video broken on 1.75?

[John Watlington]

When using a block transform based video codec (MPEG-1/2/4, H.263/4, etc)
the dimensions of the video being encoded/decoded should always be a multiple
of the block size (8x8 in the above cases, although for MPEG 16x16 should be
used.)  To do otherwise requires serious contortions of the codec and doesn't
reduce the processing load.  I'm not at all surprised that a hardware
encoder/decoder would just fail.

Cheers,
wad

On Mar 19, 2013, at 3:37 PM, Daniel Drake wrote:

> On Mon, Mar 18, 2013 at 7:37 PM, Sameer Verma <sverma at sfsu.edu> wrote:
>> We have a bunch of XO 1.75 going to Madagascar. These have build
>> 13.1.0 (candidate 35). This ogv file [1] works well on a XO-1 but does
>> not play via jukebox. The ogv file plays well in Browse (trouble with
>> going fullscreen). It plays ok for a few seconds via MediaPlayer in
>> GNOME.
>> 
>> [1] http://verma.sfsu.edu/projects/olpc/sample-for-xo.ogv
> 
> Thanks for reporting.
> Unfortunately there are many ogg theora files that don't play back on
> XO-1.75, but they normally fail with an error message:
> http://dev.laptop.org/ticket/12004
> 
> So I filed a new ticket for this video: http://dev.laptop.org/ticket/12634
> 
> The reason that it works in Browse is probably that it is not using
> hardware accelerated playback there.
> 
> When I saw a case of #12004 before, I worked around it by re-encoding
> the video as it had some slightly special parameters. This video would
> appear to be similar. It is a 320x180 video somehow encoded into the
> 320x192 theora resolution. I suspect if you re-encode it so that both
> measurements are equal, it will work OK.
> 
> Daniel
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