From: Sergey Senozhatsky <senozhatsky@chromium.org>
To: Ricardo Ribalda <ribalda@chromium.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
linux-kernel@vger.kernel.org, "hn.chen" <hn.chen@sunplusit.com>,
linux-media@vger.kernel.org
Subject: Re: [PATCH v9 6/6] media: uvcvideo: Fix hw timestamp handling for slow FPS
Date: Thu, 16 Mar 2023 12:07:55 +0900 [thread overview]
Message-ID: <20230316030755.GC1927922@google.com> (raw)
In-Reply-To: <20220920-resend-hwtimestamp-v9-6-55a89f46f6be@chromium.org>
On (23/03/15 14:30), Ricardo Ribalda wrote:
> In UVC 1.5 we get a single clock value per frame. With the current
> buffer size of 32, FPS slowers than 32 might roll-over twice.
>
> The current code cannot handle two roll-over and provide invalid
> timestamps.
>
> Revome all the samples from the circular buffer that are more than two
> rollovers old, so the algorithm always provides good timestamps.
>
> Note that we are removing values that are more than one second old,
> which means that there is enough distance between the two points that
> we use for the interpolation to provide good values.
>
> Tested-by: HungNien Chen <hn.chen@sunplusit.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
[..]
> + if (clock->count > 0 && clock->last_sof > sample->dev_sof) {
> + /*
> + * Remove data from the circular buffer that is older than the
> + * last overflow. We only support one overflow per circular
> + * buffer.
> + */
> + if (clock->last_sof_overflow != -1) {
> + clock->count = (clock->head - clock->last_sof_overflow
> + + clock->count) % clock->count;
A minor nit: there is a tab between `clock->count)` and `% clock->count` :)
next prev parent reply other threads:[~2023-03-16 3:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-15 13:30 [PATCH v9 0/6] uvcvideo: Fixes for hw timestamping Ricardo Ribalda
2023-03-15 13:30 ` [PATCH v9 1/6] media: uvcvideo: Fix negative modulus calculation Ricardo Ribalda
2023-03-16 3:05 ` Sergey Senozhatsky
2024-02-12 22:59 ` Laurent Pinchart
2024-02-19 10:28 ` Ricardo Ribalda
2024-02-19 10:40 ` Laurent Pinchart
2024-02-19 15:07 ` Ricardo Ribalda
2024-03-21 21:50 ` Laurent Pinchart
2024-03-22 9:19 ` Laurent Pinchart
2024-03-22 9:29 ` Ricardo Ribalda
2024-03-22 9:35 ` Laurent Pinchart
2023-03-15 13:30 ` [PATCH v9 2/6] media: uvcvideo: Ignore empty TS packets Ricardo Ribalda
2024-03-21 23:26 ` Laurent Pinchart
2024-03-22 8:22 ` Ricardo Ribalda
2024-03-22 8:52 ` Laurent Pinchart
2023-03-15 13:30 ` [PATCH v9 3/6] media: uvcvideo: Quirk for invalid dev_sof in Logitech C922 Ricardo Ribalda
2024-03-21 23:44 ` Laurent Pinchart
2024-03-22 8:32 ` Ricardo Ribalda
2024-03-22 8:52 ` Laurent Pinchart
2023-03-15 13:30 ` [PATCH v9 4/6] media: uvcvideo: Allow hw clock updates with buffers not full Ricardo Ribalda
2023-03-16 3:08 ` Sergey Senozhatsky
2024-03-22 0:12 ` Laurent Pinchart
2023-03-15 13:30 ` [PATCH v9 5/6] media: uvcvideo: Refactor clock circular buffer Ricardo Ribalda
2024-03-22 0:36 ` Laurent Pinchart
2023-03-15 13:30 ` [PATCH v9 6/6] media: uvcvideo: Fix hw timestamp handling for slow FPS Ricardo Ribalda
2023-03-16 3:07 ` Sergey Senozhatsky [this message]
2024-03-22 9:35 ` Laurent Pinchart
2024-03-22 9:53 ` Ricardo Ribalda
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230316030755.GC1927922@google.com \
--to=senozhatsky@chromium.org \
--cc=hn.chen@sunplusit.com \
--cc=laurent.pinchart@ideasonboard.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-media@vger.kernel.org \
--cc=mchehab@kernel.org \
--cc=ribalda@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).