Re: [Linphone-developers] isn't trying V4L2_PIX_FMT_YUYV before V4L2_PIX_FMT_MJPEG better?

[Alan Chen]

For me, I noticed that when I use YUYV, top shows linphonec is using
1% CPU and when I use MJPEG, linphonec is using 11-12%.

Maybe the difference is not that dramatic but I think converting pix
format is definitely much faster than decoding MJPEG.  And MJPEG is a
lossy format.

RGB should be ahead of MJPEG too.  I think.

-alan

On Tue, Dec 9, 2008 at 1:13 PM, Simon Morlat <address@hidden> wrote:
> Le Tuesday 09 December 2008 10:14:46 Alan Chen, vous avez écrit :
>> Hi all,
>>
>> In  mediastreamer2 msv4l2.c, I wonder if calling
>> v4lv2_try_format(s,V4L2_PIX_FMT_YUYV) before
>> v4lv2_try_format(s,V4L2_PIX_FMT_MJPEG) is better.  isn't decoding
>> MJPEG consuming more CPU and not as desirable?
> You are probably right.
> V4L2_PIX_FMT_YUYV pictures are bigger and then need to be converted to YUV420P
> for processing by the encoder.
> However I never noticed MJPEG was consuming CPU significatively (it does not
> increase the fan speed of my laptop, while resizing to full screen does).
> Did you make measures for the two options ?
>
> Simon
>