Databases
StackOverflow2013
Postsdbo
POhow to convert a CVImageBufferRef to UIImage
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POhow to convert a CVImageBufferRef to UIImage
    primarykey
    data
    text
    <p>I am trying to capture video from a camera. i have gotten the <code>captureOutput:didOutputSampleBuffer:</code> callback to trigger and it gives me a sample buffer that i then convert to a <code>CVImageBufferRef</code>. i then attempt to convert that image to a <code>UIImage</code> that i can then view in my app.</p> <pre><code>- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection { CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBuffer); /*Lock the image buffer*/ CVPixelBufferLockBaseAddress(imageBuffer,0); /*Get information about the image*/ uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer); size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer); size_t width = CVPixelBufferGetWidth(imageBuffer); size_t height = CVPixelBufferGetHeight(imageBuffer); /*We unlock the image buffer*/ CVPixelBufferUnlockBaseAddress(imageBuffer,0); /*Create a CGImageRef from the CVImageBufferRef*/ CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst); CGImageRef newImage = CGBitmapContextCreateImage(newContext); /*We release some components*/ CGContextRelease(newContext); CGColorSpaceRelease(colorSpace); /*We display the result on the custom layer*/ /*self.customLayer.contents = (id) newImage;*/ /*We display the result on the image view (We need to change the orientation of the image so that the video is displayed correctly)*/ UIImage *image= [UIImage imageWithCGImage:newImage scale:1.0 orientation:UIImageOrientationRight]; self.capturedView.image = image; /*We relase the CGImageRef*/ CGImageRelease(newImage); } </code></pre> <p>the code seems to work fine up until the call to <code>CGBitmapContextCreate</code>. it always returns a <code>NULL</code> pointer. so consequently none of the rest of the function works. no matter what i seem to pass it the function returns null. i have no idea why.</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USdaurnimator
    1. USiHorse
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    3. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POhow to convert a CVImageBufferRef to UIImage
      1. USOscar
      1. VTFavorite
    2. VO
      singulars
      1. POhow to convert a CVImageBufferRef to UIImage
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POhow to convert a CVImageBufferRef to UIImage
      1. This table or related slice is empty.
      1. VTUpMod
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload