everyone! The idea in my project is to gather a video, split it into frames, then apply specific effect frame by frame(not the topic) and then compile everything back.
Using following code I am able to read the video into frames and pass them into array:
//initialize avassetreader
AVAsset *avAsset = [AVAsset assetWithURL:url];
NSError *error = nil;
AVAssetReader *reader = [[AVAssetReader alloc] initWithAsset:avAsset error:&error];
//get video track
NSArray *videoTracks = [avAsset tracksWithMediaType:AVMediaTypeVideo];
AVAssetTrack *videoTrack = [videoTracks objectAtIndex:0];
NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
AVAssetReaderTrackOutput *asset_reader_output = [[AVAssetReaderTrackOutput alloc] initWithTrack:videoTrack outputSettings:options];
[reader addOutput:asset_reader_output];
[reader startReading];
Next, as I said above I read the track frame by frame
//while there is something to read
while ( [reader status]==AVAssetReaderStatusReading ) {
CMSampleBufferRef sampleBuffer = [asset_reader_output copyNextSampleBuffer];
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
// Lock the base address of the pixel buffer
CVPixelBufferLockBaseAddress(imageBuffer, 0);
// Get the number of bytes per row for the pixel buffer
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
// Get the pixel buffer width and height
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);
//Generate image to edit
unsigned char* pixel = (unsigned char *)CVPixelBufferGetBaseAddress(imageBuffer);
CGColorSpaceRef colorSpace=CGColorSpaceCreateDeviceRGB();
CGContextRef context=CGBitmapContextCreate(pixel, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little|kCGImageAlphaPremultipliedFirst);
CGImageRef image = CGBitmapContextCreateImage(context);
UIImage* myImage = [[UIImage alloc] initWithCGImage:image];
[photos addObject:myImage];
}
I am able to put everything into an array but I need to compile everything back into a video track, compile it with audio from original track an then save. However, I couldn't find any useful information on the web. Please, help!
Thanks in advance!
