一.前言
在 AAC 音频编码保存和解码播放和Camera 视频采集，H264 编码保存
两篇文章中介绍了如何通过 AudioRecord 和 MediaCodec 录制 AAC 音频以及如何通过 Camera
和 MediaCodec 录制 H264 视频。本文将介绍如何通过 MediaMuxer 合成 MP4 文件。
MP4
在 音视频开发基础概念中有介绍过，MP4 (或者称 MPEG-4) 是一种标准的数字多媒体容器格式，可以存储
音频数据和视频数据。对于视频格式，常见的是 H264 和 H265; 对于音频格式通常是 AAC 。
MediaMuxer
MediaMuxer 是 Android 用来产生一个混合音频和视频多媒体文件的 API ,只支持下面几种格式。
public static final inMUXER_OUTPUT_3GPP = 2;
public static final inMUXER_OUTPUT_HEIF = 3;
public static final inMUXER_OUTPUT_MPEG_4 = 0;
public static final inMUXER_OUTPUT_OGG = 4;
public static final inMUXER_OUTPUT_WEBM = 1;
1. 初始化
mMediaMuxer = new MediaMuxer(path, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
path 表示 MP4 文件的输出路径
2. 添加音频轨和视频轨
if (type == AAC_ENCODER) {
mAudioTrackIndex = mMediaMuxer.addTrack(mediaFormat);
}
if (type == H264_ENCODER) {
mVideoTrackIndex = mMediaMuxer.addTrack(mediaFormat);
}
传入 MediaFormat 对象从 MediaCodec 中获取。
3. 开始合成
mMediaMuxer.start();
4. 写入数据
mMediaMuxer.writeSampleData(avData.trackIndex, avData.byteBuffer, avData.bufferInfo);
5. 停止并释放资源
mMediaMuxer.stop();
mMediaMuxer.release();
二. 录制 MP4
AudioTrack、Camera、MediaCodec 和 MediaMuxer 录制 MP4 流程如下图所示：
image.png
1. 音频录制
音频录制使用 AudioRecord
public class AudioRecorder {
private int mAudioSource;
private int mSampleRateInHz;
private int mChannelConfig;
private int mAudioFormat;
private int mBufferSizeInBytes;
private AudioRecord mAudioRecord;
private volatile boolean mIsRecording;
private Callback mCallback;
private byte[] mBuffer;
public void setCallback(Callback callback) {
mCallback = callback;
}
public interface Callback {
void onAudioOutput(byte[] data);
}
public AudioRecorder(int audioSource, int sampleRateInHz, int channelConfig, int audioFormat, int bufferSizeInBytes) {
mAudioSource = audioSource;
mSampleRateInHz = sampleRateInHz;
mChannelConfig = channelConfig;
mAudioFormat = audioFormat;
mBufferSizeInBytes = bufferSizeInBytes;
mAudioRecord = new AudioRecord(audioSource, sampleRateInHz, channelConfig, audioFormat, bufferSizeInBytes);
mIsRecording = false;
int minBufferSize = AudioRecord.getMinBufferSize(sampleRateInHz, channelConfig, AudioFormat.ENCODING_PCM_16BIT);
mBuffer = new byte[Math.min(2048, minBufferSize)];
}
public void start() {
if (mIsRecording) {
return;
}
new Thread(new Runnable() {
@Override
public void run() {
onStart();
}
}).start();
}
public void onStart() {
if (mAudioRecord == null) {
mAudioRecord = new android.media.AudioRecord(mAudioSource, mSampleRateInHz, mChannelConfig, mAudioFormat, mBufferSizeInBytes);
}
mAudioRecord.startRecording();
mIsRecording = true;
while (mIsRecording) {
int len = mAudioRecord.read(mBuffer, 0, mBuffer.length);
if (len > 0) {
if (mCallback != null) {
mCallback.onAudioOutput(mBuffer);
}
}
}
mAudioRecord.stop();
mAudioRecord.release();
mAudioRecord = null;
}
public void stop() {
mIsRecording = false;
}
}
2. 音频编码
音频编码使用阻塞队列 BlockingQueue 来缓冲数据，编码成 AAC 格式。
public class AacEncoder {
public static final int AAC_ENCODER = 2;
private MediaCodec mAudioEncoder;
private MediaFormat mMediaFormat;
private BlockingQueue<byte[]> mDataQueue;
private volatile boolean mIsEncoding;
private Callback mCallback;
private static final String AUDIO_MIME_TYPE = "audio/mp4a-latm";//就是 aac
public void setCallback(Callback callback) {
mCallback = callback;
}
public interface Callback {
void outputMediaFormat(int type, MediaFormat mediaFormat);
void onEncodeOutput(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo);
void onStop(int type);
}
public AacEncoder(int sampleRateInHz, int channelConfig, int bufferSizeInBytes) {
try {
mAudioEncoder = MediaCodec.createEncoderByType(AUDIO_MIME_TYPE);
mMediaFormat = MediaFormat.createAudioFormat(AUDIO_MIME_TYPE, sampleRateInHz, channelConfig == AudioFormat.CHANNEL_OUT_MONO ? 1 : 2);
mMediaFormat.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
mMediaFormat.setInteger(MediaFormat.KEY_CHANNEL_MASK, AudioFormat.CHANNEL_IN_STEREO);//CHANNEL_IN_STEREO 立体声
