Re: FxPlug using CIImage with CIFilter behave differently between Motion and Final Cut
site_archiver@lists.apple.com Delivered-To: pro-apps-dev@lists.apple.com Dkim-signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:to :subject:cc:in-reply-to:mime-version:content-type :content-transfer-encoding:content-disposition:references; bh=QsDdSR2wvBjpJo/o6QxdAXXt6jKF8QKz5noApcoj0Xk=; b=a8JiSR5LN+A6cqWafXRxotVbL4aXQMhuWZ7FEePOFi+tW/gPjoTCjHbmmSBhC45Ptn VaZQpFhr3mSkTwTJmWacF8GTmHmxTkyRtZxXfw9P8Bpuo29Hty/UXSveCGqSihqmiEVa +Qq6nvF7yPUSgL2PYAKx54tTSTgNAI1fh/4Y0= Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references; b=TULG5a1kT8nOfVHbNyzYGuMxgnYAISzSc5f2nRCdoN85uWrICvCzws/o4ivayY1d94 ZJW1XO69kiK5RR8gDwDtkcGtdjdqQN9OeCsEUKBjbWFHH1qc0g2pAOEDFEk2Tr4aZ3L3 Yc59ToqK3griCi8gpAVLy1lPv/F/Sl+ZhYbwY= Darrin, I am actually never calling release on anything frame or texture related... Things seem to be running ok. The filter is slow for large frame volumes (width of 60 - 150), but the memory foot print stays relatively constant... What is the recommended pattern for allocating/releasing temporalImage frames? Does release need to called explicitly? Could this problem be considered a bug in Motion? or is there a more conventional way for me to go about stringing these filters together successively. Perhaps the CIFilterGenerator class may work in some way? The API for that is a bit confusing, but it seems like it may be useful. Thanks, On Thu, Oct 2, 2008 at 8:34 AM, Darrin Cardani <dcardani@apple.com> wrote:
Jim,
I'll have to think about why you're getting the same texture ID for successive calls, and what you can do about it. There's no real way to tell Motion to give you a different texture ID than the one it decides to give you. But I'm a little surprised that it's giving you the same one when you're not releasing the previous one. (And you better release them all eventually or you'll run out of resources!)
If you want to cache the frames, you could get bitmaps instead of textures and keep them around. However, this will make it more difficult for the host app to cache other things. You'll also have to upload the images to a texture yourself every time you want to use them. But I guess that wouldn't be any slower than having the host app do it. In Motion, we may already be caching the input frames as bitmaps in memory. (If your filter is the only one applied to the footage, then that's already happening.) You probably don't want to do it yourself, though, because if there are other filters applied before yours, and the user changes the parameters of those filters, you have no way to know which frames in your cache have changed and which haven't. So I don't recommend doing that.
One option would be to draw the intermediate steps manually, and feed each output to the next input after it's been rendered. This will reduce performance, of course. Not the best solution, but probably one that can work.
Darrin
On Oct 1, 2008, at 5:23 PM, Jim George wrote:
good thinking, I did a print of the texture ID. In Motion it is always the same, but in final cut it is always different.
I am not releasing the texture within the loop. doing so actually causes a crash.
does anyone have any ideas what to do to ensure that new textures get allocated each iteration?
On a related note, is there anyway that i can cache these frames into some sort of LRU expulsion cache. Most of the time, especially during render, each frame of out put uses almost the same frames of input but I am not storing them locally at all. If i could store them and reduce the number of calls to temporalImageAPI perhaps that would help performance?
Thanks!
On Thu, Oct 2, 2008 at 1:28 AM, Darrin Cardani <dcardani@apple.com> wrote:
On Oct 1, 2008, at 12:22 AM, Jim George wrote:
I've run into a discrepancy between the behavior of using Core Image filters between Final Cut and Motion in an FxPlug and wonder if anyone would have any insight into the problem. I have a filter that takes a number of contiguous frames and runs some processing over them. I am using the temporalImageAPI to get the frames as FxTextures. In Final Cut the filter comes out correctly, but in Motion only the *last* frame gets drawn. I'm thinking somehow that Motion uses a shared context or texture where final cut allocates new ones, but my understanding of these under the hood is a bit of guesswork.
Jim, Yes there are cases where Motion reuses textures. You could check whether we're giving you the same texture by printing out the texture ID in the loop. I would think that since you aren't releasing the textures (at least in the code below) that we wouldn't be reusing the texture ID. If this is a cut-down version of the code and you actually are releasing the textures after each loop iteration, that may be the issue. Try not releasing them until after the draw command. Remember that CI filters don't actually execute until you call the drawImage: command because they can concatenate for improved speed, so if you're releasing them in the loop, they might not be there when the drawing happens.
Below is the basics of what I'm doing in the Render method for FxPlug.
glPushAttrib(GL_CURRENT_BIT); CIContext *ciContext = [CIContext contextWithCGLContext:CGLGetCurrentContext()
pixelFormat:CGLGetPixelFormat(CGLGetCurrentContext()) options:NULL]; CGColorSpaceRef cspace = CGColorSpaceCreateDeviceRGB(); FxTexture* inputTex; [temporalImageAPI getInputTexture:&inputTex withInfo: renderInfo atTime: renderInfo.frame - width/2]; CIImage* imageBase = [CIImage imageWithTexture:[inputTex textureId] size:CGSizeMake([inputTex width],[inputTex height]) flipped:NO colorSpace:cspace]; UInt32 frameStep = 0; double i; for(i = renderInfo.frame - width/2; i <= renderInfo.frame + width/2; i++){ [_filter setValue:imageBase forKey: @"inputBase"]; [temporalImageAPI getInputTexture:&inputTex withInfo: renderInfo atTime:i]; CIImage* inputImage = [CIImage imageWithTexture:[inputTex textureId] size:CGSizeMake([inputTex width],[inputTex height]) flipped:NO colorSpace:cspace]; [_filter setValue:inputImage forKey:@"inputImage"]; imageBase = [_filter valueForKey:@"outputImage"]; } [ciContext drawImage:imageBase inRect:CGRectMake(left,bottom,right-left,top-bottom) fromRect:CGRectMake(tLeft,tBottom,tRight-tLeft,tTop-tBottom)]; glPopAttrib();
Darrin -- Darrin Cardani dcardani@apple.com
-- - Jim www.INTelegance.net
-- Darrin Cardani dcardani@apple.com
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Jim George