我有一个IYUV（4：2：0）格式的视频流，并试图将其转换为CVPixelBufferRef，然后转换为CMSampleBufferRef并以AVSampleBufferDisplayLayer播放（需要AVPictureInPictureController）。我已经尝试了几个版本的解决方案，但没有一个实际上工作得很好，希望有视频处理经验的人可以告诉我这里做错了什么。
全功能：

- (CMSampleBufferRef)makeSampleBufferFromTexturesWithY:(void *)yPtr U:(void *)uPtr V:(void *)vPtr yStride:(int)yStride uStride:(int)uStride vStride:(int)vStride width:(int)width height:(int)height doMirror:(BOOL)doMirror doMirrorVertical:(BOOL)doMirrorVertical
{
    NSDictionary *pixelAttributes = @{(NSString *)kCVPixelBufferIOSurfacePropertiesKey:@{}}; // For 1,2,3
    
    CVPixelBufferRef pixelBuffer = NULL;
    CVReturn result;
    result = CVPixelBufferCreate(kCFAllocatorDefault,
                                 width,
                                 height,
                                 kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange // For 1,2,3
//                                 kCVPixelFormatType_32BGRA, // For 4.
                                 (__bridge CFDictionaryRef)(pixelAttributes),
                                 &pixelBuffer);
    if (result != kCVReturnSuccess) {
        NSLog(@"PIP: Unable to create cvpixelbuffer %d", result);
        return nil;
    }

/// Converter code below...

    CMFormatDescriptionRef formatDesc;
    result = CMVideoFormatDescriptionCreateForImageBuffer(kCFAllocatorDefault, pixelBuffer, &formatDesc);
    if (result != kCVReturnSuccess) {
        NSAssert(NO, @"PIP: Failed to create CMFormatDescription: %d", result);
        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
        return nil;
    }
    
    CMTime now = CMTimeMakeWithSeconds(CACurrentMediaTime(), 1000);
    CMSampleTimingInfo timingInfo;
    timingInfo.duration = CMTimeMakeWithSeconds(1, 1000);
    timingInfo.presentationTimeStamp = now;
    timingInfo.decodeTimeStamp = now;
    
    @try {
        if (@available(iOS 13.0, *)) {
            CMSampleBufferRef sampleBuffer;
            CMSampleBufferCreateReadyWithImageBuffer(kCFAllocatorDefault, pixelBuffer, formatDesc, &timingInfo, &sampleBuffer);
//            CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
            CVPixelBufferRelease(pixelBuffer);
            pixelBuffer = nil;
//            free(dest.data);
//            free(uvPlane);
            
            return sampleBuffer;
        } else {
            CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
            return nil;
        }
    } @catch (NSException *exception) {
        NSAssert(NO, @"PIP: Failed to create CVSampleBuffer: %@", exception);
        CVPixelBufferUnlockBaseAddress(pixelBuffer, 0);
        return nil;
    }
}

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以下是我找到的一些解决方案：
1.合并UV，但一半底部是绿色的。

CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    uint8_t *yDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
    memcpy(yDestPlane, yPtr, width * height);

    CGFloat uPlaneSize =  width * height / 4;
    CGFloat vPlaneSize = width * height / 4;
    CGFloat numberOfElementsForChroma = uPlaneSize + vPlaneSize;
    // for simplicity and speed create a combined UV panel to hold the pixels
    uint8_t *uvPlane = calloc(numberOfElementsForChroma, sizeof(uint8_t));
    memcpy(uvPlane, uPtr, uPlaneSize);
    memcpy(uvPlane += (uint8_t)(uPlaneSize), vPtr, vPlaneSize);
    uint8_t *uvDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
    memcpy(uvDestPlane, uvPlane, numberOfElementsForChroma);

型
1.交错U和V，图像仍然扭曲

CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    uint8_t *yDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
    for (int i = 0, k = 0; i < height; i ++) {
        for (int j = 0; j < width; j ++) {
            yDestPlane[k++] = ((unsigned char *)yPtr)[j + i * yStride];
        }
    }
    uint8_t *uvDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
    for (int row = 0, index = 0; row < height / 2; row++) {
        for (int col = 0; col < width / 2; col++) {
            uvDestPlane[index++] = ((unsigned char *)uPtr)[col + row * uStride];
            uvDestPlane[index++] = ((unsigned char *)vPtr)[col + row * vStride];
        }
    }