int bitRate = sampleRateInHz * 16 * channelConfig == AudioFormat.CHANNEL_IN_MONO ? 1 : 2;
mMediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, bitRate);
mMediaFormat.setInteger(MediaFormat.KEY_CHANNEL_COUNT, channelConfig == AudioFormat.CHANNEL_IN_MONO ? 1 : 2);
mMediaFormat.setInteger(MediaFormat.KEY_SAMPLE_RATE, sampleRateInHz);
mAudioEncoder.configure(mMediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
} catch (IOException e) {
}
mDataQueue = new ArrayBlockingQueue<>(10);
mIsEncoding = false;
}
public void start() {
if (mIsEncoding) {
return;
}
new Thread(new Runnable() {
@Override
public void run() {
onStart();
}
}).start();
}
public void stop() {
mIsEncoding = false;
}
private void onStart() {
mIsEncoding = true;
mAudioEncoder.start();
byte[] pcmData;
int inputIndex;
ByteBuffer inputBuffer;
ByteBuffer[] inputBuffers = mAudioEncoder.getInputBuffers();
int outputIndex;
ByteBuffer outputBuffer;
ByteBuffer[] outputBuffers = mAudioEncoder.getOutputBuffers();
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
while (mIsEncoding || !mDataQueue.isEmpty()) {
pcmData = dequeueData();
if (pcmData == null) {
continue;
}
long pts = System.currentTimeMillis() * 1000 - AVTimer.getBaseTimestampUs();
inputIndex = mAudioEncoder.dequeueInputBuffer(10_000);
if (inputIndex >= 0) {
inputBuffer = inputBuffers[inputIndex];
inputBuffer.clear();
inputBuffer.limit(pcmData.length);
inputBuffer.put(pcmData);
mAudioEncoder.queueInputBuffer(inputIndex, 0, pcmData.length, pts, 0);
}
outputIndex = mAudioEncoder.dequeueOutputBuffer(bufferInfo, 10_000);
if (outputIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
outputBuffers = mAudioEncoder.getOutputBuffers();
} else if (outputIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
MediaFormat newFormat = mAudioEncoder.getOutputFormat();
if (null != mCallback) {
mCallback.outputMediaFormat(AAC_ENCODER, newFormat);
}
}
while (outputIndex >= 0) {
outputBuffer = outputBuffers[outputIndex];
if (mCallback != null) {
mCallback.onEncodeOutput(outputBuffer, bufferInfo);
}
mAudioEncoder.releaseOutputBuffer(outputIndex, false);
outputIndex = mAudioEncoder.dequeueOutputBuffer(bufferInfo, 10_000);
}
}
mAudioEncoder.stop();
mAudioEncoder.release();
mAudioEncoder = null;
if (mCallback != null) {
mCallback.onStop(AAC_ENCODER);
}
}
private byte[] dequeueData() {
if (mDataQueue.isEmpty()) {
return null;
}
try {
return mDataQueue.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
public void queueData(byte[] data) {
if (!mIsEncoding) {
return;
}
try {
mDataQueue.put(data);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
3. 视频录制
视频录制通过摄像头 Camera 采集，由于 Camera 采集的视频默认是横屏的，还需要通过 YUVEngine 进行转换
public class H264VideoRecord implements CameraHelper.PreviewCallback, H264Encoder.Callback {
private CameraHelper mCameraHelper;
private H264Encoder mH264Encoder;
private Callback mCallback;
public void setCallback(Callback callback) {
mCallback = callback;
}
public interface Callback {
void outputMediaFormat(int type, MediaFormat mediaFormat);
void outputVideo(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo);
void onStop(int type);
}
public H264VideoRecord(Activity activity, SurfaceView surfaceView) {
mCameraHelper = new CameraHelper(surfaceView, activity);
mCameraHelper.setPreviewCallback(this);
}
public void start() {
mH264Encoder.start();
}
public void stop() {
mH264Encoder.stop();
mCameraHelper.stop();
}
@Override
public void onFrame(byte[] data) {
mH264Encoder.queueData(data);
}
@Override
public void outputMediaFormat(int type, MediaFormat mediaFormat) {
if (mCallback == null) {
return;
}
mCallback.outputMediaFormat(type, mediaFormat);
}
@Override
public void onEncodeOutput(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
if (mCallback == null) {
return;
}
mCallback.outputVideo(byteBuffer, bufferInfo);
}
@Override
public void onStop(int type) {
