Est-ce que quelqu'un a un exemple de code pour le traitement vImage sur iOS?
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25-09-2019 - |
Question
J'ai lu tous les bits de la documentation là-bas que je peux trouver, mais ne peut pas obtenir un simple appel vImage à travailler. J'ai juste besoin d'un exemple réel. La documentation est très clairsemée.
La solution
Documentation n'existe pas parce que les bibliothèques vImage ne sont pas disponibles sur iOS.
vImage est disponible sur iOS depuis 5.0. La documentation est ici .
Autres conseils
Si vous traitez la vidéo en temps réel, et votre entrée est traité dans un tampon de pixel, voici comment copier ce tampon dans un vImage, à quel point vous pouvez appeler ce que vous des commandes comme:
- (CVPixelBufferRef)copyRenderedPixelBuffer:(CVPixelBufferRef)pixelBuffer
{
CVPixelBufferLockBaseAddress( pixelBuffer, 0 );
// vImage processing
vImage_Error err;
vImage_Buffer buffer;
buffer.data = (unsigned char *)CVPixelBufferGetBaseAddress( pixelBuffer );
buffer.rowBytes = CVPixelBufferGetBytesPerRow( pixelBuffer );
buffer.width = CVPixelBufferGetWidth( pixelBuffer );
buffer.height = CVPixelBufferGetHeight( pixelBuffer );
vImageCVImageFormatRef vformat = vImageCVImageFormat_CreateWithCVPixelBuffer( pixelBuffer );
vImage_CGImageFormat cgformat = {
.bitsPerComponent = 8,
.bitsPerPixel = 32,
.bitmapInfo = kCGBitmapByteOrderDefault,
.colorSpace = NULL, //sRGB
};
const CGFloat bgColor[3] = {0.0, 0.0, 0.0};
vImageBuffer_InitWithCVPixelBuffer(&buffer, &cgformat, pixelBuffer, vformat, bgColor, kvImageNoAllocate);
vImage_Buffer outbuffer;
void *tempBuffer;
tempBuffer = malloc(CVPixelBufferGetBytesPerRow( pixelBuffer ) * CVPixelBufferGetHeight( pixelBuffer ));
outbuffer.data = tempBuffer;
outbuffer.rowBytes = CVPixelBufferGetBytesPerRow( pixelBuffer );
outbuffer.width = CVPixelBufferGetWidth( pixelBuffer );
outbuffer.height = CVPixelBufferGetHeight( pixelBuffer );
err = vImageEqualization_ARGB8888(&buffer, &outbuffer, kvImageNoFlags);
if(err != -1)
err = vImageContrastStretch_ARGB8888(&buffer, &outbuffer, kvImageNoFlags);
if(err != -1)
err = vImageBuffer_CopyToCVPixelBuffer(&outbuffer, &cgformat, pixelBuffer, vformat, bgColor, kvImageNoFlags);
if(err != -1)
free(tempBuffer);
CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );
return (CVPixelBufferRef)CFRetain( pixelBuffer );
}
Mise à jour de la réponse de Ole Bermann: l'iOS 5.0 a été ajouté cadre Accélérez
.Un exemple encore plus avancé, avec l'optimisation des fonctions d'égalisation et d'étirement (IGNORE commenté le code, mais vous pouvez l'utiliser cela fonctionne-aussi:
- (CVPixelBufferRef)copyRenderedPixelBuffer:(CVPixelBufferRef)pixelBuffer {
CVPixelBufferLockBaseAddress( pixelBuffer, 0 );
unsigned char *base = (unsigned char *)CVPixelBufferGetBaseAddress( pixelBuffer );
size_t width = CVPixelBufferGetWidth( pixelBuffer );
size_t height = CVPixelBufferGetHeight( pixelBuffer );
size_t stride = CVPixelBufferGetBytesPerRow( pixelBuffer );
vImage_Buffer _img = {
.data = base,
.height = height,
.width = width,
.rowBytes = stride
};
vImage_Error err;
vImage_Buffer _dstA, _dstR, _dstG, _dstB;
err = vImageBuffer_Init( &_dstA, height, width, 8 * sizeof( uint8_t ), kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageBuffer_Init (alpha) error: %ld", err);
err = vImageBuffer_Init( &_dstR, height, width, 8 * sizeof( uint8_t ), kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageBuffer_Init (red) error: %ld", err);
err = vImageBuffer_Init( &_dstG, height, width, 8 * sizeof( uint8_t ), kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageBuffer_Init (green) error: %ld", err);
err = vImageBuffer_Init( &_dstB, height, width, 8 * sizeof( uint8_t ), kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageBuffer_Init (blue) error: %ld", err);
err = vImageConvert_ARGB8888toPlanar8(&_img, &_dstA, &_dstR, &_dstG, &_dstB, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageConvert_ARGB8888toPlanar8 error: %ld", err);
err = vImageEqualization_Planar8(&_dstR, &_dstR, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageEqualization_Planar8 (red) error: %ld", err);
err = vImageEqualization_Planar8(&_dstG, &_dstG, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageEqualization_Planar8 (green) error: %ld", err);
err = vImageEqualization_Planar8(&_dstB, &_dstB, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageEqualization_Planar8 (blue) error: %ld", err);
err = vImageConvert_Planar8toARGB8888(&_dstA, &_dstR, &_dstG, &_dstB, &_img, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImageConvert_Planar8toARGB8888 error: %ld", err);
err = vImageContrastStretch_ARGB8888( &_img, &_img, kvImageNoError );
if (err != kvImageNoError)
NSLog(@"vImageContrastStretch_ARGB8888 error: %ld", err);
err = vImagePermuteChannels_ARGB8888(&_img, &_img, map, kvImageNoFlags);
if (err != kvImageNoError)
NSLog(@"vImagePermuteChannels_ARGB8888 error: %ld", err);
free(_dstA.data);
free(_dstR.data);
free(_dstG.data);
free(_dstB.data);
CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );
return (CVPixelBufferRef)CFRetain( pixelBuffer );
}