[gst-devel] dc1394 : slow framerate and bayer

[Jan Schmidt]

Samuel Vinson wrote:
> Hi,
> 
> I use dc1394 plugin on windows XP (with libdc1394 patch 
> [https://sourceforge.net/tracker/index.php?func=detail&aid=1727980&group_id=8157&atid=308157])
> with avt guppy f033C.
> 
> I have two questions :
> 
> 1 .Plugin works nearly fine, but I obtain one frame /sec  with the 
> following pipeline :
> dc1394src ! ffmpegcolorspace ! directdrawsink.
> The messages give a framerate of 60/1. When I use only libdc1394 I have 
> a best framerate.
> Do you have an idea to obtain a framerate better than it ?

The frames are probably being dropped in the sink because they arrive 
too late. To avoid that the, dc1394src element should provide a clock, 
which it currently doesn't.

As a workaround, turn off sync in the directdrawsink, and you should 
probably add a queue for decoupling the input/output too:

gst-launch dc1394src ! queue ! ffmpegcolorspace ! directdrawsink sync=false

> 2. The guppy cameras use bayer algorithm to transmit the video.
> How make debayer the video ?

There is a bayer2rgb element that was recently added to gst-plugins-bad, 
but it will require some extra work on dc1394src for it know that the 
frames are bayer format and mark the buffers accordingly. Without that, 
the src element can't link to the bayer2rgb element, because the caps 
won't match.

J.