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; }
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); } }