fix: crashes caused by video frame conversion

Author: devopvoid

webrtc-jni/src/main/cpp/src/api/VideoTrackSink.cpp

@@ -38,14 +38,21 @@ namespace jni
 		rtc::scoped_refptr<webrtc::VideoFrameBuffer> buffer = frame.video_frame_buffer();
 		rtc::scoped_refptr<webrtc::I420BufferInterface> i420Buffer = buffer->ToI420();
 
+		if (i420Buffer == nullptr) {
+			return;
+		}
+
+		rtc::scoped_refptr<webrtc::I420Buffer> i420BufferCopy = webrtc::I420Buffer::Copy(*i420Buffer);
+		i420BufferCopy->AddRef();
+
 //		if (frame.rotation() != webrtc::kVideoRotation_0) {
 //			i420Buffer = webrtc::I420Buffer::Rotate(*i420Buffer, frame.rotation());
 //		}
 
 		jint rotation = static_cast<jint>(frame.rotation());
 		jlong timestamp = frame.timestamp_us() * rtc::kNumNanosecsPerMicrosec;
 
-		JavaLocalRef<jobject> jBuffer = I420Buffer::toJava(env, i420Buffer);
+		JavaLocalRef<jobject> jBuffer = I420Buffer::toJava(env, i420BufferCopy);
 		jobject jFrame = env->NewObject(javaFrameClass->cls, javaFrameClass->ctor, jBuffer.get(), rotation, timestamp);
 
 		env->CallVoidMethod(sink, javaClass->onFrame, jFrame);

webrtc/src/main/java/dev/onvoid/webrtc/media/video/NativeI420Buffer.java

@@ -165,13 +165,17 @@ private static VideoFrameBuffer cropAndScale(final I420Buffer buffer, int cropX,
 					buffer.getStrideU(), dataV.slice(), buffer.getStrideV());
 		}
 
+		buffer.retain();
+
 		I420Buffer newBuffer = allocate(scaleWidth, scaleHeight);
-		
+
 		cropAndScale(buffer.getDataY(), buffer.getStrideY(), buffer.getDataU(), buffer.getStrideU(),
 				buffer.getDataV(), buffer.getStrideV(), cropX, cropY, cropWidth, cropHeight,
 				newBuffer.getDataY(), newBuffer.getStrideY(), newBuffer.getDataU(), newBuffer.getStrideU(),
 				newBuffer.getDataV(), newBuffer.getStrideV(), scaleWidth, scaleHeight);
-		
+
+		buffer.release();
+
 		return newBuffer;
 	}