Hi,
please use "uvc_trace(UVC_TRACE_DESCR," or pr_debug instead of printk.
So you can enable verbosity only if you need.
On Di, 2011-06-07 at 17:56 +0200, Yann Sionneau wrote:
> Hi again,
>
> here is as attached file a new patch that applies to linux 2.6.39 tree
> (linux-2.6.git, tag v2.6.39).
>
> This patch now prints at the end of each stream :
>
> (*) total number of PTS (taking into account each packet)
> (*) total number of SCR
> (*) total number of ERR
> (*) number of packets without PTS (nb_missing_pts)
> (*) number of packets without SCR (nb_missing_scr)
>
> It will print as well for each packet (beware, it will hugely flood your
> syslog) :
>
> (*) SCR
> (*) diff with previous packet's SCR
> (*) PTS
> (*) diff with previous packet's PTS
>
> Beware, to see the "end of stream" statistics, you have to scroll up a
> little bit, it will be somewhere in the end of the per-packet
> information flood.
>
> Some results inline in the e-mail.
>
> On 06/06/2011 11:22 PM, Yann Sionneau wrote:
> > Le 06/06/11 19:42, Laurent Pinchart a écrit :
> >> Hi Yann,
> >>
> >> Thanks for the patch.
> >>
> >> On Friday 03 June 2011 15:48:59 Yann Sionneau wrote:
> >>> Hi Laurent and the UVC list,
> >>>
> >>> Here is a patch [snip]
> >> You should take all UVC packets into account, not just the first one for
> >> each
> >> frame.
> > Yes I don't know why in my head I thought only the first uvc packet
> > would have a header for the frame with timestamps and such, but it makes
> > no sense, each packet has its own header and the start of frame is just
> > signaled by the toggling of the FID :)
> >
> >> the important information are
> >>
> >> - do all frames have a PTS timestamp in their first packet ?
> > It seems so yes, at least on the two webcams I tried with the patch.
> >
> >> - do all non-empty packets for a frame have a PTS timestamp, and is it
> >> constant through the whole frame as it should be ?
> > Let's modify the patch to count the PTS and SCR of all packets instead
> > of only one per frame in order to sort this out !
> I tested with the Logitech HD Pro C910, all packets have a PTS.
> PTS are indeed constant through the whole frame as it should be.
> >> - how many SCR timestamps do we have per frame ? are they constant through
> >> the
> >> whole frame or do they vary as they should ?
> >>
> > Same here !
> With the same webcam, all packets have a SCR.
> The SCR value does vary through each frame, as it should do.
> The difference between the previous SCR is usually the same, except at a
> regular interval where there is a "jump" in SCR values.
>
> for example, SCR - SCR_prev would be 7 times the same difference, and
> then it will change for just one time, and then go back to the old
> difference for 7 times etc.
>
> >>> [snip]
> > Thanks for your review and comments, will submit a new patch ASAP !
--
Regards,
Alexey
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