Merge pull request #6573 from fabianishere/feat/mac-virtualcam

mac-virtualcam: Avoid transcoding where possible

plugins/mac-virtualcam/src/dal-plugin/CMSampleBufferUtils.h

@@ -7,16 +7,6 @@
 
 #include <CoreMediaIO/CMIOSampleBuffer.h>
 
-OSStatus CMSampleBufferCreateFromData(NSSize size,
-				      CMSampleTimingInfo timingInfo,
-				      UInt64 sequenceNumber, NSData *data,
-				      CMSampleBufferRef *sampleBuffer);
-
-OSStatus CMSampleBufferCreateFromDataNoCopy(NSSize size,
-					    CMSampleTimingInfo timingInfo,
-					    UInt64 sequenceNumber, NSData *data,
-					    CMSampleBufferRef *sampleBuffer);
-
 CMSampleTimingInfo CMSampleTimingInfoForTimestamp(uint64_t timestampNanos,
 						  uint32_t fpsNumerator,
 						  uint32_t fpsDenominator);

plugins/mac-virtualcam/src/dal-plugin/CMSampleBufferUtils.mm

@@ -7,165 +7,6 @@
 
 #import "CMSampleBufferUtils.h"
 
-#include "Logging.h"
-
-/*!
-CMSampleBufferCreateFromData
-
-Creates a CMSampleBuffer by copying bytes from NSData into a CVPixelBuffer.
-*/
-OSStatus CMSampleBufferCreateFromData(NSSize size,
-				      CMSampleTimingInfo timingInfo,
-				      UInt64 sequenceNumber, NSData *data,
-				      CMSampleBufferRef *sampleBuffer)
-{
-	OSStatus err = noErr;
-
-	// Create an empty pixel buffer
-	CVPixelBufferRef pixelBuffer;
-	err = CVPixelBufferCreate(kCFAllocatorDefault, size.width, size.height,
-				  kCVPixelFormatType_422YpCbCr8, nil,
-				  &pixelBuffer);
-	if (err != noErr) {
-		DLog(@"CVPixelBufferCreate err %d", err);
-		return err;
-	}
-
-	// Generate the video format description from that pixel buffer
-	CMFormatDescriptionRef format;
-	err = CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixelBuffer,
-							   &format);
-	if (err != noErr) {
-		DLog(@"CMVideoFormatDescriptionCreateForImageBuffer err %d",
-		     err);
-		return err;
-	}
-
-	// Copy memory into the pixel buffer
-	CVPixelBufferLockBaseAddress(pixelBuffer, 0);
-	uint8_t *dest =
-		(uint8_t *)CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
-	uint8_t *src = (uint8_t *)data.bytes;
-
-	size_t destBytesPerRow =
-		CVPixelBufferGetBytesPerRowOfPlane(pixelBuffer, 0);
-	size_t srcBytesPerRow = size.width * 2;
-
-	// Sometimes CVPixelBufferCreate will create a pixelbuffer that's a different
-	// size than necessary to hold the frame (probably for some optimization reason).
-	// If that is the case this will do a row-by-row copy into the buffer.
-	if (destBytesPerRow == srcBytesPerRow) {
-		memcpy(dest, src, data.length);
-	} else {
-		for (int line = 0; line < size.height; line++) {
-			memcpy(dest, src, srcBytesPerRow);
-			src += srcBytesPerRow;
-			dest += destBytesPerRow;
-		}
-	}
-
-	CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
-
-	err = CMIOSampleBufferCreateForImageBuffer(kCFAllocatorDefault,
-						   pixelBuffer, format,
-						   &timingInfo, sequenceNumber,
-						   0, sampleBuffer);
-	CFRelease(format);
-	CFRelease(pixelBuffer);
-
-	if (err != noErr) {
-		DLog(@"CMIOSampleBufferCreateForImageBuffer err %d", err);
-		return err;
-	}
-
-	return noErr;
-}
-
-static void releaseNSData(void *o, void *, size_t)
-{
-	NSData *data = (__bridge_transfer NSData *)o;
-	data = nil; // Assuming ARC is enabled
-}
-
-// From https://stackoverflow.com/questions/26158253/how-to-create-a-cmblockbufferref-from-nsdata
-OSStatus createReadonlyBlockBuffer(CMBlockBufferRef *result, NSData *data)
-{
-	CMBlockBufferCustomBlockSource blockSource = {
-		.version = kCMBlockBufferCustomBlockSourceVersion,
-		.AllocateBlock = NULL,
-		.FreeBlock = &releaseNSData,
-		.refCon = (__bridge_retained void *)data,
-	};
