AVFoundation: add text to the CMSampleBufferRef video frame

Question

I\'m building an app using AVFoundation.

Just before I call [assetWriterInput appendSampleBuffer:sampleBuffer] in - (void)captureOutput:(AVCaptureOutp

Answer 1

You should refer the CIFunHouse sample from apple, and you may use this api to draw directly to the buffer

-(void)render:(CIImage *)image toCVPixelBuffer:(CVPixelBufferRef)buffer bounds:(CGRect)r colorSpace:(CGColorSpaceRef)cs

You can download it here WWDC2013

Create the context

_eaglContext = [[EAGLContext alloc] initWithAPI:kEAGLRenderingAPIOpenGLES2];
_ciContext = [CIContext contextWithEAGLContext:_eaglContext options:@{kCIContextWorkingColorSpace : [NSNull null]} ];

Now render the image

CVPixelBufferRef renderedOutputPixelBuffer = NULL;
OSStatus err = CVPixelBufferPoolCreatePixelBuffer(nil, self.pixelBufferAdaptor.pixelBufferPool, &renderedOutputPixelBuffer);
[_ciContext render:filteredImage toCVPixelBuffer:renderedOutputPixelBuffer bounds:[filteredImage extent]