Hi,
I'm trying to create a Movie via ICMCompressionSession. The input comes from an QTCaptureSession via the QTCaptureDecompressedVideoOutput. I started to feed the frame over the didOutputVideiFrame is works fine:
- (void)captureOutput:(QTCaptureOutput *)captureOutput didOutputVideoFrame:(CVImageBufferRef)videoFrame withSampleBuffer: (QTSampleBuffer *)sampleBuffer fromConnection:(QTCaptureConnection *)connection
{
err = ICMCompressionSessionEncodeFrame( mCompressionSession, videoFrame , timeStamp, [sampleBuffer duration].timeValue, kICMValidTime_DisplayTimeStampIsValid, NULL, NULL, NULL );
timeStamp = timeStamp + timescale;
}
so now I tried to modify the a CIImage that i get from videoFrame and write it into the ICMCompressionSession using an CVPixelBuffer. The pixelBuffer came from a ICMCompression-Pixelbufferpool. Now I have memory problems the app does alloc more and more memory, even if only pass an PixelBuffer directly from the pool like this:
CVImageBufferRef buffer;
theError = CVPixelBufferPoolCreatePixelBuffer(NULL, mBufferPool, &buffer);
if(theError)....
else{
CVPixelBufferRetain(buffer);
err = ICMCompressionSessionEncodeFrame( mCompressionSession, buffer , timeStamp, [sampleBuffer duration].timeValue, kICMValidTime_DisplayTimeStampIsValid, NULL, NULL, NULL );
timeStamp = timeStamp + timescale;
CVPixelBufferRelease(buffer);
}
Someday it should look like this:
CVImageBufferRef buffer;
theError = CVPixelBufferPoolCreatePixelBuffer(NULL, mBufferPool, &buffer);
if(theError)...
CVPixelBufferRetain(buffer);
theError = CVPixelBufferLockBaseAddress(buffer, 0);
if(theError)....
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
void * rasterData = CVPixelBufferGetBaseAddress(buffer);
CGContextRef cgContextRef = CGBitmapContextCreate( rasterData, CVPixelBufferGetWidth(buffer), CVPixelBufferGetHeight(buffer), 8, CVPixelBufferGetBytesPerRow(buffer), colorSpace, kCGImageAlphaPremultipliedLast);
if(cgContextRef == nil)...
CIContext * cicontext = [CIContext contextWithCGContext:cgContextRef options:nil];
CIImage* inputImage1 = [CIImage imageWithCVImageBuffer:videoFrame];
//do CIFilter stuff .....
CGImageRef cgImage = [cicontext createCGImage:inputImage1 fromRect:[inputImage1 extent]];
CGContextDrawImage(cgContextRef, [inputImage1 extent], cgImage);
err = ICMCompressionSessionEncodeFrame( mCompressionSession, buffer , timeStamp, [sampleBuffer duration].timeValue, kICMValidTime_DisplayTimeStampIsValid, NULL, NULL, NULL );
timeStamp = timeStamp +timescale;
if(err)...
CGColorSpaceRelease(colorSpace);
CGImageRelease(cgImage);
[cicontext release];
CGContextRelease(cgContextRef);
CVPixelBufferRelease(buffer);
So i must do something wrong:
- did I forget to register a Callback for clean up the buffer?
- do I have to copy the CVBufferAttachments from the videoframe to the buffer?
- do I have to call something for clean up?
- Not enough Performance? Is does no look like. i am working on an 8-Core MacPro and all CPU's are working between 50-60%.
Datails about the ICMCompressionSession:
- Codec: Appel Prores 422 HQ
- Format is Full HD 1920x1080
- Input via AJA Card
Thanks for help
Hannes Osius
