[FFmpeg-devel] PATCH grab.c, adding support for hardware based VIDIOSFPS

[mmh]

Benoit Fouet writes:
 > mmh wrote:
 > > Benoit Fouet writes:
 > >  > Hi,
 > >  > 
 > >  > mmh wrote:
 > >
 > > I don't think we need to change my original patch.
 > >
 > > the drivers default behavior is to return an error ie negative value
 > > if its not supported in the switch (cmd) { case blah1: .... in the video 4
 > > linux stack.
 > >   
 > 
 > this is wrong.
 > from my videodev2.h:
 > #define VIDIOC_S_RDS            _IOWR ('V', BASE_VIDIOC_PRIVATE+11,
 > struct v4l2_radio_rds_set)
 > 
 > i can (if i want) change the BASE_VIDIOC_PRIVATE+11 by
 > BASE_VIDIOC_PRIVATE+20
 > this ioctl will be defined, but will not do what you want...
 > 
 > moreover, it can just return without any error, and lead you to believe
 > that framerate is accepted by the camera, even though this is not true...

Ben,

I see it, the thing can have various meanings based on platform, So I
guess if I remove this from the grab.c implementation.

#ifndef VIDIOSFPS
#define VIDIOSFPS		_IOW('v',BASE_VIDIOCPRIVATE+20, int)			/* Set fps */
#endif


And then if the VIDIOSFPS is defined by the system v4l includes it
would be acceptable to do this?

    fps = s->frame_rate / s->frame_rate_base;
    s->sw_fps_reduction  = 1;
#ifdef VIDIOSFPS
    s->sw_fps_reduction  = ioctl( video_fd, VIDIOSFPS, &fps ) < 0;
#endif


Thanks for struggling through this issue with me.

Marc