Question

How can I make the process that filtering saved video in photo library in iOS?

I got URLs of videos in the library using AssetsLibrary framework,

then, made a preview for the video.

Next step, I wanna make filtering process for video using CIFilter.

In case of real time issue, I made video filter process using AVCaptureVideoDataOutputSampleBufferDelegate.

But in case of saved video, I don’t know how to make filter process.

Do I use AVAsset? If I must use that, how can I filter it? and how to save it?

always thank you.

Answer 1

I hope this will help you

 AVAsset *theAVAsset = [[AVURLAsset alloc] initWithURL:mNormalVideoURL options:nil];
       NSError *error = nil;
        float width = theAVAsset.naturalSize.width;
        float height = theAVAsset.naturalSize.height; 
        AVAssetReader *mAssetReader = [[AVAssetReader alloc] initWithAsset:theAVAsset error:&error]; 
        [theAVAsset release];




    NSArray *videoTracks = [theAVAsset tracksWithMediaType:AVMediaTypeVideo]; 
    AVAssetTrack *videoTrack = [videoTracks objectAtIndex:0];
    mPrefferdTransform = [videoTrack preferredTransform];


    NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey:(id)kCVPixelBufferPixelFormatTypeKey];
   AVAssetReaderTrackOutput* mAssetReaderOutput = [[AVAssetReaderTrackOutput alloc] initWithTrack:videoTrack outputSettings:options];

    [mAssetReader addOutput:mAssetReaderOutput];
    [mAssetReaderOutput release];


    CMSampleBufferRef buffer = NULL;
    //CMSampleBufferRef buffer = NULL;
    while ( [mAssetReader status]==AVAssetReaderStatusReading ){
            buffer = [mAssetReaderOutput copyNextSampleBuffer];//read next image.
}