// Oprogramowanie Roman Ryltsov
Sharing memory allocators between input and output pins is an important concept to keep performance of filter graph. Unlike more frequent scenario with different allocators, a filter (referred to as “middle filter” below) which has equal media types on input and output pins has an advantage to avoid memory-to-memory copy operation for every frame processed,…
As an appreciation of outstanding contributions in DShow/Media Foundation technical communities during the past year I was presented with the 2009 Microsoft® MVP Award, which I am very much pleased to receive. In an intention to accompany the post with useful DirectShow related information, here is the link list of most important DirectShow resources on…
Another example of a negligence with a cost of incompatibility and enormous amount of support time. Ahead Nero installs a number of DirectShow filters into $(Program Files)\Common Files\Ahead\DSFilter directory. One of the files is NeResize.ax and it hosts a Nero Resize filter. Let us take a closer look: CLSID: {30002E0C-C574-481E-A5DE-90AE54A79E10} (note that Nero 8 ships…
I have been receiving comments that Filter Graph Spy tool does not work with Microsoft Vista operating system. I never had a moment to check until recently, and this time I realized that it really does not work. I am definitely aware of dramatic changes introduced with this operating system, and in particular UAC feature,…
With a lot of DirectShow Filter Graphs published on Running Object Table, especially those automatically published by Filter Graph Spy utility, it might be a bit tricky to locate your graph of interest in the list. Filter graphs are published with a textual moniker item name of predefined format, which is recognized by GraphEdit or…
This does not seem to be documented anywhere, so it makes sense to mention. A video decoder, wrapped by DMO Wrapper Filter, will receive preroll media samples with AM_SAMPLE_PREROLL flag (alternatively available using IMediaSample::IsPreroll), but it won’t even forward these samples to the underlying DMO, instead they are just ignored. MSDN says: Preroll samples are…
Recently it was the time to sort out an issue with a video DMO, which outputs YV12 video and in the same time is capable of supporting extended video strides in order to efficiently make a direct connection to Video Mixing Renderer Filters. From past experience, I already knew that some bugs are definitely involved…