[theora] XiphQT pre-release builds

[Silvia Pfeiffer]

Hi Arek,

On Sat, Jun 6, 2009 at 11:00 PM, Arek Korbik<arkadini at gmail.com> wrote:
> On Sat, May 30, 2009 at 4:02 PM, Silvia
> Pfeiffer<silviapfeiffer1 at gmail.com> wrote:
>> I tried xiph-qt-20090529.dmg with a video exporting from iMovie and it
>> did really well. I run OS X 10.5.3. I played it back using vlc.
>> QuickTime player says it cannot open the ogg file "Operation could not
>> be completed. (OSStatus error -50.)".
>
> I tried both uninstalled and a clean install of xiph-qt-20090529.dmg
> and all the files I encoded are playable in QuickTime player. Does the
> error appear for all the encoded files? What about oggs not produced
> by OSX/QuickTime tools?

I just created another Ogg export from iMovie and it now plays in
QuickTime. Maybe there were some strange things still in memory or so
- I have since restarted my computer.

The playback in QuickTime however has some artifacts that vlc does not expose:

* a/v are out of sync
* there are green lines and a few red ones at the top and the bottom
of the picture
* there are sometimes artifacts from pervious pictures, such as a
remaining white spot
* overall the decode quality is pretty poor in comparison to vlc

I do wonder what creates these issues.

>> As for following latest code - I'm sure if you used the Thusnelda
>> improvements, the video quality would be better at lower bitrates.
>> Latest releases have bug fixes and new features, which it is good to
>> follow, in particular if security bugs were fixed.
>
> Following suggestions, I guess I should make 3 sets of binaries for the release:
>  - built with the latest stable releases of the Xiph libs (would be
> the default download option),
>  - built with HEADs of the trunks of the libs (what I used to do),
>  - built with HEADs + Thusnelda

I also think the first and the last would be good enough.

Thanks a lot for this effort! It's great to see Ogg Theora/Vorbis
become part of the normal toolchain of dealing with video!

Cheers,
Silvia.