Hi Sakari, > From: Sakari Ailus [mailto:sakari.ailus@xxxxxx] > Sent: Saturday, February 15, 2014 9:53 PM > > 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). > Changes in videobuf2-core.c look good. > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx> Acked-by: Kamil Debski <k.debski@xxxxxxxxxxx> > --- > Documentation/DocBook/media/v4l/io.xml | 31 > ++++++++++++++++++++++++------ > drivers/media/v4l2-core/videobuf2-core.c | 4 +++- > include/media/videobuf2-core.h | 2 ++ > include/uapi/linux/videodev2.h | 4 ++++ > 4 files changed, 34 insertions(+), 7 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/io.xml > b/Documentation/DocBook/media/v4l/io.xml > index 46d24b3..fbd0c6e 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -653,12 +653,6 @@ 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"> > @@ -1119,6 +1113,31 @@ 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 or the > + last pixel of the frame has been transmitted.</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. This is only > + valid for buffer type > + <constant>V4L2_BUF_TYPE_VIDEO_CAPTURE</constant>.</entry> > + </row> > </tbody> > </tgroup> > </table> > diff --git a/drivers/media/v4l2-core/videobuf2-core.c > b/drivers/media/v4l2-core/videobuf2-core.c > index 5a5fb7f..6e314b0 100644 > --- a/drivers/media/v4l2-core/videobuf2-core.c > +++ b/drivers/media/v4l2-core/videobuf2-core.c > @@ -2195,7 +2195,9 @@ int vb2_queue_init(struct vb2_queue *q) > WARN_ON(!q->io_modes) || > WARN_ON(!q->ops->queue_setup) || > WARN_ON(!q->ops->buf_queue) || > - WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK)) > + WARN_ON(q->timestamp_type & > + ~(V4L2_BUF_FLAG_TIMESTAMP_MASK | > + V4L2_BUF_FLAG_TSTAMP_SRC_MASK))) > return -EINVAL; Looks good. > > /* Warn that the driver should choose an appropriate timestamp > type */ 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 > -- > 1.7.10.4 Best wishes, -- Kamil Debski Samsung R&D Institute Poland -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
