I have code that has worked for many years for writing ProRes files, and it is now failing on the new M1 Max MacBook. Specifically, if I construct buffers with the pixel type "kCVPixelFormatType_64ARGB", after a few frames of writing, the pixel buffer pool becomes nil. This code works just fine on non Max processors (Intel and base M1 natively).
Here's a sample main that demonstrates the problem. Am I doing something wrong here?
// main.m
// TestProresWriting
//
#import <Foundation/Foundation.h>
#import <AVFoundation/AVFoundation.h>
int main(int argc, const char * argv[]) {
@autoreleasepool {
int timescale = 24;
int width = 1920;
int height = 1080;
NSURL *url = [NSURL URLWithString:@"file:///Users/diftil/TempData/testfile.mov"];
NSLog(@"Output file = %@", [url absoluteURL]);
NSFileManager *fileManager = [NSFileManager defaultManager];
NSError *error = nil;
[fileManager removeItemAtURL:url error:&error];
// Set up the writer
AVAssetWriter *trackWriter = [[AVAssetWriter alloc] initWithURL:url
fileType:AVFileTypeQuickTimeMovie
error:&error];
// Set up the track
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecTypeAppleProRes4444, AVVideoCodecKey,
[NSNumber numberWithInt:width], AVVideoWidthKey,
[NSNumber numberWithInt:height], AVVideoHeightKey,
nil];
AVAssetWriterInput *track = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings];
// Set up the adapter
NSDictionary *attributes = [NSDictionary
dictionaryWithObjects:
[NSArray arrayWithObjects:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_64ARGB], // This pixel type causes problems on M1 Max, but works on everything else
[NSNumber numberWithUnsignedInt:width],[NSNumber numberWithUnsignedInt:height],
nil]
forKeys:
[NSArray arrayWithObjects:(NSString *)kCVPixelBufferPixelFormatTypeKey,
(NSString*)kCVPixelBufferWidthKey, (NSString*)kCVPixelBufferHeightKey,
nil]];
/*
NSDictionary *attributes = [NSDictionary
dictionaryWithObjects:
[NSArray arrayWithObjects:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB], // This pixel type works on M1 Max
[NSNumber numberWithUnsignedInt:width],[NSNumber numberWithUnsignedInt:height],
nil]
forKeys:
[NSArray arrayWithObjects:(NSString *)kCVPixelBufferPixelFormatTypeKey,
(NSString*)kCVPixelBufferWidthKey, (NSString*)kCVPixelBufferHeightKey,
nil]];
*/
AVAssetWriterInputPixelBufferAdaptor *pixelBufferAdaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:track
sourcePixelBufferAttributes:attributes];
// Add the track and start writing
[trackWriter addInput:track];
[trackWriter startWriting];
CMTime startTime = CMTimeMake(0, timescale);
[trackWriter startSessionAtSourceTime:startTime];
while(!track.readyForMoreMediaData);
int frameTime = 0;
CVPixelBufferRef frameBuffer = NULL;
for (int i = 0; i < 100; i++)
{
NSLog(@"Frame %@", [NSString stringWithFormat:@"%d", i]);
CVPixelBufferPoolRef PixelBufferPool = pixelBufferAdaptor.pixelBufferPool;
if (PixelBufferPool == nil)
{
NSLog(@"PixelBufferPool is invalid.");
exit(1);
}
CVReturn ret = CVPixelBufferPoolCreatePixelBuffer(nil, PixelBufferPool, &frameBuffer);
if (ret != kCVReturnSuccess)
{
NSLog(@"Error creating framebuffer from pool");
exit(1);
}
CVPixelBufferLockBaseAddress(frameBuffer, 0);
// This is where we would put image data into the buffer. Nothing right now.
CVPixelBufferUnlockBaseAddress(frameBuffer, 0);
while(!track.readyForMoreMediaData);
CMTime presentationTime = CMTimeMake(frameTime+(i*timescale), timescale);
BOOL result = [pixelBufferAdaptor appendPixelBuffer:frameBuffer
withPresentationTime:presentationTime];
if (result == NO)
{
NSLog(@"Error appending to track.");
exit(1);
}
CVPixelBufferRelease(frameBuffer);
}
// Close everything
if ( trackWriter.status == AVAssetWriterStatusWriting)
[track markAsFinished];
NSLog(@"Completed.");
}
return 0;
}
