Adjusting the videorate for an mjpeg stream

[Severin Kacianka]

On 11/13/2013 10:10 PM, Sebastian Dröge wrote:
> On Mi, 2013-11-13 at 16:33 +0400, Andrey Nikitin wrote:
>> This list (VIDIOC_ENUM_FMT) does not have your "30/10" fps, 5,
>> 7.5, 10, 15, 20, 24 and 30 fps only.
> 
> And the problem in the pipeline is probably that videorate proxies
> the 30/20 framerate to the source, and that fails to configure that
> rate. Try adding a supported framerate on the first capsfilter.

I am currently not physically next to the camera (so I can't wave my
hand in front of it to see the FPS change :)), but I can confirm that
these rate do work. Thank you - I was not aware that the rates I can
set are directly related to the camera. I was under the impression
that I could use videorate to set any framerate I like and that
videorate would simply drop/duplicate frames as necessary to meet the
target.

I also noticed something else: I use iftop to get a rough idea of how
much bandwidth the stream uses. So when I halve the framerate I would
expect the bandwidth to roughly halve as well. However in my case the
bandwidth stays more or less the same.
Is there an explanation for that?

Thank you,
Severin