| Message ID | 20121022172901.GA24720@tugrik.mns.mnsspb.ru (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon October 22 2012 19:29:01 Kirill Smelkov wrote: > On Mon, Oct 22, 2012 at 09:01:39PM +0400, Kirill Smelkov wrote: > > On Mon, Oct 22, 2012 at 04:16:14PM +0200, Hans Verkuil wrote: > > > On Mon October 22 2012 15:54:44 Kirill Smelkov wrote: > > > > I was testing my video-over-ethernet subsystem today, and vivi seemed to > > > > be perfect video source for testing when one don't have lots of capture > > > > boards and cameras. Only its framerate was hardcoded to NTSC's 30fps, > > > > while in my country we usually use PAL (25 fps). That's why the patch. > > > > Thanks. > > > > > > Rather than introducing a module option, it's much nicer if you can > > > implement enum_frameintervals and g/s_parm. This can be made quite flexible > > > allowing you to also support 50/59.94/60 fps. > > > > Thanks for feedback. I've reworked the patch for FPS to be set via > > ->{g,s}_parm(), and yes now it is more flexble, because one can set > > By the way, here is what I've found while working on the abovementioned > patch: > > ---- 8< ---- > From: Kirill Smelkov <kirr@mns.spb.ru> > Date: Mon, 22 Oct 2012 21:14:01 +0400 > Subject: [PATCH] v4l2: Fix typo in struct v4l2_captureparm description > > Judging from what drivers do and from my experience temeperframe > fraction is set in seconds - look e.g. here > > static int bttv_g_parm(struct file *file, void *f, > struct v4l2_streamparm *parm) > { > struct bttv_fh *fh = f; > struct bttv *btv = fh->btv; > > v4l2_video_std_frame_period(bttv_tvnorms[btv->tvnorm].v4l2_id, > &parm->parm.capture.timeperframe); > > ... > > void v4l2_video_std_frame_period(int id, struct v4l2_fract *frameperiod) > { > if (id & V4L2_STD_525_60) { > frameperiod->numerator = 1001; > frameperiod->denominator = 30000; > } else { > frameperiod->numerator = 1; > frameperiod->denominator = 25; > } > > and also v4l2-ctl in userspace decodes this as seconds: > > if (doioctl(fd, VIDIOC_G_PARM, &parm, "VIDIOC_G_PARM") == 0) { > const struct v4l2_fract &tf = parm.parm.capture.timeperframe; > > ... > > printf("\tFrames per second: %.3f (%d/%d)\n", > (1.0 * tf.denominator) / tf.numerator, > tf.denominator, tf.numerator); > > The typo was there from day 1 - added in 2002 in e028b61b ([PATCH] > add v4l2 api)(*) > > (*) found in history tree > git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git > > Signed-off-by: Kirill Smelkov <kirr@mns.spb.ru> Good catch. Luckily the V4L2 spec is correct, it is just that single comment that's wrong. Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Thanks! Hans > --- > include/uapi/linux/videodev2.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index 57bfa59..2fff7ff 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -726,29 +726,29 @@ struct v4l2_window { > __u32 field; /* enum v4l2_field */ > __u32 chromakey; > struct v4l2_clip __user *clips; > __u32 clipcount; > void __user *bitmap; > __u8 global_alpha; > }; > > /* > * C A P T U R E P A R A M E T E R S > */ > struct v4l2_captureparm { > __u32 capability; /* Supported modes */ > __u32 capturemode; /* Current mode */ > - struct v4l2_fract timeperframe; /* Time per frame in .1us units */ > + struct v4l2_fract timeperframe; /* Time per frame in seconds */ > __u32 extendedmode; /* Driver-specific extensions */ > __u32 readbuffers; /* # of buffers for read */ > __u32 reserved[4]; > }; > > /* Flags for 'capability' and 'capturemode' fields */ > #define V4L2_MODE_HIGHQUALITY 0x0001 /* High quality imaging mode */ > #define V4L2_CAP_TIMEPERFRAME 0x1000 /* timeperframe field is supported */ > > struct v4l2_outputparm { > __u32 capability; /* Supported modes */ > __u32 outputmode; /* Current mode */ > struct v4l2_fract timeperframe; /* Time per frame in seconds */ > __u32 extendedmode; /* Driver-specific extensions */ > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 57bfa59..2fff7ff 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -726,29 +726,29 @@ struct v4l2_window { __u32 field; /* enum v4l2_field */ __u32 chromakey; struct v4l2_clip __user *clips; __u32 clipcount; void __user *bitmap; __u8 global_alpha; }; /* * C A P T U R E P A R A M E T E R S */ struct v4l2_captureparm { __u32 capability; /* Supported modes */ __u32 capturemode; /* Current mode */ - struct v4l2_fract timeperframe; /* Time per frame in .1us units */ + struct v4l2_fract timeperframe; /* Time per frame in seconds */ __u32 extendedmode; /* Driver-specific extensions */ __u32 readbuffers; /* # of buffers for read */ __u32 reserved[4]; }; /* Flags for 'capability' and 'capturemode' fields */ #define V4L2_MODE_HIGHQUALITY 0x0001 /* High quality imaging mode */ #define V4L2_CAP_TIMEPERFRAME 0x1000 /* timeperframe field is supported */ struct v4l2_outputparm { __u32 capability; /* Supported modes */ __u32 outputmode; /* Current mode */ struct v4l2_fract timeperframe; /* Time per frame in seconds */ __u32 extendedmode; /* Driver-specific extensions */