ogg dev - Aug 2010 - gstreamer oggmux and variable framerate

Hallo all,

I currently hacking on cheese an got problem with variable framerate
produced by webcams (2-30fps). There is no problem to encode it with
theora, but problem to mux it in ogg. Or at least to play produced file.
There is no problem tu mux it in to matroska.

My question is: should actually ogg support timestamps, also variable
framerate? If yes: it seems to be some where broken.


Here is what i use to reproduce my issue: gst-launch-0.10 -e pulsesrc !
queue ! audioconvert ! vorbisenc ! queue ! oggmux name="muxer" v4l2src
!
video/x-raw-yuv,width=320,height=240 ! ffmpegcolorspace ! theoraenc
keyframe-force=1 ! muxer. muxer. ! filesink location=foo.ogg

Regards,
	Alexey

Alexey Fisher wrote:
> My question is: should actually ogg support timestamps, also variable
> framerate? If yes: it seems to be some where broken.
The Ogg mapping for Theora is fixed-framerate. You can hack something 
into Ogg by using a higher framerate and inserting "duplicate frame" 
packets (which cost approximately one byte each, including the container 
overhead), but AFAIK there is no gstreamer support for doing this 
automatically.

On 08/19/2010 11:29 AM, Timothy B. Terriberry wrote:
> Alexey Fisher wrote:
>> My question is: should actually ogg support timestamps, also variable
>> framerate? If yes: it seems to be some where broken.
> 
> The Ogg mapping for Theora is fixed-framerate. You can hack something 
> into Ogg by using a higher framerate and inserting "duplicate
frame"
> packets (which cost approximately one byte each, including the container 
> overhead), but AFAIK there is no gstreamer support for doing this 
> automatically.
The best solution I know of is to use the "videorate" element to
convert
the stream into a form that theoraenc can handle:

http://www.gstreamer.net/data/doc/gstreamer/head/gst-plugins-base-plugins/html/gst-plugins-base-plugins-videorate.html

--Ben

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 198 bytes
Desc: OpenPGP digital signature
Url :
http://lists.xiph.org/pipermail/ogg-dev/attachments/20100819/5180318b/attachment.pgp