[theora] FFMPEG2THEORA 0.26 / BIG Theora testing / BUG in players or Lib

Gregory Maxwell gmaxwell at gmail.com
Mon Feb 22 05:14:39 PST 2010

On Mon, Feb 22, 2010 at 5:21 AM, dos386 <dos386 at gmail.com> wrote:
> I tested the new FFMPEG2THEORA 0.26 and some players.
> 1. Biggest bug:
> http://freefile.kristopherw.us/uploads/temp/push5tru.zi7
> encodes into
> http://freefile.kristopherw.us/uploads/temp/push5tru.ogv
> the problem: it doesn't play well. MPLAYER reacts very badly, reports
> "invalid frames" and HANGS (known issue ???). But in VLC there is also
> a problem, less severe:

It plays fine for me in mplayer, totem.  VLC the has known issues
maintaining timing.

> http://freefile.kristopherw.us/uploads/temp/bugyhand.png
> (see shot, bad colours, +1 bug of VLC) - the hand moves to the right

No tool gives those crazy colors for me. Does VLC do that for other
files for you? It may be an issue specific to your display

> but there is a "relict" in the middle. The original file has also a "relict"
> there but much smaller. FireFOX apparently plays this well.

Thats not a 'bug'.  The encoder has decided that correcting that isn't
worth the bits.  It's a poor decision made more likely because of the
poor decision by some earlier lossy encoder in the chain.   The
development version of libtheora is much better at avoiding droppings.

> 2. VLC 1.0.5 bugs (I don't like this player, sorry)
> * See 1. - maybe VLC bug
> * Duration of OGG files still not fixed (WtF at 1.0.5 ...)
> * Very bad sound from Vorbis codec (not from other codecs)

I'd not heard of that. Can you provide more information?

Are you talking about *encode*. If you're talking about encode then
VLC may be using ffvorbis on your system.

The current development version of VLC fixed an issue where many
Theora videos would be blurry, but unfortunately it totally broke
offset handling. Hopefully this is fixed before the next release.

> 3. FFMPEG2THEORA issues:
> * silently overwrites existing output file (not bug, but bad behavior)

Thats how virtually all command line tools work.  Suddenly
interactively prompting you for a command which is not normally
interactive is also bad behaviour.

> 6. MPLAYER bugs:
> * "offset" is ignored (well known)
> * "nonstandard" subsamplings not supported, looks strange (well known)
> * See 1. - behaves very badly, hangs, looses frames (?)

A patch to fix 4:2:2 and 4:4:4 was recently accepted onto the mplayer
development tree.

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