I have the following test code which is supposed to create a video file of a image file in OSX. However altho running successfully the video file is unplayable....
Can anyone think of what i might of done wrong or missed?
- (void)testVideoWriter { NSImage *someImage = [NSImage imageNamed:@"002"]; CGSize size = CGSizeMake(someImage.size.width, someImage.size.height); CMTime frameLength = CMTimeMake(1, 5); CMTime currentTime = kCMTimeZero; NSError *error = nil; //remember to delete video before re-runnign or you will get fails... AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:[NSURL fileURLWithPath:@"/Users/petertribe/Desktop/testvideo.mov"] fileType:AVFileTypeMPEG4 error:&error]; NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:AVVideoCodecH264, AVVideoCodecKey, [NSNumber numberWithInt:size.width ], AVVideoWidthKey, [NSNumber numberWithInt:size.height ], AVVideoHeightKey, nil]; AVAssetWriterInput *writerInput = [AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings]; NSDictionary *sourcePixelBufferAttributesDictionary = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:k32ARGBPixelFormat], kCVPixelBufferPixelFormatTypeKey, nil]; AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput sourcePixelBufferAttributes:sourcePixelBufferAttributesDictionary]; [videoWriter addInput:writerInput]; [videoWriter startWriting]; [videoWriter startSessionAtSourceTime:kCMTimeZero]; for (int i = 0; i < 100; i++) { CVPixelBufferRef pixel_buffer = [self fastImageFromNSImage:someImage]; while (adaptor.assetWriterInput.readyForMoreMediaData == FALSE) { NSDate *maxDate = [NSDate dateWithTimeIntervalSinceNow:0.1]; [[NSRunLoop currentRunLoop] runUntilDate:maxDate]; } if(![adaptor appendPixelBuffer:pixel_buffer withPresentationTime:currentTime]) { NSLog(@"FAIL"); } else { NSLog(@"Success:%d", i); currentTime = CMTimeAdd(currentTime, frameLength); } CVPixelBufferRelease(pixel_buffer); } [writerInput markAsFinished]; NSLog(@"Done"); } - (CVPixelBufferRef)fastImageFromNSImage:(NSImage *)image { CVPixelBufferRef buffer = NULL; // config size_t width = [image size].width; size_t height = [image size].height; size_t bitsPerComponent = 8; CGColorSpaceRef cs = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB); CGBitmapInfo bi = kCGImageAlphaNoneSkipFirst; NSDictionary *d = [NSDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey, [NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey, nil]; // create pixel buffer CVPixelBufferCreate(kCFAllocatorDefault, width, height, k32ARGBPixelFormat, (__bridge CFDictionaryRef)d, &buffer); CVPixelBufferLockBaseAddress(buffer, 0); void *rasterData = CVPixelBufferGetBaseAddress(buffer); size_t bytesPerRow = CVPixelBufferGetBytesPerRow(buffer); // context to draw in, set to pixel buffer's address CGContextRef ctxt = CGBitmapContextCreate(rasterData, width, height, bitsPerComponent, bytesPerRow, cs, bi); if(ctxt == NULL){ NSLog(@"could not create context"); return NULL; } // draw NSGraphicsContext *nsctxt = [NSGraphicsContext graphicsContextWithGraphicsPort:ctxt flipped:NO]; [NSGraphicsContext saveGraphicsState]; [NSGraphicsContext setCurrentContext:nsctxt]; [image drawAtPoint:NSMakePoint(0, 0) fromRect:NSMakeRect(0, 0, image.size.width, image.size.height) operation:NSCompositeCopy fraction:1]; [NSGraphicsContext restoreGraphicsState]; CVPixelBufferUnlockBaseAddress(buffer, 0); CFRelease(ctxt); return buffer; } 
