[gst-devel] [PATCH] Make theoraenc expose the new "Speed level" property
donny.viszneki at gmail.com
Wed Feb 18 23:12:07 CET 2009
On Wed, Feb 18, 2009 at 4:11 PM, Benjamin M. Schwartz
<bmschwar at fas.harvard.edu> wrote:
> 1. At fixed quality, removing the motion vectors makes the codec less
> efficient if the scene has motion. My test did (some youtube music
> video), and so, at fixed nominal quality, the bitrate increased by 25%.
> That increase in bitrate means more bits to push into memory, which slows
> things down. Non-moving scenes should not experience an increased
> bitrate, and so potentially may be accelerated better.
> 2. The motion-vector search can be implemented many ways. A naive search
> (I hear libtheora-1.0 has a fairly naive implementation) takes a similar
> amount of time regardless of the underlying scene. A very advanced search
> (I hear libtheora-1.1 will have a fancier motion search) might quickly
> detect the lack of motion and stop searching. In any case, with
> speedlevel=2 no search will be performed, and the speed gain depends on
> how much time that search would have taken.
Instead of a music video, try something more typical of what a webcam
captures when people are sitting in front of their webcam: a
relatively static background, and someone in front of the camera
talking. I'd be very interested to see how this affects the results
with libtheora 1.1
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