theora dev - May 2010 - idct8x8 C version in libtheora1.1 release

When using the IDCT routines, the C version [ lib/idct.c:
oc_idct8x8_c(ogg_int16_t _y[64],int _last_zzi)] in libtheora 1.1.1, the
decoded image is garbled. Is it functionally equivalent to the MMX optimized
version [lib/x86/mmxidct.c: oc_idct8x8_mmx(ogg_int16_t _y[64],int
_last_zzi)] ?

I used some of the Theora video files from here:
http://wiki.xiph.org/index.php/List_of_Theora_videos for testing with
firefox browser. For testing purposes, I called the C version of IDCT
routine instead of the MMX optimized version. Is there any documentation on
the IDCT algorithm used in Theora library?

thanks,
- mouli
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/theora-dev/attachments/20100518/c7b0351f/attachment.htm

On Tue, 18 May 2010 09:41:36 -0700, chandramouli narayanan
<nc.n.mouli at gmail.com> wrote:
> When using the IDCT routines, the C version [ lib/idct.c:
> oc_idct8x8_c(ogg_int16_t _y[64],int _last_zzi)] in libtheora 1.1.1, the
> decoded image is garbled. Is it functionally equivalent to the MMX
> optimized
> version [lib/x86/mmxidct.c: oc_idct8x8_mmx(ogg_int16_t _y[64],int
> _last_zzi)] ?
> 
> I used some of the Theora video files from here:
> http://wiki.xiph.org/index.php/List_of_Theora_videos for testing with
> firefox browser. For testing purposes, I called the C version of IDCT
> routine instead of the MMX optimized version. Is there any documentation
on
> the IDCT algorithm used in Theora library?
I downloaded a fresh copy of the 1.1.1 tarball from
http://svn.xiph.org/releases/theora/libtheora-1.1.1.tar.bz2 on x86-32, ran
./configure --disable-asm and make, and used player_example to view
http://serv2.internautas.tv/videos/ogg/20100518_1.ogg, and didn't see any
garbling of the image. I also confirmed that it was, in fact, calling
oc_idct8x8_c(), and checked that dump_video produces the correct md5sum for
some of my personal test videos.

The exact iDCT algorithm is thouroughly documented in Section 7.9.3 of the
Theora specification: http://www.theora.org/doc/Theora.pdf

On Tue, May 18, 2010 at 3:44 PM, Ralph Giles <giles at thaumas.net> wrote:
> On 18 May 2010 15:37, chandramouli narayanan <nc.n.mouli at
gmail.com> wrote:
>
> > --------------- error when running with player_example
> > examples/player_example ~/Downloads/1696_lightnings.ogg
> > [...]
> > Could not open audio device /dev/dsp.
>
> This means that another program is holding exclusive write access to
> your audio device. If you have another audio application open, such as
> a music player, try quitting that first. However, on recent systems
> this is often the pulseaudio daemon, so you may need to temporarily
> disable that for player_example to work with audio.
>
> If you're just interested in testing video playback, you can use the
> oggz-rip utility to strip out the audio track.
>
>  -r
>
My issue had to do with no /dev/dsp. I've reconfigured Linux kernel with
deprecated OSS support and loaded the module snd-pcm-oss and that created
/dev/dsp. Now, I can use the example_player.

thanks
- mouli
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
http://lists.xiph.org/pipermail/theora-dev/attachments/20100518/4fa251ed/attachment.htm