Category: Video

Video related stuff

How to overlay a bitmap on top of video with Video Mixing Renderer (VMR-9)

A 100-lines code snippet which illustrates how a bitmap is overlaid over displayed video with Video Mixing Renderer 9 Filter using IVMRMixerBitmap9 interface. A video clip is played (default is Windows clock.avi, but you can replace it with your longer one to see overlay is really in a loop). http://code.assembla.com/…/VmrMixerBitmapSample01/… VMR9AlphaBitmap AlphaBitmap; ZeroMemory(&AlphaBitmap, sizeof AlphaBitmap);…

Read the full article

Windows Media Codec List

Windows Media Codec List utility uses IWMCodecInfo interface (see also IWMCodecInfo2, IWMCodecInfo3) lists installed Windows Media Codecs and their formats and presents the findings in a convenient way. The utility gives a quick idea what a programmer would obtain through IWMCodecInfo2/IWMCodecInfo3 interfaces and what well known format structures (WM_MEDIA_TYPE, AM_MEDIA_TYPE, WAVEFORMATEX, VIDEOINFOHEADER) correspond to particular…

Read the full article

Another third party DirectShow filter that may break your very own application

One of the DirectShow’s most important features is Intelligent Connect, which allows Filter Graph Manager to build graphs out of independent filters trying to connect them together including options to fall back to originally non-preferred alternatives and so on. It is however important that filters are properly registered with the Filter Mapper. For the developers…

Read the full article

Video Decoder DMO and AM_SAMPLE_PREROLL

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…

Read the full article