Hi there, I have just read in the documentation that Theora doesn't support variable frame rates. I don't know whether it will support it in the near future and since I cannot code I don't really know whether this would be easy to implement. But I'd ask you to consider implementing variable frame rates. The reason for that implementation would come from the much smaller size in screencasts and presentations. Screencasts can benefit if the frames are recorded only when something in the screen or selected area changes (this would be even more useful if mouse pointer isn't recorded). And for presentations, I have the following example: http://lessig.blip.tv/. Setting a constant frame rate to one frame per second (which would give wrong audio sync) the total number of frames would be higher with that constant frame rate than with a variable frame rate that only records frames when slides change. Because of these, I think that considering the implementation of variable frame rates would be extremely useful for screencasts and sharing presentations on the net. Could you please consider this implementation. Many thanks for the excellent work on theora, Pablo
On Tue, Nov 11, 2008 at 11:45 AM, Pablo Rodr?guez <oinos at web.de> wrote:>[...]. But I'd ask you to consider implementing > variable frame rates. > > The reason for that implementation would come from the much smaller size > in screencasts and presentations.We don't have any plans to add variable framerates to theora. There is a work around. Duplicating the previous frame is relatively cheap, so an encoder could set something like 5 fps, but only update the image when there's a change. The current encoder isn't smart enough to do this automatically, but a screencast app could force it. The other point is that theora isn't the best format for most presentations. I'd like to store them as an image stream, which can be variable framerate, or use a queue track like cmml to trigger slide advance in an adjacent viewer that holds the whole presentation. For presentations and screencasts with a lot of motion or animation video makes sense though. Are you working on anything with screencasts and theora? -r