaCodec 和 AudioRecord 的使用方法介绍，可以看其它博客：
MediaCodec 实现硬件解码，
使用 AudioRecord 录制 PCM、WAV 文件，AudioTrack 播放 PCM 文件
基本步骤为：
1) Camera、AudioRecord 获取原始图像、声音数据
2) MediaCodec 编码
3) MediaMuxer 合成 MP4 文件
获取原始图像、声音数据
获取图像数据使用 Camera 实现，首先打开 Camera：
mCamera = CameraHelper.openCamera();
if (mCamera == null) {
finish();
}
Camera.Parameters parameters = mCamera.getParameters();
mPreviewSize = CameraHelper.chooseCameraSize(parameters.getSupportedPreviewSizes(), width, height);
parameters.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
mPrevieweFormat = parameters.getPreviewFormat();
mCamera.setParameters(parameters);
mCamera.setDisplayOrientation(90);
mCamera.setPreviewCallback(this);
try {
mCamera.setPreviewDisplay(holder);
mCamera.startPreview();
} catch (IOException e) {
Log.e(TAG, "openCamera preview failed: " + e.getLocalizedMessage());
ToastHelper.show("相机预览开启失败！");
releaseCamera();
finish();
}onPreviewFrame 就是获取原始图像数据的地方：
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (mIsRecording) {
mRecorder.recordImage(data);
}
}AudioRecord 录制音频：
private class AudioRecordRunnable implements Runnable {
private AudioRecord mAudioRecord;
private int mBufferSize;
private AudioRecordRunnable() {
try {
mChannels = 1;
mBufferSize = AudioRecord.getMinBufferSize(mSampleRate, AudioFormat.CHANNEL_IN_MONO,
AudioFormat.ENCODING_PCM_16BIT);
mAudioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, mSampleRate,
AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT, mBufferSize);
} catch (Exception e) {
Log.e(TAG, "init AudioRecord exception: " + e.getLocalizedMessage());
}
if (mAudioRecord == null || mAudioRecord.getState() != AudioRecord.STATE_INITIALIZED) {
try {
mSampleRate = 16000;
mChannels = 2;
mBufferSize = AudioRecord.getMinBufferSize(mSampleRate, AudioFormat.CHANNEL_IN_STEREO,
AudioFormat.ENCODING_PCM_16BIT);
mAudioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, mSampleRate,
AudioFormat.CHANNEL_IN_STEREO, AudioFormat.ENCODING_PCM_16BIT, mBufferSize);
} catch (Exception e) {
Log.e(TAG, "init AudioRecord exception: " + e.getLocalizedMessage());
}
}
if (mAudioRecord == null || mAudioRecord.getState() != AudioRecord.STATE_INITIALIZED) {
Log.e(TAG, "cannot init AudioRecord");
}
}
@Override
public void run() {
android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
if (mAudioRecord == null || mAudioRecord.getState() != AudioRecord.STATE_INITIALIZED) {
return;
}
byte[] audioData = new byte[mBufferSize];
mAudioRecord.startRecording();
Log.d(TAG, "AudioRecord started");
int actualSize;
while (mIsRecording) {
actualSize = mAudioRecord.read(audioData, 0, audioData.length);
synchronized (mLockObject) {
if (actualSize > 0 && mIsRecording) {
mRecorder.recordSample(audioData);
}
}
}
if (mAudioRecord != null) {
mAudioRecord.stop();
mAudioRecord.release();
mAudioRecord = null;
Log.d(TAG, "AudioRecord released");
}
}
}音视频数据编码并合成为 MP4 文件
首先初始化音视频编码器和 MediaMuxer：
public static class Recorder {
private static final int DEFAULT_FRAME_RATE = 30;
private static final int DEFAULT_IFRAME_INTERVAL = 5;
private static final int DEFAULT_BITRATE_AUDIO = 128 * 1000;
private MediaMuxer mMuxer;
private MediaCodec mVideoEncoder;
private MediaCodec mAudioEncoder;
private MediaCodec.BufferInfo mVBufferInfo;
private MediaCodec.BufferInfo mABufferInfo;
private boolean mIsInitialized = false;
private long mVStartTime;
private long mAStartTime;
private int mVTrackIndex;
private int mATrackIndex;
private volatile boolean mMuxerStarted;
public void init(int width, int height, int colorFormat, int bitRate, int sampleRate,
int channels, String dstFilePath) throws Exception {
if (getCodecInfo(MIME_TYPE_AVC) == null || getCodecInfo(MIME_TYPE_AAC) == null) {
throw new Exception("cannot find suitable codec");
}
MediaFormat videoFormat = MediaFormat.createVideoFormat(MIME_TYPE_AVC, width, height);
videoFormat.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
videoFormat.setInteger(MediaFormat.KEY_FRAME_RATE, DEFAULT_FRAME_RATE);
videoFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, DEFAULT_IFRAME_INTERVAL);
videoFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, colorFormat);
mVideoEncoder = MediaCodec.createEncoderByType(MIME_TYPE_AVC);
mVideoEncoder.configure(videoFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mVideoEncoder.start();
MediaFormat audioFormat = MediaFormat.createAudioFormat(MIME_TYPE_AAC, sampleRate, channels);
audioFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
audioFormat.setInteger(MediaFormat.KEY_BIT_RATE, DEFAULT_BITRATE_AUDIO);
mAudioEncoder = MediaCodec.createEncoderByType(MIME_TYPE_AAC);
mAudioEncoder.configure(audioFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mAudioEncoder.start();
File file = new File(dstFilePath);
if (file.exists() && !file.delete()) {
Log.w(TAG, "delete file failed");
}
mMuxer = new MediaMuxer(dstFilePath, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
mMuxerStarted = false;
mVTrackIndex = -1;
mATrackIndex = -1;
mVStartTime = -1;
mAStartTime = -1;
mVBufferInfo = new MediaCodec.BufferInfo();
mABufferInfo = new MediaCodec.BufferInfo();
mIsInitialized = true;
Log.i(TAG, "Recorder initialized");
}
private static MediaCodecInfo getCodecInfo(final String mimeType) {
final int numCodecs = MediaCodecList.getCodecCount();
for (int i = 0; i < numCodecs; i++) {
final MediaCodecInfo codecInfo = MediaCodecList.getCodecInfoAt(i);
if (!codecInfo.isEncoder()) {
continue;
}
final String[] types = codecInfo.getSupportedTypes();
for (String type : types) {
if (type.equalsIgnoreCase(mimeType)) {
return codecInfo;
}
}
}
return null;
}
...
