the rate of camera capture

[hz nan <nh...@gmail.com>]

Hi,all
In Linux, the rate of camera capture is different for diffrent camera.For
Logitech,
it need 120ms to capture one frame, it means that it can only capture 8
frames
one second. But for a good camera, it can capture 18-22frame one second.The
time is not used in the ffmpeg but used in the system function "iotcl" equate
with
camera read. Because opencvalso use V4L, so the opencv speed is also improve
 use good camera.
And because in Linux, system can't reopen camera,  I can't use multithread
to improve the capture rate.

nan hongzhen

Re: the rate of camera capture

[郑炎 <zy...@gmail.com>]

So if we use a good camera, the problem can be solved??


2011/7/14 hz nan <nh...@gmail.com>

> Hi,all
> In Linux, the rate of camera capture is different for diffrent camera.For
> Logitech,
> it need 120ms to capture one frame, it means that it can only capture 8
> frames
> one second. But for a good camera, it can capture 18-22frame one second.The
> time is not used in the ffmpeg but used in the system function "iotcl"
> equate
> with
> camera read. Because opencvalso use V4L, so the opencv speed is also
> improve
>  use good camera.
> And because in Linux, system can't reopen camera,  I can't use multithread
> to improve the capture rate.
>
> nan hongzhen
>



-- 
郑炎

Re: the rate of camera capture

[wang jun <ke...@gmail.com>]

Maybe that‘s the main reason troubling you for rather a long time.
As Zhang said,18-22 frame per second is enough for us to use.
That's really a good news for us all.

2011/7/14 hz nan <nh...@gmail.com>

> Hi,all
> In Linux, the rate of camera capture is different for diffrent camera.For
> Logitech,
> it need 120ms to capture one frame, it means that it can only capture 8
> frames
> one second. But for a good camera, it can capture 18-22frame one second.The
> time is not used in the ffmpeg but used in the system function "iotcl"
> equate
> with
> camera read. Because opencvalso use V4L, so the opencv speed is also
> improve
>  use good camera.
> And because in Linux, system can't reopen camera,  I can't use multithread
> to improve the capture rate.
>
> nan hongzhen
>



-- 
*If the dream is big enough,the facts don't count.*