Video only recording
I had a similar case in my project. At first, I tried WebRTC's default VideoFileRenderer but the video size was too big because no compression is applied.
I found this repository. It really helped in my case.
https://github.com/cloudwebrtc/flutter-webrtc
Here is a step by step guide. I've also made some adjustments.
Add this class to your project. It has lots of options to configure the final video format.
import android.media.MediaCodec;
import android.media.MediaCodecInfo;
import android.media.MediaFormat;
import android.media.MediaMuxer;
import android.os.Handler;
import android.os.HandlerThread;
import android.util.Log;
import android.view.Surface;
import org.webrtc.EglBase;
import org.webrtc.GlRectDrawer;
import org.webrtc.VideoFrame;
import org.webrtc.VideoFrameDrawer;
import org.webrtc.VideoSink;
import java.io.IOException;
import java.nio.ByteBuffer;
class FileEncoder implements VideoSink {
private static final String TAG = "FileRenderer";
private final HandlerThread renderThread;
private final Handler renderThreadHandler;
private int outputFileWidth = -1;
private int outputFileHeight = -1;
private ByteBuffer[] encoderOutputBuffers;
private EglBase eglBase;
private EglBase.Context sharedContext;
private VideoFrameDrawer frameDrawer;
private static final String MIME_TYPE = "video/avc"; // H.264 Advanced Video Coding
private static final int FRAME_RATE = 30; // 30fps
private static final int IFRAME_INTERVAL = 5; // 5 seconds between I-frames
private MediaMuxer mediaMuxer;
private MediaCodec encoder;
private MediaCodec.BufferInfo bufferInfo;
private int trackIndex = -1;
private boolean isRunning = true;
private GlRectDrawer drawer;
private Surface surface;
FileEncoder(String outputFile, final EglBase.Context sharedContext) throws IOException {
renderThread = new HandlerThread(TAG + "RenderThread");
renderThread.start();
renderThreadHandler = new Handler(renderThread.getLooper());
bufferInfo = new MediaCodec.BufferInfo();
this.sharedContext = sharedContext;
mediaMuxer = new MediaMuxer(outputFile,
MediaMuxer.OutputFormat.MUXER_OUTPUT_MPEG_4);
}
private void initVideoEncoder() {
MediaFormat format = MediaFormat.createVideoFormat(MIME_TYPE, 1280, 720);
format.setInteger(MediaFormat.KEY_COLOR_FORMAT,
MediaCodecInfo.CodecCapabilities.COLOR_FormatSurface);
format.setInteger(MediaFormat.KEY_BIT_RATE, 6000000);
format.setInteger(MediaFormat.KEY_FRAME_RATE, FRAME_RATE);
format.setInteger(MediaFormat.KEY_I_FRAME_INTERVAL, IFRAME_INTERVAL);
try {
encoder = MediaCodec.createEncoderByType(MIME_TYPE);
encoder.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
renderThreadHandler.post(() -> {
eglBase = EglBase.create(sharedContext, EglBase.CONFIG_RECORDABLE);
surface = encoder.createInputSurface();
eglBase.createSurface(surface);
eglBase.makeCurrent();
drawer = new GlRectDrawer();
});
} catch (Exception e) {
Log.wtf(TAG, e);
}
}
@Override
public void onFrame(VideoFrame frame) {
frame.retain();
if (outputFileWidth == -1) {
outputFileWidth = frame.getRotatedWidth();
outputFileHeight = frame.getRotatedHeight();
initVideoEncoder();
}
renderThreadHandler.post(() -> renderFrameOnRenderThread(frame));
}
private void renderFrameOnRenderThread(VideoFrame frame) {
if (frameDrawer == null) {
frameDrawer = new VideoFrameDrawer();
}
frameDrawer.drawFrame(frame, drawer, null, 0, 0, outputFileWidth, outputFileHeight);
frame.release();
drainEncoder();
eglBase.swapBuffers();
}
/**
* Release all resources. All already posted frames will be rendered first.
