7

我在我的控制台中收到这样的错误：

：CGBitmapContextCreate：无效数据字节/行：对于 8 个整数位/分量、3 个分量、kCGImageAlphaPremultipliedFirst，应至少为 1920。: CGBitmapContextCreateImage: 无效的上下文 0x0

我使用下面的代码：

- (UIImage *) imageFromSampleBuffer:(CMSampleBufferRef) sampleBuffer 
{
    // 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 pixel buffer
    void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer); 

    // Get the number of bytes per row for the pixel buffer
    size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); 
    // Get the pixel buffer width and height
    size_t width = CVPixelBufferGetWidth(imageBuffer); 
    size_t height = CVPixelBufferGetHeight(imageBuffer); 

    // 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, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); 
    // 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);
}
4

2 回答 2

18

这就是解决我的问题的原因：正如“Wildaker”所建议的那样，或多或少是“调用它的代码”。

在 Apple 示例中，设置了输出格式。也许你跳过这部分来简化？！

output.videoSettings = [NSDictionary dictionaryWithObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey: (id)kCVPixelBufferPixelFormatTypeKey];

于 2012-11-26T12:16:02.340 回答
0

void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);应改为：uint8_t *baseAddress = (uint8_t*)CVPixelBufferGetBaseAddress(imageBuffer);

于 2013-07-12T08:37:59.710 回答