第43月第11天 kCVPixelFormatType_420YpCbCr8BiPlanarFullRange转rgb

1.

#define clamp(a) (a>255?255:(a<0?0:a))

- (UIImage *)imageFromSampleBuffer:(CMSampleBufferRef)sampleBuffer {
    CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
    CVPixelBufferLockBaseAddress(imageBuffer,0);

    size_t width = CVPixelBufferGetWidth(imageBuffer);
    size_t height = CVPixelBufferGetHeight(imageBuffer);
    uint8_t *yBuffer = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);
    size_t yPitch = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 0);
    uint8_t *cbCrBuffer = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 1);
    size_t cbCrPitch = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer, 1);

    int bytesPerPixel = 4;
    uint8_t *rgbBuffer = malloc(width * height * bytesPerPixel);

    for(int y = 0; y < height; y++) {
        uint8_t *rgbBufferLine = &rgbBuffer[y * width * bytesPerPixel];
        uint8_t *yBufferLine = &yBuffer[y * yPitch];
        uint8_t *cbCrBufferLine = &cbCrBuffer[(y >> 1) * cbCrPitch];

        for(int x = 0; x < width; x++) {
            int16_t y = yBufferLine[x];
            int16_t cb = cbCrBufferLine[x & ~1] - 128;
            int16_t cr = cbCrBufferLine[x | 1] - 128;

            uint8_t *rgbOutput = &rgbBufferLine[x*bytesPerPixel];

            int16_t r = (int16_t)roundf( y + cr *  1.4 );
            int16_t g = (int16_t)roundf( y + cb * -0.343 + cr * -0.711 );
            int16_t b = (int16_t)roundf( y + cb *  1.765);

            rgbOutput[0] = 0xff;
            rgbOutput[1] = clamp(b);
            rgbOutput[2] = clamp(g);
            rgbOutput[3] = clamp(r);
        }
    }

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbBuffer, width, height, 8, width * bytesPerPixel, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    CGImageRef quartzImage = CGBitmapContextCreateImage(context);
    UIImage *image = [UIImage imageWithCGImage:quartzImage];

    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    CGImageRelease(quartzImage);
    free(rgbBuffer);

    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

    return image;
}

https://stackoverflow.com/questions/8838481/kcvpixelformattype-420ypcbcr8biplanarfullrange-frame-to-uiimage-conversion

2.rgb写文件

ffplay -s 720x405 -pix_fmt rgb32  0.rgb

- (void)dealWithSampleBuffer:(CMSampleBufferRef)buffer {

    CVPixelBufferRef pixelBuffer = CMSampleBufferGetImageBuffer(buffer);
    CIImage *ciimage = [CIImage imageWithCVPixelBuffer:pixelBuffer];
    size_t width = CVPixelBufferGetWidth(pixelBuffer);
    size_t height = CVPixelBufferGetHeight(pixelBuffer);

    NSLog(@"pixelBuffer %d height:%d",width,height);
    
    CGFloat widthScale = width/720.0;
    CGFloat heightScale = height/1280.0;
    CGFloat realWidthScale = 1;
    CGFloat realHeightScale = 1;
    
    if (widthScale > 1 || heightScale > 1) {
        if (widthScale < heightScale) {
            realHeightScale = 1280.0/height;
            CGFloat nowWidth = width * 1280 / height;
            height = 1280;
            realWidthScale = nowWidth/width;
            width = nowWidth;
        } else {
            realWidthScale = 720.0/width;
            CGFloat nowHeight = 720 * height / width;
            width = 720;
            realHeightScale = nowHeight/height;
            height = nowHeight;
        }
    }
    
    
    {
        _ciContext = [CIContext contextWithOptions:nil];
        
        CIImage *newImage = [ciimage imageByApplyingTransform:CGAffineTransformMakeScale(realWidthScale, realHeightScale)];
//        UIImage *tmpImage = [self imageWithColor:[UIColor redColor] AndRect:CGRectMake(0, 0, width, height)];
//        CIImage *newImage = [CIImage imageWithCGImage:tmpImage.CGImage];
        