}接着接收音视频原始数据并编码，编码后合成至 MP4 文件，注意需要把音频轨道、视频轨道都添加到 MediaMuxer 之后才可以进行合成操作：
public void recordImage(byte[] image) throws Exception {
long pts;
if (mVStartTime == -1) {
mVStartTime = System.nanoTime();
pts = 0;
} else {
pts = (System.nanoTime() - mVStartTime) / 1000;
}
doRecord(mVideoEncoder, mVBufferInfo, image, pts);
}
public void recordSample(byte[] sample) throws Exception {
long pts;
if (mAStartTime == -1) {
mAStartTime = System.nanoTime();
pts = 0;
} else {
pts = (System.nanoTime() - mAStartTime) / 1000;
}
doRecord(mAudioEncoder, mABufferInfo, sample, pts);
}
private void doRecord(MediaCodec encoder, MediaCodec.BufferInfo bufferInfo, byte[] data,
long pts) throws Exception {
if (!mIsInitialized) {
Log.e(TAG, "Recorder must be initialized!");
return;
}
int index = encoder.dequeueInputBuffer(DEFAULT_TIMEOUT);
ByteBuffer[] inputBuffers = encoder.getInputBuffers();
ByteBuffer buffer = inputBuffers[index];
if (index >= 0) {
buffer.clear();
buffer.put(data);
encoder.queueInputBuffer(index, 0, data.length, pts, 0);
}
drainEncoder(encoder, bufferInfo);
}
private void drainEncoder(MediaCodec encoder, MediaCodec.BufferInfo bufferInfo) throws Exception {
int trackIndex = encoder == mVideoEncoder ? mVTrackIndex : mATrackIndex;
ByteBuffer[] outputBuffers = encoder.getOutputBuffers();
while (true) {
int index = encoder.dequeueOutputBuffer(bufferInfo, DEFAULT_TIMEOUT);
if (index == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
outputBuffers = encoder.getOutputBuffers();
} else if (index == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
trackIndex = addTrackIndex(encoder);
} else if (index == MediaCodec.INFO_TRY_AGAIN_LATER) {
break;
} else if (index < 0) {
Log.w(TAG, "drainEncoder unexpected result: " + index);
} else {
if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
continue;
}
if (bufferInfo.size != 0) {
ByteBuffer outputBuffer = outputBuffers[index];
if (outputBuffer == null) {
throw new RuntimeException("drainEncoder get outputBuffer " + index + " was null");
}
synchronized (this) {
if (!mMuxerStarted) {
wait();
}
}
outputBuffer.position(bufferInfo.offset);
outputBuffer.limit(bufferInfo.offset + bufferInfo.size);
mMuxer.writeSampleData(trackIndex, outputBuffer, bufferInfo);
}
encoder.releaseOutputBuffer(index, false);
}
}
}
private int addTrackIndex(MediaCodec encoder) {
int trackIndex;
synchronized (this) {
MediaFormat format = encoder.getOutputFormat();
if (getMediaType(format) == MEDIA_TYPE_VIDEO) {
mVTrackIndex = mMuxer.addTrack(format);
trackIndex = mVTrackIndex;
} else {
mATrackIndex = mMuxer.addTrack(format);
trackIndex = mATrackIndex;
}
if (mVTrackIndex != -1 && mATrackIndex != -1) {
mMuxer.start();
mMuxerStarted = true;
notifyAll();
Log.i(TAG, "MediaMuxer has added all track, notifyAll");
}
}
return trackIndex;
}录制结束后释放资源：
public void release() {
if (mVideoEncoder != null) {
mVideoEncoder.stop();
mVideoEncoder.release();
mVideoEncoder = null;
}
if (mAudioEncoder != null) {
mAudioEncoder.stop();
mAudioEncoder.release();
mAudioEncoder = null;
}
if (mMuxer != null) {
mMuxer.stop();
mMuxer.release();
mMuxer = null;
}
if (mIsInitialized) {
Log.i(TAG, "Recorder released");
}
mIsInitialized = false;
}源码已上传到 GitHub