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    <p>If you switch the pixel format from <code>kCVPixelFormatType_420YpCbCr8BiPlanarFullRange</code> to <code>kCVPixelFormatType_32BGRA</code> (at line 315 of RippleViewController) then <code>captureOutput:didOutputSampleBuffer:fromConnection:</code> will receive a sample buffer in which the image buffer can be uploaded straight to OpenGL via <code>glTexImage2D</code> (or <code>glTexSubImage2D</code> if you want to keep your texture sized as a power of two). That works because all iOS devices to date support the <code>GL_APPLE_texture_format_BGRA8888</code> extension, allowing you to specify an otherwise non-standard format of <code>GL_BGRA</code>.</p> <p>So you'd create a texture somewhere in advance with <code>glGenTextures</code> and replace line 235 with something like:</p> <pre><code>glBindTexture(GL_TEXTURE_2D, myTexture); CVPixelBufferLockBaseAddress(pixelBuffer); glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, CVPixelBufferGetWidth(pixelBuffer), CVPixelBufferGetHeight(pixelBuffer), GL_BGRA, GL_UNSIGNED_BYTE, CVPixelBufferGetBaseAddress(pixelBuffer)); CVPixelBufferUnlockBaseAddress(pixelBuffer); </code></pre> <p>You may want to check that the result of <code>CVPixelBufferGetBytesPerRow</code> is four times the result of <code>CVPixelBufferGetWidth</code>; I'm uncertain from the documentation whether it's guaranteed always to be (which, pragmatically, probably means that it isn't), but as long as it's a multiple of four you can just supply <code>CVPixelBufferGetBytesPerRow</code> divided by four as your pretend width, given that you're uploading a sub image anyway.</p> <p>EDIT: in response to the follow-on question posted below as a comment, if you wanted to stick with receiving frames and making them available to the GPU in YUV then the code becomes visually ugly because what you're returned is a structure pointing to the various channel components but you'd want something like this:</p> <pre><code>// lock the base address, pull out the struct that'll show us where the Y // and CbCr information is actually held CVPixelBufferLockBaseAddress(pixelBuffer); CVPlanarPixelBufferInfo_YCbCrBiPlanar *info = CVPixelBufferGetBaseAddress(imageBuffer); // okay, upload Y. You'll want to communicate this texture to the // SamplerY uniform within the fragment shader. glBindTexture(GL_TEXTURE_2D, yTexture); uint8_t *yBaseAddress = (uint8_t *)info + EndianU32_BtoN(info-&gt;componentInfoY.offset); uint32_t yRowBytes = EndianU32_BtoN(info-&gt;componentInfoY.rowBytes); /* TODO: check that yRowBytes is equal to CVPixelBufferGetWidth(pixelBuffer); otherwise you'll need to shuffle memory a little */ glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, CVPixelBufferGetWidth(pixelBuffer), CVPixelBufferGetHeight(pixelBuffer), GL_LUMINANCE, GL_UNSIGNED_BYTE, yBaseAddress); // we'll also need to upload the CbCr part of the buffer, as a two-channel // (ie, luminance + alpha) texture. This texture should be supplied to // the shader for the SamplerUV uniform. glBindTexture(GL_TEXTURE_2D, uvTexture); uint8_t *uvBaseAddress = (uint8_t *)info + EndianU32_BtoN(info-&gt;componentInfoCbCr.offset); uint32_t uvRowBytes = EndianU32_BtoN(info-&gt;componentInfoCbCr.rowBytes); /* TODO: a check on uvRowBytes, as above */ glTexSubImage2D(GL_TEXTURE_2D, 0, 0, 0, CVPixelBufferGetWidth(pixelBuffer)/2, CVPixelBufferGetHeight(pixelBuffer)/2, GL_LUMINANCE_ALPHA, GL_UNSIGNED_BYTE, uvBaseAddress); CVPixelBufferUnlockBaseAddress(pixelBuffer); </code></pre>
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    1. POHow can I rewrite the GLCameraRipple sample without using iOS 5.0-specific features?
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    1. COFor the record, this turns out to be almost exactly the same answer as Brad's but half a minute later. I'm taking that as a compliment. I'm going to leave it here though, in case my line number references into the nominated Apple project are of any help.
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    2. COThanks to your answer, bu if I want to use kCVPixelFormatType_420YpCbCr8BiPlanarFullRange without using iOS 5.0-specific features, how should I do?
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    3. COHaving poked into the shaders, it looks like Apple are already doing a YUV to RGB conversion in there, so you'd upload the Y and UV components as two separate textures (luminance and luminance+alpha respectively, I'd imagine). Give me a few minutes and I'll try to update my answer accordingly...
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