型
1.有些类似于1。

int yPixels = yStride * height;
    int uPixels = uStride * height/2;
    int vPixels = vStride * height/2;
    CVPixelBufferLockBaseAddress(pixelBuffer, 0);
    uint8_t *yDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 0);
    memcpy(yDestPlane, yPtr, yPixels);

    uint8_t *uvDestPlane = CVPixelBufferGetBaseAddressOfPlane(pixelBuffer, 1);
    memcpy(uvDestPlane , uPtr, uPixels);
    memcpy(uvDestPlane + uPixels, vPtr, vPixels);

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1.使用Accelerate将YUV转换为BGRA，然后转换为CVPixelBuffer，没有错误但没有渲染视频

vImage_Buffer srcYp = {
        .width = width,
        .height = height,
        .rowBytes = yStride,
        .data = yPtr,
    };
    vImage_Buffer srcCb = {
        .width = width / 2,
        .height = height / 2,
        .rowBytes = uStride,
        .data = uPtr,
    };
    vImage_Buffer srcCr = {
        .width = width / 2,
        .height = height / 2,
        .rowBytes = vStride,
        .data = vPtr,
    };

    vImage_Buffer dest;
    dest.data = NULL;
    dest.width = width;
    dest.height = height;

    vImage_Error error = kvImageNoError;
    error = vImageBuffer_Init(&dest, height, width, 32, kvImagePrintDiagnosticsToConsole);
    // vImage_YpCbCrPixelRange pixelRange = (vImage_YpCbCrPixelRange){ 0, 128, 255, 255, 255, 1, 255, 0 };
    vImage_YpCbCrPixelRange pixelRange = { 16, 128, 235, 240, 255, 0, 255, 0 };
    vImage_YpCbCrToARGB info;
    error = kvImageNoError;
    error = vImageConvert_YpCbCrToARGB_GenerateConversion(kvImage_YpCbCrToARGBMatrix_ITU_R_601_4,
                                                          &pixelRange,
                                                          &info,
                                                          kvImage420Yp8_Cb8_Cr8,
                                                          kvImageARGB8888,
                                                          kvImagePrintDiagnosticsToConsole);
    error = kvImageNoError;
    uint8_t permuteMap[4] = {3, 2, 1, 0}; // BGRA - iOS only support BGRA
    error = vImageConvert_420Yp8_Cb8_Cr8ToARGB8888(&srcYp,
                                                   &srcCb,
                                                   &srcCr,
                                                   &dest,
                                                   &info,
                                                   permuteMap, // for iOS must be no NULL, mac can be NULL iOS only support BGRA
                                                   255,
                                                   kvImagePrintDiagnosticsToConsole);

    if (error != kvImageNoError) {
        NSAssert(NO, @"PIP: vImageConvert error %ld", error);
        return nil;
    }

    // vImageBuffer_CopyToCVPixelBuffer will give out error destFormat bitsPerComponent = 0 is not supported
//    vImage_CGImageFormat format = {
//        .bitsPerComponent = 8,
//        .bitsPerPixel = 32,
//        .bitmapInfo = (CGBitmapInfo)kCGBitmapByteOrder32Little | kCGImageAlphaNoneSkipFirst,
//        .colorSpace = CGColorSpaceCreateDeviceRGB()
//    };
//    vImageCVImageFormatRef vformat = vImageCVImageFormat_CreateWithCVPixelBuffer(pixelBuffer);
//
//    error = vImageBuffer_CopyToCVPixelBuffer(&dest, &format, pixelBuffer, vformat, 0, kvImagePrintDiagnosticsToConsole);

    result = CVPixelBufferCreateWithBytes(kCFAllocatorDefault,
                                          width,
                                          height,
                                          kCVPixelFormatType_32BGRA,
                                          dest.data,
                                          dest.rowBytes,
                                          NULL,
                                          NULL,
                                          (__bridge CFDictionaryRef)pixelAttributes,
                                          &pixelBuffer);

型