if (mCallback == null) {
return;
}
mCallback.onStop(type);
}
@Override
public void onOperate(int width, int height, int fps) {
mH264Encoder = new H264Encoder(width, height, fps);
mH264Encoder.setCallback(this);
}
}
public class CameraHelper {
private int mPreWidth;
private int mPreHeight;
private int mFrameRate;
private Camera mCamera;
private Camera.Size mPreviewSize;
private Camera.Parameters mCameraParameters;
private boolean mIsPreviewing = false;
private Activity mContext;
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
private CameraPreviewCallback mCameraPreviewCallback;
private PreviewCallback mPreviewCallback;
public void setPreviewCallback(PreviewCallback previewCallback) {
mPreviewCallback = previewCallback;
}
public interface PreviewCallback {
void onFrame(byte[] data);
void onOperate(int width, int height, int fps);
}
public CameraHelper(SurfaceView surfaceView, Activity context) {
mSurfaceView = surfaceView;
mContext = context;
mSurfaceView.setKeepScreenOn(true);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
mSurfaceHolder.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
doOpenCamera();
doStartPreview(mContext, surfaceHolder);
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
if (mCamera == null) {
return;
}
mCamera.stopPreview();
mCamera.release();
mCamera = null;
}
});
}
private void doOpenCamera() {
if (mCamera != null) {
return;
}
mCamera = Camera.open();
}
private void doStartPreview(Activity activity, SurfaceHolder surfaceHolder) {
if (mIsPreviewing) {
return;
}
mContext = activity;
setCameraDisplayOrientation(activity, Camera.CameraInfo.CAMERA_FACING_BACK);
setCameraParameters(surfaceHolder);
try {
mCamera.setPreviewDisplay(surfaceHolder);
} catch (IOException e) {
e.printStackTrace();
}
mCamera.startPreview();
mIsPreviewing = true;
mPreviewCallback.onOperate(mPreWidth, mPreHeight, mFrameRate);
}
public void stop() {
if (mCamera != null) {
mCamera.setPreviewCallbackWithBuffer(null);
if (mIsPreviewing) {
mCamera.stopPreview();
}
mIsPreviewing = false;
mCamera.release();
mCamera = null;
}
}
private void setCameraDisplayOrientation(Activity activity, int cameraId) {
Camera.CameraInfo info = new Camera.CameraInfo();
Camera.getCameraInfo(cameraId, info);
int rotation = activity.getWindowManager().getDefaultDisplay().getRotation();
int degrees = 0;
switch (rotation) {
case Surface.ROTATION_0:
degrees = 0;
break;
case Surface.ROTATION_90:
degrees = 90;
break;
case Surface.ROTATION_180:
degrees = 180;
break;
case Surface.ROTATION_270:
degrees = 270;
break;
}
int result = 0;
if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
result = (info.orientation + degrees) % 360;
result = (360 - result) % 360;
} else {
result = (info.orientation - degrees + 360) % 360;
}
mCamera.setDisplayOrientation(result);
}
private void setCameraParameters(SurfaceHolder surfaceHolder) {
if (!mIsPreviewing && mCamera != null) {
mCameraParameters = mCamera.getParameters();
mCameraParameters.setPreviewFormat(ImageFormat.NV21);
List<Camera.Size> supportedPreviewSizes = mCameraParameters.getSupportedPreviewSizes();
Collections.sort(supportedPreviewSizes, new Comparator<Camera.Size>() {
@Override
public int compare(Camera.Size o1, Camera.Size o2) {
Integer left = o1.width;
Integer right = o2.width;
return left.compareTo(right);
}
});
DisplayMetrics displayMetrics = mContext.getResources().getDisplayMetrics();
for (Camera.Size size : supportedPreviewSizes) {
if (size.width >= displayMetrics.heightPixels && size.height >= displayMetrics.widthPixels) {
if ((1.0f * size.width / size.height) == (1.0f * displayMetrics.heightPixels / displayMetrics.widthPixels)) {
mPreviewSize = size;
break;
}
}
}
if (mPreviewSize != null) {
mPreWidth = mPreviewSize.width;
mPreHeight = mPreviewSize.height;
} else {
mPreWidth = 1280;
mPreHeight = 720;
}
mCameraParameters.setPreviewSize(mPreWidth, mPreHeight);
//set fps range.
