[theora] Reading framerate, height, width from Theora file

[Cristian Adam]

On 30/12/2009 09:23, Silvia Pfeiffer wrote:
> Maybe the DirectShow filters can help you get started?
> http://svn.xiph.org/trunk/oggdsf/
>
> Cheers,
> Silvia.
>

The DirectShow filters can help but it's not that straightforward.

One needs to build a small DirectShow graph and then interrogate the
output pin of Theora Decoder for the VIDEOINFOHEADER2 data structure.

The rcSource field will contain the height and width of the movie
and the AvgTimePerFrame field will help in computing the framerate.

One can test this easily by using GraphStudio 
(http://blog.monogram.sk/janos/tools/monogram-graphstudio/).

DirectShow.NET should be used when using DirectShow in .NET languages.

I am planning on implementing the IMediaDet Interface for the Theora
Decoder 
(http://msdn.microsoft.com/en-us/library/dd390180%28VS.85%29.aspx) which 
will help in cases like this. But I
cannot give an estimate.

The C# Theora Decoder might be of more use in this case:
http://www.wreckedgames.com/downloads/cSharpTheora.zip

Cheers,
Cristian.