diff options
authorOlivier Langlois <olivier@trillion01.com>2014-03-28 05:42:38 (GMT)
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2014-05-09 12:10:37 (GMT)
commit4d576e85f1d7e11190652619156b9a136d4c4a98 (patch)
parent780fa424e385f3459dc6baefdfc594b794e4effe (diff)
uvcvideo: Fix clock param realtime settinguvcvideo-next
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 has 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. Cc: Stable <stable@vger.kernel.org> Signed-off-by: Olivier Langlois <olivier@trillion01.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
1 files changed, 10 insertions, 5 deletions
diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c
index ca205ee..9144a2f 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;

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