-	return CMBlockBufferCreateWithMemoryBlock(NULL, (void *)data.bytes,
-						  data.length, NULL,
-						  &blockSource, 0, data.length,
-						  0, result);
-}
-
-/*!
- CMSampleBufferCreateFromDataNoCopy
-
- Creates a CMSampleBuffer by using the bytes directly from NSData (without copying them).
- Seems to mostly work but does not work at full resolution in OBS for some reason (which prevents loopback testing).
- */
-OSStatus CMSampleBufferCreateFromDataNoCopy(NSSize size,
-					    CMSampleTimingInfo timingInfo,
-					    UInt64 sequenceNumber, NSData *data,
-					    CMSampleBufferRef *sampleBuffer)
-{
-	OSStatus err = noErr;
-
-	CMBlockBufferRef dataBuffer;
-	createReadonlyBlockBuffer(&dataBuffer, data);
-
-	// Magic format properties snagged from https://github.com/lvsti/CoreMediaIO-DAL-Example/blob/0392cbf27ed33425a1a5bd9f495b2ccec8f20501/Sources/Extras/CoreMediaIO/DeviceAbstractionLayer/Devices/Sample/PlugIn/CMIO_DP_Sample_Stream.cpp#L830
-	NSDictionary *extensions = @{
-		@"com.apple.cmio.format_extension.video.only_has_i_frames":
-			@YES,
-		(__bridge NSString *)
-		kCMFormatDescriptionExtension_FieldCount: @1,
-		(__bridge NSString *)
-		kCMFormatDescriptionExtension_ColorPrimaries:
-			(__bridge NSString *)
-				kCMFormatDescriptionColorPrimaries_SMPTE_C,
-		(__bridge NSString *)
-		kCMFormatDescriptionExtension_TransferFunction: (
-			__bridge NSString *)
-			kCMFormatDescriptionTransferFunction_ITU_R_709_2,
-		(__bridge NSString *)
-		kCMFormatDescriptionExtension_YCbCrMatrix: (__bridge NSString *)
-			kCMFormatDescriptionYCbCrMatrix_ITU_R_601_4,
-		(__bridge NSString *)
-		kCMFormatDescriptionExtension_BytesPerRow: @(size.width * 2),
-		(__bridge NSString *)kCMFormatDescriptionExtension_FormatName:
-			@"Component Video - CCIR-601 uyvy",
-		(__bridge NSString *)kCMFormatDescriptionExtension_Version: @2,
-	};
-
-	CMFormatDescriptionRef format;
-	err = CMVideoFormatDescriptionCreate(
-		NULL, kCMVideoCodecType_422YpCbCr8, size.width, size.height,
-		(__bridge CFDictionaryRef)extensions, &format);
-	if (err != noErr) {
-		DLog(@"CMVideoFormatDescriptionCreate err %d", err);
-		return err;
-	}
-
-	size_t dataSize = data.length;
-	err = CMIOSampleBufferCreate(kCFAllocatorDefault, dataBuffer, format, 1,
-				     1, &timingInfo, 1, &dataSize,
-				     sequenceNumber, 0, sampleBuffer);
-	CFRelease(format);
-	CFRelease(dataBuffer);
-
-	if (err != noErr) {
-		DLog(@"CMIOSampleBufferCreate err %d", err);
-		return err;
-	}
-
-	return noErr;
-}
-
 CMSampleTimingInfo CMSampleTimingInfoForTimestamp(uint64_t timestampNanos,
 						  uint32_t fpsNumerator,
 						  uint32_t fpsDenominator)
@@ -175,7 +16,7 @@ CMSampleTimingInfo CMSampleTimingInfoForTimestamp(uint64_t timestampNanos,
 	// timestamps and scales like mach_absolute_time() and NSEC_PER_SEC will work for display, but will error out
 	// when trying to record.
 	//
-	// 600 is a commmon default in Apple's docs https://developer.apple.com/documentation/avfoundation/avmutablemovie/1390622-timescale
+	// 600 is a common default in Apple's docs https://developer.apple.com/documentation/avfoundation/avmutablemovie/1390622-timescale
 	CMTimeScale scale = 600;
 	CMSampleTimingInfo timing;
 	timing.duration =

plugins/mac-virtualcam/src/dal-plugin/CMakeLists.txt

@@ -1,15 +1,12 @@
-# Build DAL plugin universal to ensure compatibility with Rosetta-translated
-# apps on arm64 hosts
-set(CMAKE_OSX_ARCHITECTURES "x86_64;arm64")
-
 project(mac-dal-plugin)
 
 find_library(COCOA Cocoa)
 find_library(COREMEDIA CoreMedia)
 find_library(COREMEDIAIO CoreMediaIO)
 find_library(COREVIDEO CoreVideo)
+find_library(IOSURFACE IOSurface)
 
