Original Post
I'm playing with DirectShow in general and VMR9 renderless mode in particular. The result is ok as I can smoothly render multiple videos while the engine runs at full speed. No flickering, no frames lost in fullscreen or windowed mode, looping is also fine! Unluckly when I turn on debug version of Direct3D9 I get a lot of errors ("Direct3D9: (ERROR) :Error trying to lock driver surface")... "a lot" means they keep increasing as the application runs! :( After some tests I discovered the following: 1- the lock problem has nothing to do with video texture rendering, as it shows up even I don't use those textures. 2- the lock problem has nothing to do with the engine, since the errors disappear if I'm playing ONE video and I render my video texture on screen. 3- the lock problem has nothing to do with stretchrect call in PresentImage as it shows up even if I comment it. Googling resulted in a few posts by people experiencing the same problem but no clear solution emerged from those topics. I'm stuck as I don't know how to solve this problem. I suppose the error happens when VMR9 decodes the video into the first surface (the source of my stretchrect operation). I'd like to know if somebody experienced a similar problem with VMR9. Thank you.