Christophe, if you are interested in continuing to work in this area, perhaps consider to make a GEGL plugin for MLT as it is continuing to build on its usage of OpenCL: http://libregraphicsworld.org/blog/entry/gegl-developer-sponsored-to-improve-hardware-acceleration-support
On Mon, Nov 14, 2011 at 1:49 PM, Dan Dennedy <[email protected]> wrote: > > On Mon, Nov 14, 2011 at 12:23 PM, Christophe Thommeret <[email protected]> wrote: > > Hi, > > > > First, thanx for this great work, I'm using MLT with the Kdenlive frontend > > to > > edit video (mainly avchd) and it does its job quite well. > > But even with low res video (i use kdenlive's "proxy clip" feature), adding > > a > > simple effect like contrast makes the preview to drop frames. I sure don't > > have > > the strongest cpu around but i think a E8500 is not so bad. > > I've recently played a bit with opengl and found that a simple nvidia GT220 > > can run several glsl filters (say 6, like contrast,brightness...) on a > > 1920x1080, while still displaying 50fps (deinterlaced 25i) ! So you can > > imagine what could be done on lowres ! > > Having a flawless preview is really comfortable :) > > > > I see that opengl is in MLT's todo. So i wonder if you have already some > > thoughts on what should be done and how it should be done. > > I would be happy to help. > > There is already a WebVfx plugin that supports GLSL via JS in > QtWebKit's WebGL. Recently, I added a shader for YCbCr-to-RGB color > conversion for the OpenGL output in a new project I am working on, and > I see its benefit. > > In general, it seems difficult and costly performance-wise to fit GPU > effects into the framework unless you use them entirely. Otherwise, > you end having to do some on the CPU and also keep the full > flexibility and expression of arbitrary filter ordering. Also, one > should consider OpenCL and how either can be combined with hwaccel > decoder output in vendor-independent VA-API, which is still not > integrated. I am not willing to lend much effort to a NVIDIA-only > solution. Also, my experience with VDPAU shows it gets tricky to keep > things stable when you combine it with multiple video tracks, > transitions, and parallel processing, which is why it is not enabled > by default. > > I am slowly learning more about where I want to go with this, but not > aggressively. Feel free to contribute. You might want to contribute > VA-API integration or improve upon VDPAU to get started. Once you want > to move into filters, we will need an image type to represent a > surface or PBO and its converters with the other image types. > > -- > +-DRD-+ -- +-DRD-+ ------------------------------------------------------------------------------ All the data continuously generated in your IT infrastructure contains a definitive record of customers, application performance, security threats, fraudulent activity, and more. Splunk takes this data and makes sense of it. IT sense. And common sense. http://p.sf.net/sfu/splunk-novd2d _______________________________________________ Mlt-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/mlt-devel