-mark_as_advanced(COCOA COREMEDIA COREMEDIAIO COREVIDEO)
+mark_as_advanced(COCOA COREMEDIA COREMEDIAIO COREVIDEO IOSURFACE)
 
 add_library(mac-dal-plugin MODULE)
 add_library(OBS::mac-dal-plugin ALIAS mac-dal-plugin)
@@ -41,8 +38,9 @@ target_include_directories(
 
 target_compile_options(mac-dal-plugin PRIVATE -fobjc-arc -fobjc-weak)
 
-target_link_libraries(mac-dal-plugin PRIVATE ${COCOA} ${COREMEDIA}
-                                             ${COREMEDIAIO} ${COREVIDEO})
+target_link_libraries(
+  mac-dal-plugin PRIVATE ${COCOA} ${COREMEDIA} ${COREMEDIAIO} ${COREVIDEO}
+                         ${IOSURFACE})
 
 set(MACOSX_PLUGIN_BUNDLE_TYPE "BNDL")
 target_sources(mac-dal-plugin PRIVATE placeholder.png)
@@ -58,6 +56,10 @@ set_target_properties(
              FOLDER "plugins"
              VERSION "0"
              SOVERSION "0"
+             # Force the DAL plugin to be built for arm64e as well. Note that
+             # we cannot build OBS for arm64e, since its libraries are not
+             # built for this architecture at the moment.
+             OSX_ARCHITECTURES "x86_64;arm64;arm64e"
              LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/../../"
              MACOSX_BUNDLE_INFO_PLIST
              "${CMAKE_SOURCE_DIR}/cmake/bundle/macOS/Virtualcam-Info.plist.in")

plugins/mac-virtualcam/src/dal-plugin/OBSDALMachClient.h

@@ -6,16 +6,16 @@
 //
 
 #import <Foundation/Foundation.h>
+#import <CoreVideo/CoreVideo.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
 @protocol MachClientDelegate
 
-- (void)receivedFrameWithSize:(NSSize)size
-		    timestamp:(uint64_t)timestamp
-		 fpsNumerator:(uint32_t)fpsNumerator
-	       fpsDenominator:(uint32_t)fpsDenominator
-		    frameData:(NSData *)frameData;
+- (void)receivedPixelBuffer:(CVPixelBufferRef)frame
+		  timestamp:(uint64_t)timestamp
+	       fpsNumerator:(uint32_t)fpsNumerator
+	     fpsDenominator:(uint32_t)fpsDenominator;
 - (void)receivedStop;
 
 @end

plugins/mac-virtualcam/src/dal-plugin/OBSDALMachClient.mm

@@ -101,29 +101,37 @@
 		break;
 	case MachMsgIdFrame:
 		VLog(@"Received frame message");
-		if (components.count >= 6) {
-			CGFloat width;
-			[components[0] getBytes:&width length:sizeof(width)];
-			CGFloat height;
-			[components[1] getBytes:&height length:sizeof(height)];
+		if (components.count >= 4) {
+			NSMachPort *framePort = (NSMachPort *)components[0];
+			IOSurfaceRef surface = IOSurfaceLookupFromMachPort(
+				[framePort machPort]);
+
+			CVPixelBufferRef frame;
+			CVPixelBufferCreateWithIOSurface(kCFAllocatorDefault,
+							 surface, NULL, &frame);
+
 			uint64_t timestamp;
-			[components[2] getBytes:&timestamp
+			[components[1] getBytes:&timestamp
 					 length:sizeof(timestamp)];
-			VLog(@"Received frame data: %fx%f (%llu)", width,
-			     height, timestamp);
-			NSData *frameData = components[3];
+
+			VLog(@"Received frame data: %zux%zu (%llu)",
+			     CVPixelBufferGetWidth(frame),
+			     CVPixelBufferGetHeight(frame), timestamp);
+
 			uint32_t fpsNumerator;
-			[components[4] getBytes:&fpsNumerator
+			[components[2] getBytes:&fpsNumerator
 					 length:sizeof(fpsNumerator)];
 			uint32_t fpsDenominator;
-			[components[5] getBytes:&fpsDenominator
+			[components[3] getBytes:&fpsDenominator
 					 length:sizeof(fpsDenominator)];
-			[self.delegate
-				receivedFrameWithSize:NSMakeSize(width, height)
-					    timestamp:timestamp
-					 fpsNumerator:fpsNumerator
-				       fpsDenominator:fpsDenominator
-					    frameData:frameData];
+
+			[self.delegate receivedPixelBuffer:frame
+						 timestamp:timestamp
+					      fpsNumerator:fpsNumerator
+					    fpsDenominator:fpsDenominator];
+
+			CVPixelBufferRelease(frame);
+			CFRelease(surface);
 		}
 		break;
 	case MachMsgIdStop:

