theora performance

[tsr]

Hi guys.

Its been a couple of years that I have been using VLC to fulfill my streaming needs, and I have not been able to get over the fact that my server does not have enough CPU power to stream theora video on the fly. I know that theora has been in an experimental (i.e. "lets develop it further") stage, and I assume that the ffmpeg team is responsible for the development of this codec, rather than the VLC team. But I have been wondering... will I ever be able to stream theora video on my weak AMD XP 3000+ CPU ? Any insights, anyone ?

[Jean-Baptiste Kempf]

Theora is not developped by ffmpeg but by theora guys (Ogg/Xiph.org). You should have enough power, but VLC may be a bit broken with theora transcoding.

[tsr]

oh, thanks for the input.
i now remember that i got the info about theora being in a "development" state from xiph.org, but i confused it with ffmpeg. either way, i have not yet heard from either source about an optimized theora encoder.
so is it really true that my servers CPU should be able to handle on-the-fly theora encoding ? if so, do you happen to know any scriptable commandline tools that allow streaming/encoding theora ? a complicated mplayer decoding/other tool encoding/yet something else for streaming solution would be quite fine by me.

[Lucas Malor]

Well, now Theora is no more at experimental stage, and I must say VLC is very slow to play them too. ffmpeg's fault?

PS: to encode to theora:

Code: Select all

ffmpeg -i INPUT -f ogg -vcodec libtheora -acodec libvorbis -b 866000 -ab 80000 OUTPUT.ogv

For better results, raise -b parameter.

[Rémi Denis-Courmont]

VLC uses the official libtheora to encode and decode Theora. It might be that FFmpeg is faster. You can select the encoder or decoder in VLC explicitly if you want.

[Lucas Malor]

I changed Stream output -> Muxers to ffmpeg but it is still slow. Was I wrong?

[Rémi Denis-Courmont]

It's about ENCODERS, not MUXERS.

[Lucas Malor]

Ok, I changed it in the Transcode prefs and it seems a bit faster indeed. Anyway for what I know this means ffmpeg is applied to all codecs, not only to theora. How can I do this?