int defminFps = 0;
int defmaxFps = 0;
List<int[]> supportedPreviewFpsRange = mCameraParameters.getSupportedPreviewFpsRange();
for (int[] fps : supportedPreviewFpsRange) {
if (defminFps <= fps[PREVIEW_FPS_MIN_INDEX] && defmaxFps <= fps[PREVIEW_FPS_MAX_INDEX]) {
defminFps = fps[PREVIEW_FPS_MIN_INDEX];
defmaxFps = fps[PREVIEW_FPS_MAX_INDEX];
}
}
//设置相机预览帧率
mCameraParameters.setPreviewFpsRange(defminFps, defmaxFps);
mFrameRate = defmaxFps / 1000;
surfaceHolder.setFixedSize(mPreWidth, mPreHeight);
mCameraPreviewCallback = new CameraPreviewCallback();
mCamera.addCallbackBuffer(new byte[mPreHeight * mPreWidth * 3 / 2]);
mCamera.setPreviewCallbackWithBuffer(mCameraPreviewCallback);
List<String> focusModes = mCameraParameters.getSupportedFocusModes();
for (String focusMode : focusModes) {//检查支持的对焦
if (focusMode.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
mCameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
} else if (focusMode.contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE)) {
mCameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
} else if (focusMode.contains(Camera.Parameters.FOCUS_MODE_AUTO)) {
mCameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
}
}
mCamera.setParameters(mCameraParameters);
}
}
class CameraPreviewCallback implements Camera.PreviewCallback {
private CameraPreviewCallback() {
}
@Override
public void onPreviewFrame(byte[] data, Camera camera) {
if (!mIsPreviewing || mCamera == null) {
return;
}
Camera.Size size = camera.getParameters().getPreviewSize();
//通过回调,拿到的data数据是原始数据
//丢给VideoRunnable线程,使用MediaCodec进行h264编码操作
if (data != null) {
if (mPreviewCallback != null) {
mPreviewCallback.onFrame(data);
}
camera.addCallbackBuffer(data);
} else {
camera.addCallbackBuffer(new byte[size.width * size.height * 3 / 2]);
}
}
}
}
4. 视频编码
视频编码使用阻塞队列 BlockingQueue 来缓冲数据，编码成 H264 格式。
public class H264Encoder {
public static final String VIDEO_MIME_TYPE = "video/avc";//就是 H264
public static final int H264_ENCODER = 1;
private MediaCodec mMediaCodec;
private MediaFormat mMediaFormat;
private BlockingQueue<byte[]> mQueue;
private MediaCodecInfo mMediaCodecInfo;
private int mColorFormat;
private int mWidth;
private int mHeight;
private int mBitRate;
private byte[] mYUVBuffer;
private byte[] mRotatedYUVBuffer;
private int[] mOutWidth;
private int[] mOutHeight;
private ExecutorService mExecutorService;
private volatile boolean mIsEncoding;
private Callback mCallback;
public void setCallback(Callback callback) {
mCallback = callback;
}
public interface Callback {
void outputMediaFormat(int type, MediaFormat mediaFormat);
void onEncodeOutput(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo);
void onStop(int type);
}
public H264Encoder(int width, int height, int fps) {
Log.e("eee", "w:" + width + "h:" + height + "fps:" + fps);
mWidth = width;
mHeight = height;
mQueue = new LinkedBlockingQueue<>();
mMediaCodecInfo = selectCodecInfo();
mColorFormat = selectColorFormat(mMediaCodecInfo);
mBitRate = (mWidth * mHeight * 3 / 2) * 8 * fps;
mMediaFormat = MediaFormat.createVideoFormat(VIDEO_MIME_TYPE, mHeight, mWidth);
mMediaFormat.setInteger(MediaFormat.KEY_BIT_RATE, mBitRate);// todo 没有这一行会报错 configureCodec returning error -38
mMediaFormat.setInteger(MediaFormat.KEY_FRAME_RATE, fps);
mMediaFormat.setInteger(MediaFormat.KEY_COLOR_FORMAT, mColorFormat);
mMediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
try {
mMediaCodec = MediaCodec.createByCodecName(mMediaCodecInfo.getName());
} catch (IOException e) {
e.printStackTrace();
}
mMediaCodec.configure(mMediaFormat, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
mExecutorService = Executors.newFixedThreadPool(1);
mYUVBuffer = new byte[YUVUtil.getYUVBuffer(width, height)];
mRotatedYUVBuffer = new byte[YUVUtil.getYUVBuffer(width, height)];
mOutWidth = new int[1];
mOutHeight = new int[1];
YUVEngine.startYUVEngine();
}
public void start() {
if (mIsEncoding) {
return;
}
mExecutorService.execute(new Runnable() {
@Override
public void run() {
mIsEncoding = true;
mMediaCodec.start();
while (mIsEncoding) {
byte[] data = dequeueData();
if (data == null) {
continue;
}
encodeVideoData(data);
}
mMediaCodec.stop();
mMediaCodec.release();
if (mCallback != null) {
mCallback.onStop(H264_ENCODER);
}
}
});
}
public void stop() {
mIsEncoding = false;
}
private byte[] dequeueData() {
if (mQueue.isEmpty()) {
return null;
}
try {
return mQueue.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
public void queueData(byte[] data) {
if (data == null || !mIsEncoding) {
return;
}
try {
mQueue.put(data);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
private void encodeVideoData(byte[] data) {
MediaCodec.BufferInfo bufferInfo = new MediaCodec.BufferInfo();
mRotatedYUVBuffer = transferFrameData(data, mYUVBuffer, mRotatedYUVBuffer);
ByteBuffer[] inputBuffers = mMediaCodec.getInputBuffers();
int inputIndex = mMediaCodec.dequeueInputBuffer(10_000);
if (inputIndex >= 0) {
ByteBuffer byteBuffer = inputBuffers[inputIndex];
byteBuffer.clear();
byteBuffer.put(mRotatedYUVBuffer);
long pts = System.currentTimeMillis() * 1000 - AVTimer.getBaseTimestampUs();
mMediaCodec.queueInputBuffer(inputIndex, 0, mRotatedYUVBuffer.length, pts, 0);
}
ByteBuffer[] outputBuffers = mMediaCodec.getOutputBuffers();
int outputIndex = mMediaCodec.dequeueOutputBuffer(bufferInfo, 10_000);
if (outputIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
outputBuffers = mMediaCodec.getOutputBuffers();
} else if (outputIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
MediaFormat newFormat = mMediaCodec.getOutputFormat();
if (null != mCallback) {
mCallback.outputMediaFormat(H264_ENCODER, newFormat);
}
}
while (outputIndex >= 0) {
ByteBuffer byteBuffer = outputBuffers[outputIndex];
if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_CODEC_CONFIG) != 0) {
bufferInfo.size = 0;
}
if (bufferInfo.size != 0 && mCallback != null) {
// boolean keyFrame = (bufferInfo.flags & MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0;
// Log.i(TAG, "is key frame :%s"+keyFrame);
mCallback.onEncodeOutput(byteBuffer, bufferInfo);
}
mMediaCodec.releaseOutputBuffer(outputIndex, false);
outputIndex = mMediaCodec.dequeueOutputBuffer(bufferInfo, 10_000);
}
}
private byte[] transferFrameData(byte[] data, byte[] yuvBuffer, byte[] rotatedYuvBuffer) {
//Camera 传入的是 NV21
//转换成 MediaCodec 支持的格式
switch (mColorFormat) {
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar://对应Camera预览格式I420(YV21/YUV420P)
YUVEngine.Nv21ToI420(data, yuvBuffer, mWidth, mHeight);
YUVEngine.I420ClockWiseRotate90(yuvBuffer, mWidth, mHeight, rotatedYuvBuffer, mOutWidth, mOutHeight);
//Log.i("transferFrameData", "COLOR_FormatYUV420Planar");