plugins/mac-virtualcam/src/dal-plugin/OBSDALPlugIn.mm

@@ -203,19 +203,21 @@ typedef enum {
 
 #pragma mark - MachClientDelegate
 
-- (void)receivedFrameWithSize:(NSSize)size
-		    timestamp:(uint64_t)timestamp
-		 fpsNumerator:(uint32_t)fpsNumerator
-	       fpsDenominator:(uint32_t)fpsDenominator
-		    frameData:(NSData *)frameData
+- (void)receivedPixelBuffer:(CVPixelBufferRef)frame
+		  timestamp:(uint64_t)timestamp
+	       fpsNumerator:(uint32_t)fpsNumerator
+	     fpsDenominator:(uint32_t)fpsDenominator
 {
+	size_t width = CVPixelBufferGetWidth(frame);
+	size_t height = CVPixelBufferGetHeight(frame);
+
 	dispatch_sync(_stateQueue, ^{
 		if (_state == PlugInStateWaitingForServer) {
 			NSUserDefaults *defaults =
 				[NSUserDefaults standardUserDefaults];
-			[defaults setInteger:size.width
+			[defaults setInteger:(long)width
 				      forKey:kTestCardWidthKey];
-			[defaults setInteger:size.height
+			[defaults setInteger:(long)height
 				      forKey:kTestCardHeightKey];
 			[defaults setDouble:(double)fpsNumerator /
 					    (double)fpsDenominator
@@ -234,11 +236,10 @@ typedef enum {
 		dispatch_time(DISPATCH_TIME_NOW, 5.0 * NSEC_PER_SEC),
 		5.0 * NSEC_PER_SEC, (1ull * NSEC_PER_SEC) / 10);
 
-	[self.stream queueFrameWithSize:size
-			      timestamp:timestamp
-			   fpsNumerator:fpsNumerator
-			 fpsDenominator:fpsDenominator
-			      frameData:frameData];
+	[self.stream queuePixelBuffer:frame
+			    timestamp:timestamp
+			 fpsNumerator:fpsNumerator
+		       fpsDenominator:fpsDenominator];
 }
 
 - (void)receivedStop

plugins/mac-virtualcam/src/dal-plugin/OBSDALStream.h

@@ -18,6 +18,7 @@
 //  along with obs-mac-virtualcam. If not, see <http://www.gnu.org/licenses/>.
 
 #import "OBSDALObjectStore.h"
+#import <CoreVideo/CoreVideo.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -35,11 +36,10 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)stopServingDefaultFrames;
 
-- (void)queueFrameWithSize:(NSSize)size
-		 timestamp:(uint64_t)timestamp
-	      fpsNumerator:(uint32_t)fpsNumerator
-	    fpsDenominator:(uint32_t)fpsDenominator
-		 frameData:(NSData *)frameData;
+- (void)queuePixelBuffer:(CVPixelBufferRef)frame
+	       timestamp:(uint64_t)timestamp
+	    fpsNumerator:(uint32_t)fpsNumerator
+	  fpsDenominator:(uint32_t)fpsDenominator;
 
 @end
 

plugins/mac-virtualcam/src/dal-plugin/OBSDALStream.mm

@@ -349,11 +349,10 @@
 	}
 }
 
-- (void)queueFrameWithSize:(NSSize)size
-		 timestamp:(uint64_t)timestamp
-	      fpsNumerator:(uint32_t)fpsNumerator
-	    fpsDenominator:(uint32_t)fpsDenominator
-		 frameData:(NSData *)frameData
+- (void)queuePixelBuffer:(CVPixelBufferRef)frame
+	       timestamp:(uint64_t)timestamp
+	    fpsNumerator:(uint32_t)fpsNumerator
+	  fpsDenominator:(uint32_t)fpsDenominator
 {
 	if (CMSimpleQueueGetFullness(self.queue) >= 1.0) {
 		DLog(@"Queue is full, bailing out");
@@ -374,9 +373,34 @@
 	self.sequenceNumber = CMIOGetNextSequenceNumber(self.sequenceNumber);
 