        CVPixelBufferLockBaseAddress(pixelBuffer, 0);
        CVPixelBufferRef newPixcelBuffer = nil;
        CVPixelBufferCreate(kCFAllocatorDefault, width, height, kCVPixelFormatType_32BGRA, nil, &newPixcelBuffer);
        [_ciContext render:newImage toCVPixelBuffer:newPixcelBuffer];
        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
//        [self.videoEncoder encodeVideoData:newPixcelBuffer timeStamp:(CACurrentMediaTime()*1000)];
        
        size_t newWidth = CVPixelBufferGetWidth(newPixcelBuffer);
        size_t newHeight = CVPixelBufferGetHeight(newPixcelBuffer);
        NSLog(@"newPixcelBuffer %d height:%d",newWidth,newHeight);
        
        UIImage* sampleImage = [self imageFromSamplePlanerPixelBuffer:newPixcelBuffer];
        
        CVPixelBufferRelease(newPixcelBuffer);
    }
}

- (UIImage *)imageWithColor:(UIColor *)color AndRect:(CGRect)rect{

    UIGraphicsBeginImageContext(rect.size);

    CGContextRef context = UIGraphicsGetCurrentContext();

    

    CGContextSetFillColorWithColor(context, [color CGColor]);

    CGContextFillRect(context, rect);

    

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    

    return image;

}

- (UIImage *) imageFromSamplePlanerPixelBuffer:(CVPixelBufferRef)imageBuffer{
    @autoreleasepool {
//        // Get a CMSampleBuffer's Core Video image buffer for the media data
//        CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
        // Lock the base address of the pixel buffer
        CVPixelBufferLockBaseAddress(imageBuffer, 0);
        
        // Get the number of bytes per row for the plane pixel buffer
        void *baseAddress = CVPixelBufferGetBaseAddressOfPlane(imageBuffer, 0);
        
        // Get the number of bytes per row for the plane pixel buffer
        size_t bytesPerRow = CVPixelBufferGetBytesPerRowOfPlane(imageBuffer,0);
        // Get the pixel buffer width and height
        size_t width = CVPixelBufferGetWidth(imageBuffer);
        size_t height = CVPixelBufferGetHeight(imageBuffer);
        

        size_t size = CVPixelBufferGetDataSize(imageBuffer);

        OSType type = CVPixelBufferGetPixelFormatType(imageBuffer);
        
        NSLog(@"buffer type:%d size:%d",type,size);
        
        static int i=0;
        i++;
        if (i<4) {
            


            int len = (int)width * height *4;
            uint8_t *rgb_frame = (uint8_t *)malloc(len);
            
            for(int y = 0; y < height; y++) {
                 uint8_t *yBufferLine = &baseAddress[y * bytesPerRow];
                for(int x = 0; x < bytesPerRow; x++) {
                
                    rgb_frame[x+y * bytesPerRow] = yBufferLine[x];
                }
            }
            
            NSString *path2 = [self getHome2Path];
            const char *resultCString2 = NULL;
            if ([path2 canBeConvertedToEncoding:NSUTF8StringEncoding]) {
                resultCString2 = [path2 cStringUsingEncoding:NSUTF8StringEncoding];
            }
            
            unsigned char *buffer = (unsigned char *)rgb_frame;

            FILE* fpyuv = fopen(resultCString2, "wb");
            for (int i = 0; i < len; i ++) {
                fwrite(buffer, 1, 1, fpyuv);
                buffer ++;
            }
            fclose(fpyuv);
            
            free(rgb_frame);
        }
        
        
        // Create a device-dependent RGB color space
        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        
        // Create a bitmap graphics context with the sample buffer data
        CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8,
                                                     bytesPerRow, colorSpace, kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little);
        // Create a Quartz image from the pixel data in the bitmap graphics context
        CGImageRef quartzImage = CGBitmapContextCreateImage(context);
        // Unlock the pixel buffer
        CVPixelBufferUnlockBaseAddress(imageBuffer,0);
        
        // Free up the context and color space
        CGContextRelease(context);
        CGColorSpaceRelease(colorSpace);
        
        // Create an image object from the Quartz image
        UIImage *image = [UIImage imageWithCGImage:quartzImage];
        
        // Release the Quartz image
        CGImageRelease(quartzImage);
        return (image);
    }
}