break;
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar: //对应Camera预览格式NV12
YUVEngine.Nv21ToNv12(data, yuvBuffer, mWidth, mHeight);
YUVEngine.Nv12ClockWiseRotate90(yuvBuffer, mWidth, mHeight, rotatedYuvBuffer, mOutWidth, mOutHeight);
//Log.i("transferFrameData", "COLOR_FormatYUV420SemiPlanar");
break;
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedSemiPlanar://对应Camera预览格式NV21
System.arraycopy(data, 0, yuvBuffer, 0, mWidth * mHeight * 3 / 2);
YUVEngine.Nv21ClockWiseRotate90(yuvBuffer, mWidth, mHeight, rotatedYuvBuffer, mOutWidth, mOutHeight);
//Log.i("transferFrameData", "COLOR_FormatYUV420PackedSemiPlanar");
break;
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedPlanar: ////对应Camera预览格式YV12
YUVEngine.Nv21ToYV12(data, yuvBuffer, mWidth, mHeight);
YUVEngine.Yv12ClockWiseRotate90(yuvBuffer, mWidth, mHeight, rotatedYuvBuffer, mOutWidth, mOutHeight);
//Log.i("transferFrameData", "COLOR_FormatYUV420PackedPlanar");
break;
}
return rotatedYuvBuffer;
}
private MediaCodecInfo selectCodecInfo() {
int numCodecs = MediaCodecList.getCodecCount();
for (int i = 0; i < numCodecs; i++) {
MediaCodecInfo codecInfo = MediaCodecList.getCodecInfoAt(i);
if (!codecInfo.isEncoder()) {
continue;
}
String[] types = codecInfo.getSupportedTypes();
for (int j = 0; j < types.length; j++) {
if (types[j].equalsIgnoreCase(com.example.dplayer.mediacodec.h264.H264Encoder.VIDEO_MIME_TYPE)) {
return codecInfo;
}
}
}
return null;
}
//查询支持的输入格式
private int selectColorFormat(MediaCodecInfo codecInfo) {
if (codecInfo == null) {
return -1;
}
MediaCodecInfo.CodecCapabilities capabilities = codecInfo.getCapabilitiesForType(com.example.dplayer.mediacodec.h264.H264Encoder.VIDEO_MIME_TYPE);
int[] colorFormats = capabilities.colorFormats;
for (int i = 0; i < colorFormats.length; i++) {
if (isRecognizedFormat(colorFormats[i])) {
return colorFormats[i];
}
}
return -1;
}
private boolean isRecognizedFormat(int colorFormat) {
switch (colorFormat) {
// these are the formats we know how to handle for this test
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420Planar://对应Camera预览格式I420(YV21/YUV420P)
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420SemiPlanar: //对应Camera预览格式NV12
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedSemiPlanar://对应Camera预览格式NV21
case MediaCodecInfo.CodecCapabilities.COLOR_FormatYUV420PackedPlanar: {////对应Camera预览格式YV12
return true;
}
default:
return false;
}
}
}
5. 合成 MP4
由于 MediaMuxer 需要先 addTrack 才能 start ,其音频解码回调和视频解码回调处于不同的线程，因此，使用 object.wait 来等待所有数据完成 addTrack 。
public class Mp4Record implements H264VideoRecord.Callback, AacAudioRecord.Callback {
private static int index = 0;
private H264VideoRecord mH264VideoRecord;
private AacAudioRecord mAacAudioRecord;
private MediaMuxer mMediaMuxer;
private boolean mHasStartMuxer;
private boolean mHasStopAudio;
private boolean mHasStopVideo;
private int mVideoTrackIndex = -1;
private int mAudioTrackIndex = -1;
private final Object mLock;
private BlockingQueue<AVData> mDataBlockingQueue;
private volatile boolean mIsRecoding;
public Mp4Record(Activity activity, SurfaceView surfaceView, int audioSource, int sampleRateInHz, int channelConfig, int audioFormat, int bufferSizeInBytes, String path) {
mH264VideoRecord = new H264VideoRecord(activity, surfaceView);