 	CMSampleBufferRef sampleBuffer;
-	CMSampleBufferCreateFromData(size, timingInfo, self.sequenceNumber,
-				     frameData, &sampleBuffer);
-	CMSimpleQueueEnqueue(self.queue, sampleBuffer);
+
+	// Generate the video format description from that pixel buffer
+	CMVideoFormatDescriptionRef format;
+	err = CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault,
+							   frame, &format);
+	if (err != noErr) {
+		DLog(@"CMVideoFormatDescriptionCreateForImageBuffer err %d",
+		     err);
+		return;
+	}
+
+	err = CMIOSampleBufferCreateForImageBuffer(
+		kCFAllocatorDefault, frame, format, &timingInfo,
+		self.sequenceNumber, kCMIOSampleBufferNoDiscontinuities,
+		&sampleBuffer);
+
+	CFRelease(format);
+
+	if (err != noErr) {
+		DLog(@"CMIOSampleBufferCreateForImageBuffer err %d", err);
+		return;
+	}
+
+	err = CMSimpleQueueEnqueue(self.queue, sampleBuffer);
+	if (err != noErr) {
+		DLog(@"CMSimpleQueueEnqueue err %d", err);
+		return;
+	}
 
 	// Inform the clients that the queue has been altered
 	if (self.alteredProc != NULL) {
@@ -389,7 +413,8 @@
 {
 	CMVideoFormatDescriptionRef formatDescription;
 	OSStatus err = CMVideoFormatDescriptionCreate(
-		kCFAllocatorDefault, kCMVideoCodecType_422YpCbCr8,
+		kCFAllocatorDefault,
+		kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange,
 		self.testCardSize.width, self.testCardSize.height, NULL,
 		&formatDescription);
 	if (err != noErr) {
@@ -551,7 +576,14 @@
 
 - (BOOL)isPropertySettableWithAddress:(CMIOObjectPropertyAddress)address
 {
-	return false;
+	switch (address.mSelector) {
+	case kCMIOStreamPropertyFormatDescription:
+	case kCMIOStreamPropertyFrameRate:
+		// Suppress error logs complaining about the application not being able to set the desired format or frame rate.
+		return true;
+	default:
+		return false;
+	}
 }
 
 - (void)setPropertyDataWithAddress:(CMIOObjectPropertyAddress)address

plugins/mac-virtualcam/src/obs-plugin/CMakeLists.txt

@@ -1,8 +1,10 @@
 project(mac-virtualcam)
 
 find_library(APPKIT AppKit)
+find_library(COREVIDEO CoreVideo)
+find_library(IOSURFACE IOSurface)
 
-mark_as_advanced(APPKIT)
+mark_as_advanced(APPKIT COREVIDEO IOSURFACE)
 
 add_library(mac-virtualcam MODULE)
 add_library(OBS::virtualcam ALIAS mac-virtualcam)
@@ -15,8 +17,9 @@ target_include_directories(
   mac-virtualcam
   PRIVATE "$<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>/../common")
 
-target_link_libraries(mac-virtualcam PRIVATE OBS::libobs OBS::frontend-api
-                                             ${APPKIT})
+target_link_libraries(
+  mac-virtualcam PRIVATE OBS::libobs OBS::frontend-api ${APPKIT} ${COREVIDEO}
+                         ${IOSURFACE})
 
 target_compile_features(mac-virtualcam PRIVATE cxx_deleted_functions
                                                cxx_rvalue_references cxx_std_17)

plugins/mac-virtualcam/src/obs-plugin/OBSDALMachServer.h

@@ -6,6 +6,7 @@
 //
 
 #import <Foundation/Foundation.h>
+#import <CoreVideo/CoreVideo.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -16,11 +17,10 @@ NS_ASSUME_NONNULL_BEGIN
 /*!
  Will eventually be used for sending frames to all connected clients
  */
-- (void)sendFrameWithSize:(NSSize)size
-		timestamp:(uint64_t)timestamp
-	     fpsNumerator:(uint32_t)fpsNumerator
-	   fpsDenominator:(uint32_t)fpsDenominator
-	       frameBytes:(uint8_t *)frameBytes;
+- (void)sendPixelBuffer:(CVPixelBufferRef)frame
+	      timestamp:(uint64_t)timestamp
+	   fpsNumerator:(uint32_t)fpsNumerator
+	 fpsDenominator:(uint32_t)fpsDenominator;
 
