feat: add copy method for NativeI420Buffer and VideoFrame

Author: devopvoid

webrtc-jni/src/main/cpp/include/JNI_NativeI420Buffer.h

@@ -33,6 +33,24 @@ JNIEXPORT jobject JNICALL Java_dev_onvoid_webrtc_media_video_NativeI420Buffer_al
 	return jBuffer.release();
 }
 
+JNIEXPORT jobject JNICALL Java_dev_onvoid_webrtc_media_video_NativeI420Buffer_copy
+(JNIEnv* env, jclass caller, jint width, jint height, jobject jSrcY, jint srcStrideY,
+	jobject jSrcU, jint srcStrideU, jobject jSrcV, jint srcStrideV)
+{
+	const uint8_t * src_y = static_cast<uint8_t*>(env->GetDirectBufferAddress(jSrcY));
+	const uint8_t * src_u = static_cast<uint8_t*>(env->GetDirectBufferAddress(jSrcU));
+	const uint8_t * src_v = static_cast<uint8_t*>(env->GetDirectBufferAddress(jSrcV));
+
+	webrtc::scoped_refptr<webrtc::I420BufferInterface> i420Buffer = webrtc::I420Buffer::Copy(width, height,
+		src_y, srcStrideY, src_u, srcStrideU, src_v, srcStrideV);
+
+	jni::JavaLocalRef<jobject> jBuffer = jni::I420Buffer::toJava(env, i420Buffer);
+
+	i420Buffer->AddRef();
+
+	return jBuffer.release();
+}
+
 JNIEXPORT void JNICALL Java_dev_onvoid_webrtc_media_video_NativeI420Buffer_cropAndScale
 (JNIEnv * env, jclass caller, jobject jSrcY, jint srcStrideY, jobject jSrcU, jint srcStrideU,
 	jobject jSrcV, jint srcStrideV, jint cropX, jint cropY, jint cropW, jint cropH,

webrtc-jni/src/main/cpp/src/JNI_NativeI420Buffer.cpp

@@ -18,9 +18,9 @@
 
 /**
  * Interface for ref counted objects in WebRTC. These objects have significant
- * resources that need to be freed when they are no longer in use. Each objects
+ * resources that need to be freed when they are no longer in use. Each object
  * starts with ref count of one when created. If a reference is passed as a
- * parameter to a method, the caller has ownesrship of the object by default -
+ * parameter to a method, the caller has ownership of the object by default -
  * calling release is not necessary unless retain is called.
  */
 public interface RefCounted {

webrtc/src/main/java/dev/onvoid/webrtc/internal/RefCounted.java

@@ -94,8 +94,6 @@ public int getHeight() {
 
 	@Override
 	public I420Buffer toI420() {
-//		retain();
-		
 	    return this;
 	}
 
@@ -112,11 +110,26 @@ public String toString() {
 						width, height);
 	}
 
+	/**
+	 * Creates a copy of this I420 buffer. This method performs a deep copy of all data in the buffer.
+	 *
+	 * @return A new NativeI420Buffer instance with the same dimensions and data as this buffer.
+	 */
+	public NativeI420Buffer copy() {
+		return copy(width, height, dataY.slice(), strideY, dataU.slice(), strideU, dataV.slice(), strideV);
+	}
+
 	/**
 	 * Allocates an empty I420Buffer suitable for an image of the given dimensions.
 	 */
 	public static native NativeI420Buffer allocate(int width, int height);
 
+	/**
+	 * Creates a copy of an I420 buffer with the given dimensions and data.
+	 */
+	private static native NativeI420Buffer copy(int width, int height, ByteBuffer dataY, int strideY, ByteBuffer dataU,
+												int strideU, ByteBuffer dataV, int strideV);
+
 	/**
 	 * Wraps existing ByteBuffers into NativeI420Buffer object without copying the
 	 * contents.
@@ -159,23 +172,17 @@ private static VideoFrameBuffer cropAndScale(final I420Buffer buffer, int cropX,
 			dataU.position(cropX / 2 + cropY / 2 * buffer.getStrideU());
 			dataV.position(cropX / 2 + cropY / 2 * buffer.getStrideV());
 
-//			buffer.retain();
-
 			return wrap(scaleWidth, scaleHeight, dataY.slice(), buffer.getStrideY(), dataU.slice(),
 					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;
 	}
 

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

@@ -39,8 +39,6 @@ public static void convertFromI420(VideoFrameBuffer src, byte[] dst, FourCC four
 				dst,
 				i420.getWidth(), i420.getHeight(),
 				fourCC.value());
-		
-//		i420.release();
 	}
 
 	public static void convertFromI420(VideoFrameBuffer src, ByteBuffer dst, FourCC fourCC) throws Exception {
@@ -63,7 +61,7 @@ public static void convertFromI420(VideoFrameBuffer src, ByteBuffer dst, FourCC
 					fourCC.value());
 		}
 		else {
-			byte[] arrayBuffer = null;
+			byte[] arrayBuffer;
 
 			if (dst.hasArray()) {
 				arrayBuffer = dst.array();
@@ -81,8 +79,6 @@ public static void convertFromI420(VideoFrameBuffer src, ByteBuffer dst, FourCC
 					i420.getWidth(), i420.getHeight(),
 					fourCC.value());
 		}
-		
-//		i420.release();
 	}
 
 	private native static void I420toByteArray(

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

@@ -18,21 +18,20 @@
 
 import dev.onvoid.webrtc.internal.RefCounted;
 
+/**
+ * Represents a video frame with an associated frame buffer and metadata.
+ * This class implements reference counting to manage memory for video frames.
+ * Video frames contain buffer data along with rotation and timestamp information.
+ */
 public class VideoFrame implements RefCounted {
 
-	/**
-	 * The underlying frame buffer.
-	 */
+	/** The underlying frame buffer. */
 	public final VideoFrameBuffer buffer;
 
-	/**
-	 * Rotation of the frame in degrees.
-	 */
+	/** Rotation of the frame in degrees. */
 	public final int rotation;
 
-	/**
-	 * Timestamp of the frame in nano seconds.
-	 */
+	/** Timestamp of the frame in nanoseconds. */
 	public final long timestampNs;
 
 
@@ -49,6 +48,17 @@ private VideoFrame(VideoFrameBuffer buffer, int rotation, long timestampNs) {
 		this.timestampNs = timestampNs;
 	}
 
+	/**
+	 * Creates a deep copy of this VideoFrame. The new frame will have its own copy of the buffer data.
+	 *
+	 * @return A new VideoFrame with a copy of the buffer data.
+	 */
+	public VideoFrame copy() {
+		NativeI420Buffer nativeBuffer = (NativeI420Buffer) buffer;
+
+		return new VideoFrame(nativeBuffer.copy(), rotation, timestampNs);
+	}
+
 	@Override
 	public void retain() {
 		buffer.retain();

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

@@ -39,7 +39,7 @@ public interface VideoFrameBuffer extends RefCounted {
 	I420Buffer toI420();
 
 	/**
-	 * Crops a region defined by |cropx|, |cropY|, |cropWidth| and |cropHeight|.
+	 * Crops a region defined by |cropX|, |cropY|, |cropWidth| and |cropHeight|.
 	 * Scales it to size |scaleWidth| x |scaleHeight|.
 	 */
 	VideoFrameBuffer cropAndScale(int cropX, int cropY, int cropWidth,