[ogg-dev] [theora] XiphQT pre-release builds

Arek Korbik arkadini at gmail.com
Tue Jun 9 01:23:15 PDT 2009


Hi,

On Mon, Jun 8, 2009 at 4:28 PM, Silvia
Pfeiffer<silviapfeiffer1 at gmail.com> wrote:
>
> 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.

There was an, umm, ekhm, fixed buffer of 64kB in the TheoraDecoder and
buffer resizing wasn't implemented... So, if an encoded frame was
larger than the buffer it would skip it without decoding. I believe
you experienced the effects of that.

I fixed that and increased some values that could be responsible for
the a/v desync in HD content, although that issue I couldn't reproduce
myself. I would be great if you could test the new version and see if
the a/v stays in sync.

>
>> 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.

Definitely yes. I've built a new set of binaries (those are actually
0.1.9rc1 now):

http://people.xiph.org/~arek/

0.1.9 shapes up to be a proper release with non-empty changelog, after
all. But let's see if we can find even more smallish issues that will
be possible to fix quickly before final 0.1.9! :)

Thanks a lot,
Arek


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