mAacAudioRecord = new AacAudioRecord(audioSource, sampleRateInHz, channelConfig, audioFormat, bufferSizeInBytes);
mH264VideoRecord.setCallback(this);
mAacAudioRecord.setCallback(this);
try {
mMediaMuxer = new MediaMuxer(path, MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
} catch (IOException e) {
e.printStackTrace();
}
mHasStartMuxer = false;
mLock = new Object();
mDataBlockingQueue = new LinkedBlockingQueue<>();
}
public void start() {
mIsRecoding = true;
mAacAudioRecord.start();
mH264VideoRecord.start();
}
public void stop() {
mAacAudioRecord.stop();
mH264VideoRecord.stop();
mIsRecoding = false;
}
@Override
public void outputAudio(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
writeMediaData(mAudioTrackIndex, byteBuffer, bufferInfo);
}
@Override
public void outputMediaFormat(int type, MediaFormat mediaFormat) {
checkMediaFormat(type, mediaFormat);
}
@Override
public void outputVideo(ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
writeMediaData(mVideoTrackIndex, byteBuffer, bufferInfo);
}
private void writeMediaData(int trackIndex, ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
mDataBlockingQueue.add(new AVData(index++, trackIndex, byteBuffer, bufferInfo));
}
private void checkMediaFormat(int type, MediaFormat mediaFormat) {
synchronized (mLock) {
if (type == AAC_ENCODER) {
mAudioTrackIndex = mMediaMuxer.addTrack(mediaFormat);
}
if (type == H264_ENCODER) {
mVideoTrackIndex = mMediaMuxer.addTrack(mediaFormat);
}
startMediaMuxer();
}
}
private void startMediaMuxer() {
if (mHasStartMuxer) {
return;
}
if (mAudioTrackIndex != -1 && mVideoTrackIndex != -1) {
Log.e(TAG, "video track index:" + mVideoTrackIndex + "audio track index:" + mAudioTrackIndex);
mMediaMuxer.start();
mHasStartMuxer = true;
new Thread(new Runnable() {
@Override
public void run() {
while (mIsRecoding || !mDataBlockingQueue.isEmpty()) {
AVData avData = mDataBlockingQueue.poll();
if (avData == null) {
continue;
}
boolean keyFrame = (avData.bufferInfo.flags & MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0;
Log.e(TAG, avData.index + "trackIndex:" + avData.trackIndex + ",writeSampleData:" + keyFrame);
mMediaMuxer.writeSampleData(avData.trackIndex, avData.byteBuffer, avData.bufferInfo);
}
}
}).start();
mLock.notifyAll();
} else {
try {
mLock.wait();
} catch (InterruptedException e) {
}
}
}
@Override
public void onStop(int type) {
synchronized (mLock) {
if (type == H264_ENCODER) {
mHasStopVideo = true;
}
if (type == AAC_ENCODER) {
mHasStopAudio = true;
}
if (mHasStopAudio && mHasStopVideo && mHasStartMuxer) {
mHasStartMuxer = false;
mMediaMuxer.stop();
}
}
}
private class AVData {
int index = 0;
int trackIndex;
ByteBuffer byteBuffer;
MediaCodec.BufferInfo bufferInfo;
public AVData(int index, int trackIndex, ByteBuffer byteBuffer, MediaCodec.BufferInfo bufferInfo) {
this.index = index;
this.trackIndex = trackIndex;
this.byteBuffer = byteBuffer;
this.bufferInfo = bufferInfo;
boolean keyFrame = (bufferInfo.flags & MediaCodec.BUFFER_FLAG_KEY_FRAME) != 0;
Log.e(TAG, index + "trackIndex:" + trackIndex + ",AVData:" + keyFrame);
}
}
}
6. 遇到的问题
录制后的视频播放很快
原因是视频掉帧，通过修改关键帧参数解决
mMediaFormat.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, 5);
MediaMuxer 报 Video skip non-key frame
原因是第一个视频关键帧没有写入，因为处于不同的线程，放入队列中后，原始的 BufferInfo 被释放
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