[theora-dev] dynamic change video quality........

xiphmont at xiph.org xiphmont at xiph.org
Tue Feb 19 05:07:39 PST 2008


On Feb 19, 2008 7:17 AM, Asanka Dilruk <adilruk at gmail.com> wrote:
> Hi monty..
>    Actually i wanted to change video quality according to the available
> bandwidth of the network to get better streaming performance. So i thought
> if i can change video quality value to do that. can i change video quality
> value frame by frame.

Are you possibly confusing 'quality mode' and 'managed bitrate mode'?

In the quality modes, Theora attempts to maintain roughly identical
perceived SNR from frame to frame.  It makes no attempt to influence
bitrate and indeed bitrate can swing wildly as the video content
varies.

In managed bitrate modes, Theora attemps to hold the average bitrate
constant regardless of the video content.  In essence, it lets quality
vary to keep the bitrate within selected limits.

The description of your application would seem to imply that you want
to use the managed bitrate mode, but occasionally change the bitrate
management parameters to reflect changes in the channel's available
bandwidth.

Monty


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