[MPlayer-users] ogg

[D Richard Felker III]

On Sun, Sep 12, 2004 at 08:17:15PM +0200, Ulrich Schweitzer wrote:
> On Sunday 12 September 2004 20:03, D Richard Felker III wrote:
> 
> > avi container works only with constant-bitrate or constant-framerate
> > audio. vorbis is neither.
> 
> ogg vorbis can be created with constant bitrate (with the --managed option 
> in oggenc). It's not recommended as vbr of course has a better quality, 
> but cbr is possible (and should have a better audio quality than mp3 at 
> the same bitrate).

um, most definitely not. at bitrates needed for good quality, vorbis
doesn't even outperform lame by that much in quality, and that's with
full vbr. in general, you need _1.5x_ the bitrate or even more to get
same quality with cbr, i.e. vbr mp3 averaging 128 kbit/sec will be
about as good as 192 kbit cbr, maybe better. with vorbis i think the
difference is even more extreme.

and afaik vorbis cbr isn't even true cbr. it's just abr with a very
small window.

> > .ogm is a very bad format. 
> 
> What's so bad about ogm? I have to admit, I don't know much about 
> container formats (I hadn't even heard about mkv and nut before), but 
> what I read about ogm a while back sounded good (multiple audio streams, 
> error tolerant, streaming support). Does it have any downsides?

multiple audio streams: true
error tolerant: lie
streaming support: can be used for streaming, but very bad for it

other downsides:
massive overhead: more than avi, and it doesn't even have an index!
bad timestamp format: makes seeking troublesome
bad metadata format: you can't tell the language of a stream until you
start reading it so -alang won't work.
ms-centric headers: bleh

there are plenty of others i'm forgetting right now too. read the
mailing list archives if you care to know. basically ogm just sucks.
the only advantages it has over avi are the ability to store vorbis
audio, and multi-streams (actually avi can store multiple audio
streams and sub streams too, but very few players support it).

rich