*/
void release() {
isRunning = false;
renderThreadHandler.post(() -> {
if (encoder != null) {
encoder.stop();
encoder.release();
}
eglBase.release();
mediaMuxer.stop();
mediaMuxer.release();
renderThread.quit();
});
}
private boolean encoderStarted = false;
private volatile boolean muxerStarted = false;
private long videoFrameStart = 0;
private void drainEncoder() {
if (!encoderStarted) {
encoder.start();
encoderOutputBuffers = encoder.getOutputBuffers();
encoderStarted = true;
return;
}
while (true) {
int encoderStatus = encoder.dequeueOutputBuffer(bufferInfo, 10000);
if (encoderStatus == MediaCodec.INFO_TRY_AGAIN_LATER) {
break;
} else if (encoderStatus == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED) {
// not expected for an encoder
encoderOutputBuffers = encoder.getOutputBuffers();
Log.e(TAG, "encoder output buffers changed");
} else if (encoderStatus == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED) {
// not expected for an encoder
MediaFormat newFormat = encoder.getOutputFormat();
Log.e(TAG, "encoder output format changed: " + newFormat);
trackIndex = mediaMuxer.addTrack(newFormat);
if (!muxerStarted) {
mediaMuxer.start();
muxerStarted = true;
}
if (!muxerStarted)
break;
} else if (encoderStatus < 0) {
Log.e(TAG, "unexpected result fr om encoder.dequeueOutputBuffer: " + encoderStatus);
} else { // encoderStatus >= 0
try {
ByteBuffer encodedData = encoderOutputBuffers[encoderStatus];
if (encodedData == null) {
Log.e(TAG, "encoderOutputBuffer " + encoderStatus + " was null");
break;
}
// It's usually necessary to adjust the ByteBuffer values to match BufferInfo.
encodedData.position(bufferInfo.offset);
encodedData.limit(bufferInfo.offset + bufferInfo.size);
if (videoFrameStart == 0 && bufferInfo.presentationTimeUs != 0) {
videoFrameStart = bufferInfo.presentationTimeUs;
}
bufferInfo.presentationTimeUs -= videoFrameStart;
if (muxerStarted)
mediaMuxer.writeSampleData(trackIndex, encodedData, bufferInfo);
isRunning = isRunning && (bufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) == 0;
encoder.releaseOutputBuffer(encoderStatus, false);
if ((bufferInfo.flags & MediaCodec.BUFFER_FLAG_END_OF_STREAM) != 0) {
break;
}
} catch (Exception e) {
Log.wtf(TAG, e);
break;
}
}
}
}
private long presTime = 0L;
}
Now on your Activity/Fragment class
Declare a variable of the above class
FileEncoder recording;
When you receive the stream you want to record(remote or local) you can initialize the recording.
FileEncoder recording = new FileEncoder("path/to/video", rootEglBase.eglBaseContext)
remoteVideoTrack.addSink(recording)
When the call session ends, you need to stop and release the recording.
remoteVideoTrack.removeSink(recording)
recording.release()
This is enough to record the video but without audio.
Video & Audio recording
To record local peer's audio you need to consume this class(https://webrtc.googlesource.com/src/+/master/examples/androidapp/src/org/appspot/apprtc/RecordedAudioToFileController.java). But first you need to setup an AudioDeviceModule object
AudioDeviceModule adm = createJavaAudioDevice()
peerConnectionFactory = PeerConnectionFactory.builder()
.setOptions(options)
.setAudioDeviceModule(adm)
.setVideoEncoderFactory(defaultVideoEncoderFactory)
.setVideoDecoderFactory(defaultVideoDecoderFactory)
.createPeerConnectionFactory()
adm.release()
private AudioDeviceModule createJavaAudioDevice() {
//Implement AudioRecordErrorCallback
//Implement AudioTrackErrorCallback
return JavaAudioDeviceModule.builder(this)
.setSamplesReadyCallback(audioRecorder)
//Default audio source is Voice Communication which is good for VoIP sessions. You can change to the audio source you want.
.setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION)
.setAudioRecordErrorCallback(audioRecordErrorCallback)
.setAudioTrackErrorCallback(audioTrackErrorCallback)
.createAudioDeviceModule()
}
Merge audio and video
Add this dependency
implementation 'com.googlecode.mp4parser:isoparser:1.1.22'
Then add this piece to your code when your call finishes. Make sure that video and audio recording are stopped and released properly.
try {
Movie video;
video = MovieCreator.build("path/to/recorded/video");
Movie audio;
audio = MovieCreator.build("path/to/recorded/audio");
Track audioTrack = audio.getTracks().get(0)
video.addTrack(audioTrack);
Container out = new DefaultMp4Builder().build(video);
FileChannel fc = new FileOutputStream(new File("path/to/final/output")).getChannel();
out.writeContainer(fc);
fc.close();
} catch (IOException e) {
e.printStackTrace();
}
I know this isn't the best solution for recording audio and video in an Android WebRTC video call. If someone knows how to extract audio using WebRTC please add a comment.
