CODEWITHSUNDEEP
iphoneiosuiimageavfoundation
Nims
Nims

Reputation: 431

CGBitmapContextCreateImage error

I am getting error like this In my console:

: CGBitmapContextCreate: invalid data bytes/row: should be at least 1920 for 8 integer bits/component, 3 components, kCGImageAlphaPremultipliedFirst. : CGBitmapContextCreateImage: invalid context 0x0

I use below code:

- (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);
}

Upvotes: 7

Views: 4803

Answers (2)

easonwzs
easonwzs

Reputation: 3

void *baseAddress = CVPixelBufferGetBaseAddress(imageBuffer);should be changed to : uint8_t *baseAddress = (uint8_t*)CVPixelBufferGetBaseAddress(imageBuffer);

Upvotes: 0

user1853312
user1853312

Reputation: 206

this is what fixed my problem: as "Wildaker" suggested, it is "the code that's calling it", more or less.

in the Apple Example the output format is set. perhaps you skipped this part to simplify ?!

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

Upvotes: 18

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