 - (void)stop;
 

plugins/mac-virtualcam/src/obs-plugin/OBSDALMachServer.mm

@@ -7,6 +7,7 @@
 
 #import "OBSDALMachServer.h"
 #include <obs-module.h>
+#include <CoreVideo/CoreVideo.h>
 #include "MachProtocol.h"
 #include "Defines.h"
 
@@ -100,19 +101,24 @@
 				     receivePort:nil
 				      components:components];
 			message.msgid = msgId;
-			if (![message
+			if (![port isValid] ||
+			    ![message
 				    sendBeforeDate:
 					    [NSDate dateWithTimeIntervalSinceNow:
 							    1.0]]) {
 				blog(LOG_DEBUG,
 				     "failed to send message to %d, removing it from the clients!",
 				     ((NSMachPort *)port).machPort);
+
+				[port invalidate];
 				[removedPorts addObject:port];
 			}
 		} @catch (NSException *exception) {
 			blog(LOG_DEBUG,
 			     "failed to send message (exception) to %d, removing it from the clients!",
 			     ((NSMachPort *)port).machPort);
+
+			[port invalidate];
 			[removedPorts addObject:port];
 		}
 	}
@@ -121,23 +127,16 @@
 	[self.clientPorts minusSet:removedPorts];
 }
 
-- (void)sendFrameWithSize:(NSSize)size
-		timestamp:(uint64_t)timestamp
-	     fpsNumerator:(uint32_t)fpsNumerator
-	   fpsDenominator:(uint32_t)fpsDenominator
-	       frameBytes:(uint8_t *)frameBytes
+- (void)sendPixelBuffer:(CVPixelBufferRef)frame
+	      timestamp:(uint64_t)timestamp
+	   fpsNumerator:(uint32_t)fpsNumerator
+	 fpsDenominator:(uint32_t)fpsDenominator
 {
 	if ([self.clientPorts count] <= 0) {
 		return;
 	}
 
 	@autoreleasepool {
-		CGFloat width = size.width;
-		NSData *widthData = [NSData dataWithBytes:&width
-						   length:sizeof(width)];
-		CGFloat height = size.height;
-		NSData *heightData = [NSData dataWithBytes:&height
-						    length:sizeof(height)];
 		NSData *timestampData = [NSData
 			dataWithBytes:&timestamp
 			       length:sizeof(timestamp)];
@@ -148,19 +147,20 @@
 			dataWithBytes:&fpsDenominator
 			       length:sizeof(fpsDenominator)];
 
-		// NOTE: I'm not totally sure about the safety of dataWithBytesNoCopy in this context.
-		// Seems like there could potentially be an issue if the frameBuffer went away before the
-		// mach message finished sending. But it seems to be working and avoids a memory copy. Alternately
-		// we could do something like
-		// NSData *frameData = [NSData dataWithBytes:(void *)frameBytes length:size.width * size.height * 2];
-		NSData *frameData = [NSData
-			dataWithBytesNoCopy:(void *)frameBytes
-				     length:size.width * size.height * 2
-			       freeWhenDone:NO];
+		NSPort *framePort = [NSMachPort
+			portWithMachPort:IOSurfaceCreateMachPort(
+						 CVPixelBufferGetIOSurface(
+							 frame))];
+
+		if (!framePort) {
+			blog(LOG_ERROR,
+			     "unable to allocate mach port for pixel buffer");
+			return;
+		}
+
 		[self sendMessageToClientsWithMsgId:MachMsgIdFrame
 					 components:@[
-						 widthData, heightData,
-						 timestampData, frameData,
+						 framePort, timestampData,
 						 fpsNumeratorData,
 						 fpsDenominatorData
 					 ]];

plugins/mac-virtualcam/src/obs-plugin/plugin-main.mm

@@ -1,5 +1,4 @@
 #include <obs-module.h>
-#include <AppKit/AppKit.h>
 #include "OBSDALMachServer.h"
 #include "Defines.h"
 
@@ -10,9 +9,12 @@ MODULE_EXPORT const char *obs_module_description(void)
 	return "macOS virtual webcam output";
 }
 
-obs_output_t *outputRef;
-obs_video_info videoInfo;
-static OBSDALMachServer *sMachServer;
+struct virtualcam_data {
+	obs_output_t *output;
+	obs_video_info videoInfo;
+	CVPixelBufferPoolRef pool;
+	OBSDALMachServer *machServer;
+};
 
 static bool check_dal_plugin()
 {
@@ -105,37 +107,52 @@ static bool check_dal_plugin()
 	return true;
 }
 
