Re: résolution webcam

On 23/02/16 18:47, Bret Busby wrote:
> On 23/02/2016, adhesionlistedediffusion
> <[email protected]> wrote:
>> Hello,
>>
>> Sorry, here is the translation : in the video options of Ekiga, my
>> webcam is limited to 704x576, but in the software "cheese" it can reach
>> 1920x1080.
>> How can I have a better resolution with Ekiga ?
>> Debian 8, Ekiga 4.0.1, et webcam Logitech C930e.
>>
>> Thanks
>>
>> JL
>
> Hello.
>
> This is not an answer to your question, but, rather, a question of
> your question.
>
> I have a Logitech webcam thing that shows as having 720p (1280x720?)
> capability, but, with the computer or the broadband limitations, or
> both, I find that I have to use it at a lesser resolution (640x480, I
> think, or, less), to get some sort of fluidity and realtime movement,
> otherwise, I get lagging and a series of still frames and jerkiness,
> rather than fluid motion.

I would say that using a very high resolution is better, but you need 
both a good camera (which is not your case it seems) and a relatively 
fast network.  I made some tests with 640x480 video and H264 if I 
remember correctly, and it tool around 50 kB/s, i.e. 400 kb/s.  If you 
use a 4 times video resolution (h*2, v*2), this yields very 
approximately 1.6 Mb/s in *upload*.

Best regards,
Eugen

>>From what I understand, (and, I am quite probably wrong), the higher
> resolutions are not good, for applications like Ekiga and Skype.
>
> I have just used cheese to record a video, with my Logitech webcam,
> and vlc showed the resolution to be 1280x960, and the motion was jerky
> and not fluid.
>
> I do not know what hardware, you have, or, what your data transmission
> rates are like, but this computer that I am using, has an i3 CPU, and,
> I think, an nVIDIA graphics thing with about 512MB of RAM (on the
> graphics thing - the computer has, I think, 16GB of RAM), and I have
> found that webcam resolution of more than 640x480, is too much for
> getting useful video.
>
> So, I am wondering whether it is worth you trying to get the high
> resolution of your webcam capability (1920x1080), for video, if the
> video processing, would not give you fluid motion for that resolution.
>
> You may have hardware, and, data transmission rates, that can
> accommodate the high resolution capability of your webcam, and give
> you a sufficient fps, to attain adequate fluidity of motion - I do not
> know.
>
> At this stage, I have not yet, been able to effect a successful video
> call with Ekiga - I have only been able to effect successful video
> calls, with skype.
>