[ogg-dev] gstreamer oggmux and variable framerate

[Alexey Fisher]

On Do, 2010-08-19 at 11:41 -0400, Benjamin M. Schwartz wrote:
> On 08/19/2010 11:29 AM, Timothy B. Terriberry wrote:
> > Alexey Fisher wrote:
> >> My question is: should actually ogg support timestamps, also variable
> >> framerate? If yes: it seems to be some where broken.
> > 
> > The Ogg mapping for Theora is fixed-framerate. You can hack something 
> > into Ogg by using a higher framerate and inserting "duplicate frame" 
> > packets (which cost approximately one byte each, including the container 
> > overhead), but AFAIK there is no gstreamer support for doing this 
> > automatically.

hmm... this will be good to have. 

> The best solution I know of is to use the "videorate" element to convert
> the stream into a form that theoraenc can handle:
> 
> http://www.gstreamer.net/data/doc/gstreamer/head/gst-plugins-base-plugins/html/gst-plugins-base-plugins-videorate.html

videorate cause us performance problems on Cheese. The source is
normally a webcam which change rate depending on light. On my netbook
buildin webcam tell it support 30fps. With good light it give 4fps. So
most of the CPUtime videorate will make theora encoding duplicate
frames.