ios - 如何从vImage_Buffer转到CVPixelBufferRef

我正在我的iOS应用中录制实时视频。在另一个Stack Overflow page上，我发现您可以使用vImage_Buffer在我的框架上工作。
问题是我不知道如何从输出的CVPixelBufferRef返回到vImage_buffer。
这是另一篇文章中给出的代码:

NSInteger cropX0 = 100,
          cropY0 = 100,
          cropHeight = 100,
          cropWidth = 100,
          outWidth = 480,
          outHeight = 480;

CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer,0);
void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);

vImage_Buffer inBuff;
inBuff.height = cropHeight;
inBuff.width = cropWidth;
inBuff.rowBytes = bytesPerRow;

int startpos = cropY0 * bytesPerRow + 4 * cropX0;
inBuff.data = baseAddress + startpos;

unsigned char *outImg = (unsigned char*)malloc(4 * outWidth * outHeight);
vImage_Buffer outBuff = {outImg, outHeight, outWidth, 4 * outWidth};

vImage_Error err = vImageScale_ARGB8888(&inBuff, &outBuff, NULL, 0);
if (err != kvImageNoError) NSLog(@" error %ld", err);

现在，我需要将outBuff转换为CVPixelBufferRef。
我假设我需要使用vImageBuffer_CopyToCVPixelBuffer，但是我不确定如何使用。
我的初次尝试失败，出现了EXC_BAD_ACCESS: CVPixelBufferUnlockBaseAddress(imageBuffer, 0);

CVPixelBufferRef pixelBuffer;
CVPixelBufferCreate(kCFAllocatorSystemDefault, 480, 480, kCVPixelFormatType_32BGRA, NULL, &pixelBuffer);

CVPixelBufferLockBaseAddress(pixelBuffer, 0);

vImage_CGImageFormat format = {
    .bitsPerComponent = 8,
    .bitsPerPixel = 32,
    .bitmapInfo = kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,  //BGRX8888
    .colorSpace = NULL,  //sRGB
};

vImageBuffer_CopyToCVPixelBuffer(&outBuff,
                                 &format,
                                 pixelBuffer,
                                 NULL,
                                 NULL,
                                 kvImageNoFlags);  // Here is the crash!


CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);

任何想法？

最佳答案

NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
    [NSNumber numberWithBool : YES], kCVPixelBufferCGImageCompatibilityKey,
    [NSNumber numberWithBool : YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
    [NSNumber numberWithInt : 480], kCVPixelBufferWidthKey,
    [NSNumber numberWithInt : 480], kCVPixelBufferHeightKey,
    nil];

status = CVPixelBufferCreateWithBytes(kCFAllocatorDefault,
                                      480,
                                      480,
                                      kCVPixelFormatType_32BGRA,
                                      outImg,
                                      bytesPerRow,
                                      NULL,
                                      NULL,
                                      (__bridge CFDictionaryRef)options,
                                      &pixbuffer);

您应该像上面一样生成一个新的pixelBuffer。