AVAssetWriter unknown error

Question

Am trying to create video from images using AVAssetWriter. Implemented code works fine most of time, but in random moments there is problem with writer

AVAssetWriter *videoWriter;
...
[videoWriter finishWriting];
NSLog(@"videoWriter error %@",videoWriter.error);

Received error is:

Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" 
UserInfo=0x1f839cd0 {NSLocalizedDescription=The operation could not be completed,
 NSUnderlyingError=0x1e59efb0 "The operation couldn’t be completed. (OSStatus error -12633.)", 
NSLocalizedFailureReason=An unknown error occurred (-12633)}

Writing images:

-(void)writeFrame:(WriteableFrame*)wF
{
    if([writerInput isReadyForMoreMediaData])
    {
        CMTime presentTime = CMTimeMake(wF.frameTime, 1000);
        CGImageRef tmpImgRef = [wF.currentImage CGImage];
        buffer = [self pixelBufferFromCGImage:tmpImgRef];
        if(buffer)
        {
            [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
            CVPixelBufferRelease(buffer);
        }
    }
    else
    {
        NSLog(@"error");
    }
}

Is there someone with problem like this?

Answer 1

I found the problem, it was putting two frames at the same frame time.