| Message ID | 1391813548-818-1-git-send-email-sakari.ailus@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 02/07/2014 11:52 PM, Sakari Ailus wrote: > Some devices do not produce timestamps that correspond to the end of the > frame. The user space should be informed on the matter. This patch achieves > that by adding buffer flags (and a mask) for timestamp sources since more > possible timestamping points are expected than just two. > > A three-bit mask is defined (V4L2_BUF_FLAG_TSTAMP_SRC_MASK) and two of the > eight possible values is are defined V4L2_BUF_FLAG_TSTAMP_SRC_EOF for end of > frame (value zero) V4L2_BUF_FLAG_TSTAMP_SRC_SOE for start of exposure (next > value). > > Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> I would prefer to split the uvc change into a separate patch. It doesn't really belong here. Regards, Hans > --- > since v4.1: > - Replace SOF flag by SOE flag > - Add mask for timestamp sources > > Documentation/DocBook/media/v4l/io.xml | 28 ++++++++++++++++++++++------ > drivers/media/usb/uvc/uvc_queue.c | 3 ++- > include/media/videobuf2-core.h | 2 ++ > include/uapi/linux/videodev2.h | 4 ++++ > 4 files changed, 30 insertions(+), 7 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > index 2c155cc..451626f 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -654,12 +654,6 @@ plane, are stored in struct <structname>v4l2_plane</structname> instead. > In that case, struct <structname>v4l2_buffer</structname> contains an array of > plane structures.</para> > > - <para>For timestamp types that are sampled from the system clock > -(V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC) it is guaranteed that the timestamp is > -taken after the complete frame has been received (or transmitted in > -case of video output devices). For other kinds of > -timestamps this may vary depending on the driver.</para> > - > <table frame="none" pgwide="1" id="v4l2-buffer"> > <title>struct <structname>v4l2_buffer</structname></title> > <tgroup cols="4"> > @@ -1120,6 +1114,28 @@ in which case caches have not been used.</entry> > <entry>The CAPTURE buffer timestamp has been taken from the > corresponding OUTPUT buffer. This flag applies only to mem2mem devices.</entry> > </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_MASK</constant></entry> > + <entry>0x00070000</entry> > + <entry>Mask for timestamp sources below. The timestamp source > + defines the point of time the timestamp is taken in relation to > + the frame. Logical and operation between the > + <structfield>flags</structfield> field and > + <constant>V4L2_BUF_FLAG_TSTAMP_SRC_MASK</constant> produces the > + value of the timestamp source.</entry> > + </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_EOF</constant></entry> > + <entry>0x00000000</entry> > + <entry>"End of frame." The buffer timestamp has been taken when > + the last pixel of the frame has been received.</entry> > + </row> > + <row> > + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_SOE</constant></entry> > + <entry>0x00010000</entry> > + <entry>"Start of exposure." The buffer timestamp has been taken > + when the exposure of the frame has begun.</entry> > + </row> > </tbody> > </tgroup> > </table> > diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c > index cd962be..a9292d2 100644 > --- a/drivers/media/usb/uvc/uvc_queue.c > +++ b/drivers/media/usb/uvc/uvc_queue.c > @@ -149,7 +149,8 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, > queue->queue.buf_struct_size = sizeof(struct uvc_buffer); > queue->queue.ops = &uvc_queue_qops; > queue->queue.mem_ops = &vb2_vmalloc_memops; > - queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; > + queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC > + | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; > ret = vb2_queue_init(&queue->queue); > if (ret) > return ret; > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index bef53ce..b6b992d 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h > @@ -312,6 +312,8 @@ struct v4l2_fh; > * @buf_struct_size: size of the driver-specific buffer structure; > * "0" indicates the driver doesn't want to use a custom buffer > * structure type, so sizeof(struct vb2_buffer) will is used > + * @timestamp_type: Timestamp flags; V4L2_BUF_FLAGS_TIMESTAMP_* and > + * V4L2_BUF_FLAGS_TSTAMP_SRC_* > * @gfp_flags: additional gfp flags used when allocating the buffers. > * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 > * to force the buffer allocation to a specific memory zone. > diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h > index e9ee444..82e8661 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -695,6 +695,10 @@ struct v4l2_buffer { > #define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x00000000 > #define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x00002000 > #define V4L2_BUF_FLAG_TIMESTAMP_COPY 0x00004000 > +/* Timestamp sources. */ > +#define V4L2_BUF_FLAG_TSTAMP_SRC_MASK 0x00070000 > +#define V4L2_BUF_FLAG_TSTAMP_SRC_EOF 0x00000000 > +#define V4L2_BUF_FLAG_TSTAMP_SRC_SOE 0x00010000 > > /** > * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor > -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hans Verkuil wrote: > On 02/07/2014 11:52 PM, Sakari Ailus wrote: >> Some devices do not produce timestamps that correspond to the end of the >> frame. The user space should be informed on the matter. This patch achieves >> that by adding buffer flags (and a mask) for timestamp sources since more >> possible timestamping points are expected than just two. >> >> A three-bit mask is defined (V4L2_BUF_FLAG_TSTAMP_SRC_MASK) and two of the >> eight possible values is are defined V4L2_BUF_FLAG_TSTAMP_SRC_EOF for end of >> frame (value zero) V4L2_BUF_FLAG_TSTAMP_SRC_SOE for start of exposure (next >> value). >> >> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> > > I would prefer to split the uvc change into a separate patch. It doesn't really > belong here. Fine for me. I'll take that into account in the next version.
