From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751902AbaC1QS1 (ORCPT ); Fri, 28 Mar 2014 12:18:27 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:36232 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751680AbaC1QSS (ORCPT ); Fri, 28 Mar 2014 12:18:18 -0400 From: Laurent Pinchart To: Olivier Langlois Cc: m.chehab@samsung.com, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Stable Subject: Re: [PATCH] [media] uvcvideo: Fix clock param realtime setting Date: Fri, 28 Mar 2014 17:20:13 +0100 Message-ID: <16236471.uFSjvbT2di@avalon> User-Agent: KMail/4.11.5 (Linux/3.12.13-gentoo; KDE/4.11.5; x86_64; ; ) In-Reply-To: <1395985358-17047-1-git-send-email-olivier@trillion01.com> References: <1395985358-17047-1-git-send-email-olivier@trillion01.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Olivier, Thank you for the patch. On Friday 28 March 2014 01:42:38 Olivier Langlois wrote: > timestamps in v4l2 buffers returned to userspace are updated in > uvc_video_clock_update() which uses timestamps fetched from > uvc_video_clock_decode() by calling unconditionally ktime_get_ts(). > > Hence setting the module clock param to realtime have no effect > before this patch. > > This has been tested with ffmpeg: > > ffmpeg -y -f v4l2 -input_format yuyv422 -video_size 640x480 -framerate 30 -i > /dev/video0 \ -f alsa -acodec pcm_s16le -ar 16000 -ac 1 -i default \ > -c:v libx264 -preset ultrafast \ > -c:a libfdk_aac \ > out.mkv > > and inspecting the v4l2 input starting timestamp. > > Signed-off-by: Olivier Langlois > Cc: Stable Before applying this, I'm curious, do you have a use case for realtime time stamps ? > --- > drivers/media/usb/uvc/uvc_video.c | 15 ++++++++++----- > 1 file changed, 10 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c > b/drivers/media/usb/uvc/uvc_video.c index 898c208..c79db33 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -361,6 +361,14 @@ static int uvc_commit_video(struct uvc_streaming > *stream, * Clocks and timestamps > */ > > +static inline void uvc_video_get_ts(struct timespec *ts) > +{ > + if (uvc_clock_param == CLOCK_MONOTONIC) > + ktime_get_ts(ts); > + else > + ktime_get_real_ts(ts); > +} > + > static void > uvc_video_clock_decode(struct uvc_streaming *stream, struct uvc_buffer > *buf, const __u8 *data, int len) > @@ -420,7 +428,7 @@ uvc_video_clock_decode(struct uvc_streaming *stream, > struct uvc_buffer *buf, stream->clock.last_sof = dev_sof; > > host_sof = usb_get_current_frame_number(stream->dev->udev); > - ktime_get_ts(&ts); > + uvc_video_get_ts(&ts); > > /* The UVC specification allows device implementations that can't obtain > * the USB frame number to keep their own frame counters as long as they > @@ -1011,10 +1019,7 @@ static int uvc_video_decode_start(struct > uvc_streaming *stream, > return -ENODATA; > } > > - if (uvc_clock_param == CLOCK_MONOTONIC) > - ktime_get_ts(&ts); > - else > - ktime_get_real_ts(&ts); > + uvc_video_get_ts(&ts); > > buf->buf.v4l2_buf.sequence = stream->sequence; > buf->buf.v4l2_buf.timestamp.tv_sec = ts.tv_sec; -- Regards, Laurent Pinchart