[Theora] Testing libtheora-1.0alpha5

zikzak at tele2.fr zikzak at tele2.fr
Wed Aug 24 11:46:42 PDT 2005

On Mon, 22 Aug 2005 23:46:26 -0400
marco <marco at math.toronto.edu> wrote:

> Hi,
> I sent the message below a couple of months ago but I got
> no reply. Now that there's more activity perhaps someone
> could kindly provide me some guidance. Theora is great
> and the developers are doing a wonderful job, so I'd like to
> implement the codec in a way which does it justice...
> Original post:
> I wrote a plugin to enable LiVES (a video editor) to encode
> theora/vorbis/ogg files. I'm looking for some advice towards
> improving quality. If someone would like to help me
> test this please note that you'll need MPlayer, ImageMagick,
> sox, the encoder_example from libtheora (somewhere in the PATH),
> and Python 2.3.0 (this is fairly all standard stuff).
> Consider the following clip:
> http://lives.reimeika.ca/cvs/swath.ogg
> As you can see there are a lot of obvious artifacts. I generate
> this movie using a series on PNG images and the following command
> sequence:
> mkfifo -m 0600 stream.yuv
> mplayer mf://*.png -mf type=png:fps=29.97002997 -vf dsize=16:9,hqdn3d
> -vo yuv4mpeg -ao null -nosound & encoder_example -s 8 -S 7 -f 30000
> -F 1001 -v 10 -a 10 -o swath.ogg stream.yuv
> Any suggestions on how to improve this? In order to test I'm
> making available the LiVES video file (which is essentially a .tgz of
> the PNG images):
> http://lives.reimeika.ca/cvs/swath.lv1


I use the following lines to encode your png :

mkfifo -m 0600 stream.yuv
mplayer mf://*.png -mf type=png:fps=25 -quiet -vf
pp=va:128:8/ha:128:8/dr,smartblur=5:-0.2:30 -vo yuv4mpeg -ao null
-nosound & /home/seb/libtheora-1.0alpha5/examples/encoder_example -v 10
-a -1 -o swath.2.ogg stream.yuv

the -0.2 in smartblur is useful to 'hide' the block in the output
video, you can decrease the value and see the difference.

The result is available here :


More information about the Theora mailing list