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 2c155cc..451626f 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -654,12 +654,6 @@ plane, are stored in struct <structname>v4l2_plane</structname> instead. In that case, struct <structname>v4l2_buffer</structname> contains an array of plane structures.</para> - <para>For timestamp types that are sampled from the system clock -(V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC) it is guaranteed that the timestamp is -taken after the complete frame has been received (or transmitted in -case of video output devices). For other kinds of -timestamps this may vary depending on the driver.</para> - <table frame="none" pgwide="1" id="v4l2-buffer"> <title>struct <structname>v4l2_buffer</structname></title> <tgroup cols="4"> @@ -1120,6 +1114,28 @@ in which case caches have not been used.</entry> <entry>The CAPTURE buffer timestamp has been taken from the corresponding OUTPUT buffer. This flag applies only to mem2mem devices.</entry> </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_MASK</constant></entry> + <entry>0x00070000</entry> + <entry>Mask for timestamp sources below. The timestamp source + defines the point of time the timestamp is taken in relation to + the frame. Logical and operation between the + <structfield>flags</structfield> field and + <constant>V4L2_BUF_FLAG_TSTAMP_SRC_MASK</constant> produces the + value of the timestamp source.</entry> + </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_EOF</constant></entry> + <entry>0x00000000</entry> + <entry>"End of frame." The buffer timestamp has been taken when + the last pixel of the frame has been received.</entry> + </row> + <row> + <entry><constant>V4L2_BUF_FLAG_TSTAMP_SRC_SOE</constant></entry> + <entry>0x00010000</entry> + <entry>"Start of exposure." The buffer timestamp has been taken + when the exposure of the frame has begun.</entry> + </row> </tbody> </tgroup> </table> diff --git a/drivers/media/usb/uvc/uvc_queue.c b/drivers/media/usb/uvc/uvc_queue.c index cd962be..a9292d2 100644 --- a/drivers/media/usb/uvc/uvc_queue.c +++ b/drivers/media/usb/uvc/uvc_queue.c @@ -149,7 +149,8 @@ int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, queue->queue.buf_struct_size = sizeof(struct uvc_buffer); queue->queue.ops = &uvc_queue_qops; queue->queue.mem_ops = &vb2_vmalloc_memops; - queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC; + queue->queue.timestamp_type = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC + | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; ret = vb2_queue_init(&queue->queue); if (ret) return ret; diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index bef53ce..b6b992d 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -312,6 +312,8 @@ struct v4l2_fh; * @buf_struct_size: size of the driver-specific buffer structure; * "0" indicates the driver doesn't want to use a custom buffer * structure type, so sizeof(struct vb2_buffer) will is used + * @timestamp_type: Timestamp flags; V4L2_BUF_FLAGS_TIMESTAMP_* and + * V4L2_BUF_FLAGS_TSTAMP_SRC_* * @gfp_flags: additional gfp flags used when allocating the buffers. * Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32 * to force the buffer allocation to a specific memory zone. diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index e9ee444..82e8661 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -695,6 +695,10 @@ struct v4l2_buffer { #define V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN 0x00000000 #define V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 0x00002000 #define V4L2_BUF_FLAG_TIMESTAMP_COPY 0x00004000 +/* Timestamp sources. */ +#define V4L2_BUF_FLAG_TSTAMP_SRC_MASK 0x00070000 +#define V4L2_BUF_FLAG_TSTAMP_SRC_EOF 0x00000000 +#define V4L2_BUF_FLAG_TSTAMP_SRC_SOE 0x00010000 /** * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor
Some devices do not produce timestamps that correspond to the end of the frame. The user space should be informed on the matter. This patch achieves that by adding buffer flags (and a mask) for timestamp sources since more possible timestamping points are expected than just two. A three-bit mask is defined (V4L2_BUF_FLAG_TSTAMP_SRC_MASK) and two of the eight possible values is are defined V4L2_BUF_FLAG_TSTAMP_SRC_EOF for end of frame (value zero) V4L2_BUF_FLAG_TSTAMP_SRC_SOE for start of exposure (next value). Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi> --- since v4.1: - Replace SOF flag by SOE flag - Add mask for timestamp sources Documentation/DocBook/media/v4l/io.xml | 28 ++++++++++++++++++++++------ drivers/media/usb/uvc/uvc_queue.c | 3 ++- include/media/videobuf2-core.h | 2 ++ include/uapi/linux/videodev2.h | 4 ++++ 4 files changed, 30 insertions(+), 7 deletions(-)