+FourCharCode convert_video_format_to_mac(enum video_format format)
+{
+	switch (format) {
+	case VIDEO_FORMAT_I420:
+		return kCVPixelFormatType_420YpCbCr8Planar;
+	case VIDEO_FORMAT_NV12:
+		return kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
+	case VIDEO_FORMAT_UYVY:
+		return kCVPixelFormatType_422YpCbCr8;
+	default:
+		// Zero indicates that the format is not supported on macOS
+		// Note that some formats do have an associated constant, but
+		// constructing such formats fails with kCVReturnInvalidPixelFormat.
+		return 0;
+	}
+}
+
 static const char *virtualcam_output_get_name(void *type_data)
 {
 	(void)type_data;
 	return obs_module_text("Plugin_Name");
 }
 
-// This is a dummy pointer so we have something to return from virtualcam_output_create
-static void *data = &data;
-
 static void *virtualcam_output_create(obs_data_t *settings,
 				      obs_output_t *output)
 {
 	UNUSED_PARAMETER(settings);
 
-	outputRef = output;
+	struct virtualcam_data *vcam =
+		(struct virtualcam_data *)bzalloc(sizeof(*vcam));
 
-	blog(LOG_DEBUG, "output_create");
-	sMachServer = [[OBSDALMachServer alloc] init];
-	return data;
+	vcam->output = output;
+	vcam->machServer = [[OBSDALMachServer alloc] init];
+	return vcam;
 }
 
 static void virtualcam_output_destroy(void *data)
 {
-	UNUSED_PARAMETER(data);
-	blog(LOG_DEBUG, "output_destroy");
-	sMachServer = nil;
+	struct virtualcam_data *vcam = (struct virtualcam_data *)data;
+
+	vcam->machServer = nil;
 }
 
 static bool virtualcam_output_start(void *data)
 {
-	UNUSED_PARAMETER(data);
+	struct virtualcam_data *vcam = (struct virtualcam_data *)data;
 
 	bool hasDalPlugin = check_dal_plugin();
 
@@ -143,18 +160,45 @@ static bool virtualcam_output_start(void *data)
 		return false;
 	}
 
-	blog(LOG_DEBUG, "output_start");
+	obs_get_video_info(&vcam->videoInfo);
 
-	[sMachServer run];
+	FourCharCode video_format =
+		convert_video_format_to_mac(vcam->videoInfo.output_format);
 
-	obs_get_video_info(&videoInfo);
+	if (!video_format) {
+		// Selected output format is not supported natively by CoreVideo, CPU conversion necessary
+		blog(LOG_WARNING,
+		     "Selected output format (%s) not supported by CoreVideo, enabling CPU transcoding...",
+		     get_video_format_name(vcam->videoInfo.output_format));
 
-	struct video_scale_info conversion = {};
-	conversion.format = VIDEO_FORMAT_UYVY;
-	conversion.width = videoInfo.output_width;
-	conversion.height = videoInfo.output_height;
-	obs_output_set_video_conversion(outputRef, &conversion);
-	if (!obs_output_begin_data_capture(outputRef, 0)) {
+		struct video_scale_info conversion = {};
+		conversion.format = VIDEO_FORMAT_NV12;
+		conversion.width = vcam->videoInfo.output_width;
+		conversion.height = vcam->videoInfo.output_height;
+		obs_output_set_video_conversion(vcam->output, &conversion);
+
+		video_format = convert_video_format_to_mac(conversion.format);
+	}
+
+	NSDictionary *pAttr = @{};
+	NSDictionary *pbAttr = @{
+		(id)kCVPixelBufferPixelFormatTypeKey: @(video_format),
+		(id)kCVPixelBufferWidthKey: @(vcam->videoInfo.output_width),
+		(id)kCVPixelBufferHeightKey: @(vcam->videoInfo.output_height),
+		(id)kCVPixelBufferIOSurfacePropertiesKey: @{}
+	};
+	CVReturn status = CVPixelBufferPoolCreate(
+		kCFAllocatorDefault, (__bridge CFDictionaryRef)pAttr,
+		(__bridge CFDictionaryRef)pbAttr, &vcam->pool);
+	if (status != kCVReturnSuccess) {
+		blog(LOG_ERROR,
+		     "unable to allocate pixel buffer pool (error %d)", status);
+		return false;
+	}
+
+	[vcam->machServer run];
+
+	if (!obs_output_begin_data_capture(vcam->output, 0)) {
 		return false;
 	}
 
@@ -163,33 +207,97 @@ static bool virtualcam_output_start(void *data)
 
 static void virtualcam_output_stop(void *data, uint64_t ts)
 {
-	UNUSED_PARAMETER(data);
 	UNUSED_PARAMETER(ts);
 
