AVAssetWriter giving bluish video file

Question

I am recoding a video from my app's screen using the AVAssetWriter class. Video records. but the recoded video is bluish one. my code to set up the AVAssetWriter is below

-(BOOL) setUpWriter {
    NSError* error = nil;
    videoWriter = [[AVAssetWriter alloc] initWithURL:[self tempFileURL] fileType:AVFileTypeAppleM4V error:&error];
    NSParameterAssert(videoWriter);

    //Configure video
    NSDictionary* videoCompressionProps = [NSDictionary dictionaryWithObjectsAndKeys:
                                           [NSNumber numberWithDouble:1024.0*1024.0], AVVideoAverageBitRateKey,
                                           nil ];

    CGSize size=[CCDirector sharedDirector].winSize;
    NSDictionary* videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
                                   AVVideoCodecH264, AVVideoCodecKey,
                                   [NSNumber numberWithInt:size.width], AVVideoWidthKey,
                                   [NSNumber numberWithInt:size.height], AVVideoHeightKey,
                                   videoCompressionProps, AVVideoCompressionPropertiesKey,
                                   nil];

    videoWriterInput = [[AVAssetWriterInput assetWriterInputWithMediaType:AVMediaTypeVideo outputSettings:videoSettings] retain];

    NSParameterAssert(videoWriterInput);
    videoWriterInput.expectsMediaDataInRealTime = YES;
    NSDictionary* bufferAttributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                      [NSNumber numberWithInt:kCVPixelFormatType_32ARGB], kCVPixelBufferPixelFormatTypeKey, nil];

    avAdaptor = [[AVAssetWriterInputPixelBufferAdaptor assetWriterInputPixelBufferAdaptorWithAssetWriterInput:videoWriterInput sourcePixelBufferAttributes:bufferAttributes] retain];

    //add input
    [videoWriter addInput:videoWriterInput];
    [videoWriter startWriting];
    [videoWriter startSessionAtSourceTime:CMTimeMake(0, 1000)];

    return YES;
}

Is there any bugs in my code. How can I solve this problem

Answer 1

Your AVAssetWriterInput is expecting ARGB but you're probably supplying it with RGBA.

That would see the probable 100% alpha interpreted as blue and the red component discarded, which would explain your bluish tint.

Hard to tell without seeing your screen recording code.