| Message ID | 20220317104740.569310-3-umang.jain@ideasonboard.com |
|---|---|
| State | Accepted |
| Delegated to: | Umang Jain |
| Headers | show |
| Series |
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| Related | show |
Hi Umang, Thank you for the patch. On Thu, Mar 17, 2022 at 04:17:39PM +0530, Umang Jain via libcamera-devel wrote: > Add a comment to clarify why we set v4l2_buffer timestamp while > queuing the buffer (VIDIOC_QBUF). The timstamps are required to > be supplied for memory-to-memory devices for output streams which > then are copied to capture stream buffers with the help of > V4L2_BUF_FLAG_TIMESTAMP_COPY (set by the driver). > > Signed-off-by: Umang Jain <umang.jain@ideasonboard.com> > --- > src/libcamera/v4l2_videodevice.cpp | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp > index 5580269f..a6c54b19 100644 > --- a/src/libcamera/v4l2_videodevice.cpp > +++ b/src/libcamera/v4l2_videodevice.cpp > @@ -1600,6 +1600,14 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer) > buf.length = planes[0].length; > } > > + /* > + * Timestamps are to be supplied if the device is a mem-to-mem > + * device. The drivers will have V4L2_BUF_FLAG_TIMESTAMP_COPY > + * set hence these timestamps will be copied from the output > + * buffers to capture buffers. If the device is not mem-to-men, s/mem-to-men/mem-to-mem/ > + * there is no harm in setting the timestamps as they will be > + * ignored (and over-written). Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > + */ > buf.timestamp.tv_sec = metadata.timestamp / 1000000000; > buf.timestamp.tv_usec = (metadata.timestamp / 1000) % 1000000; > }
Quoting Laurent Pinchart via libcamera-devel (2022-03-23 00:13:59) > Hi Umang, > > Thank you for the patch. > > On Thu, Mar 17, 2022 at 04:17:39PM +0530, Umang Jain via libcamera-devel wrote: > > Add a comment to clarify why we set v4l2_buffer timestamp while > > queuing the buffer (VIDIOC_QBUF). The timstamps are required to > > be supplied for memory-to-memory devices for output streams which > > then are copied to capture stream buffers with the help of > > V4L2_BUF_FLAG_TIMESTAMP_COPY (set by the driver). > > > > Signed-off-by: Umang Jain <umang.jain@ideasonboard.com> > > --- > > src/libcamera/v4l2_videodevice.cpp | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp > > index 5580269f..a6c54b19 100644 > > --- a/src/libcamera/v4l2_videodevice.cpp > > +++ b/src/libcamera/v4l2_videodevice.cpp > > @@ -1600,6 +1600,14 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer) > > buf.length = planes[0].length; > > } > > > > + /* > > + * Timestamps are to be supplied if the device is a mem-to-mem > > + * device. The drivers will have V4L2_BUF_FLAG_TIMESTAMP_COPY > > + * set hence these timestamps will be copied from the output > > + * buffers to capture buffers. If the device is not mem-to-men, > > s/mem-to-men/mem-to-mem/ > > > + * there is no harm in setting the timestamps as they will be > > + * ignored (and over-written). > > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com> > > > + */ > > buf.timestamp.tv_sec = metadata.timestamp / 1000000000; > > buf.timestamp.tv_usec = (metadata.timestamp / 1000) % 1000000; > > } > > -- > Regards, > > Laurent Pinchart
diff --git a/src/libcamera/v4l2_videodevice.cpp b/src/libcamera/v4l2_videodevice.cpp index 5580269f..a6c54b19 100644 --- a/src/libcamera/v4l2_videodevice.cpp +++ b/src/libcamera/v4l2_videodevice.cpp @@ -1600,6 +1600,14 @@ int V4L2VideoDevice::queueBuffer(FrameBuffer *buffer) buf.length = planes[0].length; } + /* + * Timestamps are to be supplied if the device is a mem-to-mem + * device. The drivers will have V4L2_BUF_FLAG_TIMESTAMP_COPY + * set hence these timestamps will be copied from the output + * buffers to capture buffers. If the device is not mem-to-men, + * there is no harm in setting the timestamps as they will be + * ignored (and over-written). + */ buf.timestamp.tv_sec = metadata.timestamp / 1000000000; buf.timestamp.tv_usec = (metadata.timestamp / 1000) % 1000000; }
Add a comment to clarify why we set v4l2_buffer timestamp while queuing the buffer (VIDIOC_QBUF). The timstamps are required to be supplied for memory-to-memory devices for output streams which then are copied to capture stream buffers with the help of V4L2_BUF_FLAG_TIMESTAMP_COPY (set by the driver). Signed-off-by: Umang Jain <umang.jain@ideasonboard.com> --- src/libcamera/v4l2_videodevice.cpp | 8 ++++++++ 1 file changed, 8 insertions(+)