create rgb image from yuv color space

yuv2rgb.mm

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

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

    if (CVPixelBufferGetPlaneCount(imageBuffer) < 2) {
        CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
        return nil;
    }
    
    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);
        }
    }
    
    CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbBuffer, width, height, 8, width * bytesPerPixel, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    
    CGImageRef cgImage = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    free(rgbBuffer);
    
    UIImage *image = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return image;
}

yuv2rgb_webrtc.mm

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

+ (UIImage *)convert:(RTCVideoFrame *)frame {
    RTCI420Buffer *buffer = (RTCI420Buffer *)frame.buffer;
    
    int width = buffer.width;
    int height = buffer.height;
    int bytesPerPixel = 4;
    uint8_t *rgbBuffer = malloc(width * height * bytesPerPixel);
    
    for(int row = 0; row < height; row++) {
        const uint8_t *yLine = &buffer.dataY[row * buffer.strideY];
        const uint8_t *uLine = &buffer.dataU[(row >> 1) * buffer.strideU];
        const uint8_t *vLine = &buffer.dataV[(row >> 1) * buffer.strideV];
        
        for(int x = 0; x < width; x++) {
            int16_t y = yLine[x];
            int16_t u = uLine[x >> 1] - 128;
            int16_t v = vLine[x >> 1] - 128;
            
            int16_t r = roundf(y + v * 1.4);
            int16_t g = roundf(y + u * -0.343 + v * -0.711);
            int16_t b = roundf(y + u * 1.765);
            
            uint8_t *rgb = &rgbBuffer[(row * width + x) * bytesPerPixel];
            rgb[0] = 0xff;
            rgb[1] = clamp(b);
            rgb[2] = clamp(g);
            rgb[3] = clamp(r);
        }
    }
    
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(rgbBuffer, width, height, 8, width * bytesPerPixel, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipLast);
    
    CGImageRef cgImage = CGBitmapContextCreateImage(context);
    CGContextRelease(context);
    CGColorSpaceRelease(colorSpace);
    free(rgbBuffer);
    
    UIImage *image = [UIImage imageWithCGImage:cgImage];
    CGImageRelease(cgImage);
    
    return image;
}

hi can u provide swift version?