• CVPixelBuffer


    https://www.cnblogs.com/psklf/p/7700834.html

    https://stackoverflow.com/questions/16475737/convert-uiimage-to-cmsamplebufferref

    - (CGImageRef) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer // Create a CGImageRef from sample buffer data
    {
        CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
        CVPixelBufferLockBaseAddress(imageBuffer,0);        // Lock the image buffer
    
        uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);   // Get information of the image
        size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
        size_t width = CVPixelBufferGetWidth(imageBuffer);
        size_t height = CVPixelBufferGetHeight(imageBuffer);
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    
        CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
        CGImageRef newImage = CGBitmapContextCreateImage(newContext);
        CGContextRelease(newContext);
    
        CGColorSpaceRelease(colorSpace);
        CVPixelBufferUnlockBaseAddress(imageBuffer,0);
        /* CVBufferRelease(imageBuffer); */  // do not call this!
    
        return newImage;
    }
    //This is a function that I use in my GPUImage framework to resize an incoming CMSampleBufferRef and place the scaled results within a CVPixelBufferRef that you provide:
    
    void GPUImageCreateResizedSampleBuffer(CVPixelBufferRef cameraFrame, CGSize finalSize, CMSampleBufferRef *sampleBuffer)
    {
        // CVPixelBufferCreateWithPlanarBytes for YUV input
    
        CGSize originalSize = CGSizeMake(CVPixelBufferGetWidth(cameraFrame), CVPixelBufferGetHeight(cameraFrame));
    
        CVPixelBufferLockBaseAddress(cameraFrame, 0);
        GLubyte *sourceImageBytes =  CVPixelBufferGetBaseAddress(cameraFrame);
        CGDataProviderRef dataProvider = CGDataProviderCreateWithData(NULL, sourceImageBytes, CVPixelBufferGetBytesPerRow(cameraFrame) * originalSize.height, NULL);
        CGColorSpaceRef genericRGBColorspace = CGColorSpaceCreateDeviceRGB();
        CGImageRef cgImageFromBytes = CGImageCreate((int)originalSize.width, (int)originalSize.height, 8, 32, CVPixelBufferGetBytesPerRow(cameraFrame), genericRGBColorspace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst, dataProvider, NULL, NO, kCGRenderingIntentDefault);
    
        GLubyte *imageData = (GLubyte *) calloc(1, (int)finalSize.width * (int)finalSize.height * 4);
    
        CGContextRef imageContext = CGBitmapContextCreate(imageData, (int)finalSize.width, (int)finalSize.height, 8, (int)finalSize.width * 4, genericRGBColorspace,  kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
        CGContextDrawImage(imageContext, CGRectMake(0.0, 0.0, finalSize.width, finalSize.height), cgImageFromBytes);
        CGImageRelease(cgImageFromBytes);
        CGContextRelease(imageContext);
        CGColorSpaceRelease(genericRGBColorspace);
        CGDataProviderRelease(dataProvider);
    
        CVPixelBufferRef pixel_buffer = NULL;
        CVPixelBufferCreateWithBytes(kCFAllocatorDefault, finalSize.width, finalSize.height, kCVPixelFormatType_32BGRA, imageData, finalSize.width * 4, stillImageDataReleaseCallback, NULL, NULL, &pixel_buffer);
        CMVideoFormatDescriptionRef videoInfo = NULL;
        CMVideoFormatDescriptionCreateForImageBuffer(NULL, pixel_buffer, &videoInfo);
    
        CMTime frameTime = CMTimeMake(1, 30);
        CMSampleTimingInfo timing = {frameTime, frameTime, kCMTimeInvalid};
    
        CMSampleBufferCreateForImageBuffer(kCFAllocatorDefault, pixel_buffer, YES, NULL, NULL, videoInfo, &timing, sampleBuffer);
        CFRelease(videoInfo);
        CVPixelBufferRelease(pixel_buffer);
    }
    //It doesn't take you all the way to creating a CMSampleBufferRef, but as weichsel points out, you only need the CVPixelBufferRef for encoding the video.
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  • 原文地址:https://www.cnblogs.com/yuxiaoyiyou/p/9087743.html
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