// Oprogramowanie Roman Ryltsov
This is presumably a bug in Windows Media Video 9 Encoder in versions up to Windows 7 included (fixed in Windows 8.1 at the very least – wmvencod.dll 6.3.9600.17415). A IMediaObject::Discontinuity call destroys input the DMO it already holds: it reports success, and handles discontinuity correctly. It even drains output as it should, but if in the same time…
Since Microsoft Windows Vista, Media Foundation API offers a set of convenient Digital Signal Processors for video and audio processing. These include conversion helpers for video and audio, dual interfaced as Media Foundation Transforms (MFTs) and DirectX Media Objects (DMOs). Earlier posts shed some light on DMO interfaces, and use of DMOs in DirectShow graphs…
As libx264 has so many presets and tunes, I was curious how they all related one to another when it comes to encode video info H.264. I was more interested in single pass encoding for live video, so the measurements are respectively for this mode of operation with encoder running in CRF (constant rate factor,…
Matthew van Eerde already made a similar wrapper over MFTEnumEx in How to enumerate Media Foundation transforms on your system, and this one extends it with enumeration of attributes, also listing them in human friendly way. This sort of code should perhaps have been in Media Foundation SDK Samples, however we have what we have.…
Windows Vista introduced helpful video and audio Digital Signal Processors (DSPs) in DMO form-factor, which however do not work smoothly with DMO Wrapper Filter and thus cannot be directly used in DirectShow. There perhaps was no intent in first place to extend DirectShow functionality with these new components, and no effort was put into providing…
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…