-	blog(LOG_DEBUG, "output_stop");
-	obs_output_end_data_capture(outputRef);
-	[sMachServer stop];
+	struct virtualcam_data *vcam = (struct virtualcam_data *)data;
+
+	obs_output_end_data_capture(vcam->output);
+	[vcam->machServer stop];
+
+	CVPixelBufferPoolRelease(vcam->pool);
 }
 
 static void virtualcam_output_raw_video(void *data, struct video_data *frame)
 {
-	UNUSED_PARAMETER(data);
+	struct virtualcam_data *vcam = (struct virtualcam_data *)data;
 
-	uint8_t *outData = frame->data[0];
-	if (frame->linesize[0] != (videoInfo.output_width * 2)) {
-		blog(LOG_ERROR,
-		     "unexpected frame->linesize (expected:%d actual:%d)",
-		     (videoInfo.output_width * 2), frame->linesize[0]);
+	CVPixelBufferRef frameRef = nil;
+	CVReturn status = CVPixelBufferPoolCreatePixelBuffer(
+		kCFAllocatorDefault, vcam->pool, &frameRef);
+
+	if (status != kCVReturnSuccess) {
+		blog(LOG_ERROR, "unable to allocate pixel buffer (error %d)",
+		     status);
+		return;
 	}
 
-	CGFloat width = videoInfo.output_width;
-	CGFloat height = videoInfo.output_height;
+	// Copy all planes into pixel buffer
+	size_t planeCount = CVPixelBufferGetPlaneCount(frameRef);
+	CVPixelBufferLockBaseAddress(frameRef, 0);
 
-	[sMachServer sendFrameWithSize:NSMakeSize(width, height)
-			     timestamp:frame->timestamp
-			  fpsNumerator:videoInfo.fps_num
-			fpsDenominator:videoInfo.fps_den
-			    frameBytes:outData];
+	if (planeCount == 0) {
+		uint8_t *src = frame->data[0];
+		uint8_t *dst = (uint8_t *)CVPixelBufferGetBaseAddress(frameRef);
+
+		size_t destBytesPerRow = CVPixelBufferGetBytesPerRow(frameRef);
+		size_t srcBytesPerRow = frame->linesize[0];
+		size_t height = CVPixelBufferGetHeight(frameRef);
+
+		// Sometimes CVPixelBufferCreate will create a pixel buffer that's a different
+		// size than necessary to hold the frame (probably for some optimization reason).
+		// If that is the case this will do a row-by-row copy into the buffer.
+		if (destBytesPerRow == srcBytesPerRow) {
+			memcpy(dst, src, destBytesPerRow * height);
+		} else {
+			for (int line = 0; (size_t)line < height; line++) {
+				memcpy(dst, src, srcBytesPerRow);
+				src += srcBytesPerRow;
+				dst += destBytesPerRow;
+			}
+		}
+	} else {
+		for (size_t plane = 0; plane < planeCount; plane++) {
+			uint8_t *src = frame->data[plane];
+
+			if (!src) {
+				blog(LOG_WARNING,
+				     "Video data from OBS contains less planes than CVPixelBuffer");
+				break;
+			}
+
+			uint8_t *dst =
+				(uint8_t *)CVPixelBufferGetBaseAddressOfPlane(
+					frameRef, plane);
+
+			size_t destBytesPerRow =
+				CVPixelBufferGetBytesPerRowOfPlane(frameRef,
+								   plane);
+			size_t srcBytesPerRow = frame->linesize[plane];
+			size_t height =
+				CVPixelBufferGetHeightOfPlane(frameRef, plane);
+
+			if (destBytesPerRow == srcBytesPerRow) {
+				memcpy(dst, src, destBytesPerRow * height);
+			} else {
+				for (int line = 0; (size_t)line < height;
+				     line++) {
+					memcpy(dst, src, srcBytesPerRow);
+					src += srcBytesPerRow;
+					dst += destBytesPerRow;
+				}
+			}
+		}
+	}
+
+	CVPixelBufferUnlockBaseAddress(frameRef, 0);
+
+	// Share pixel buffer with clients
+	[vcam->machServer sendPixelBuffer:frameRef
+				timestamp:frame->timestamp
+			     fpsNumerator:vcam->videoInfo.fps_num
+			   fpsDenominator:vcam->videoInfo.fps_den];
+
+	CVPixelBufferRelease(frameRef);
 }
 
 struct obs_output_info virtualcam_output_info = {