Hi Arun,
On 14/05/14 08:59, Arun Kumar K wrote:
> This event indicates that the video device has encountered
> a source parameter change during runtime. This can typically be a
> resolution change detected by a video decoder OR a format change
> detected by an input connector.
>
> This needs to be nofified to the userspace and the application may
> be expected to reallocate buffers before proceeding. The application
> can subscribe to events on a specific pad or input port which
> it is interested in.
>
> Signed-off-by: Arun Kumar K <arun...@samsung.com>
This looks like a nice API enhancement.
Acked-by: Sylwester Nawrocki <s.nawro...@samsung.com>
> ---
> Documentation/DocBook/media/v4l/vidioc-dqevent.xml | 33 ++++++++++++++++++
> .../DocBook/media/v4l/vidioc-subscribe-event.xml | 20 +++++++++++
> drivers/media/v4l2-core/v4l2-event.c | 36
> ++++++++++++++++++++
> include/media/v4l2-event.h | 4 +++
> include/uapi/linux/videodev2.h | 8 +++++
> 5 files changed, 101 insertions(+)
>
> diff --git a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
> b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
> index 89891ad..820f86e 100644
> --- a/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
> +++ b/Documentation/DocBook/media/v4l/vidioc-dqevent.xml
> @@ -242,6 +242,22 @@
> </tgroup>
> </table>
>
> + <table frame="none" pgwide="1" id="v4l2-event-src-change">
> + <title>struct <structname>v4l2_event_src_change</structname></title>
> + <tgroup cols="3">
> + &cs-str;
> + <tbody valign="top">
> + <row>
> + <entry>__u32</entry>
> + <entry><structfield>changes</structfield></entry>
> + <entry>
> + A bitmask that tells what has changed. See <xref
> linkend="src-changes-flags" />.
> + </entry>
> + </row>
> + </tbody>
> + </tgroup>
> + </table>
> +
> <table pgwide="1" frame="none" id="changes-flags">
> <title>Changes</title>
> <tgroup cols="3">
> @@ -270,6 +286,23 @@
> </tbody>
> </tgroup>
> </table>
> +
> + <table pgwide="1" frame="none" id="src-changes-flags">
> + <title>Source Changes</title>
> + <tgroup cols="3">
> + &cs-def;
> + <tbody valign="top">
> + <row>
> + <entry><constant>V4L2_EVENT_SRC_CH_RESOLUTION</constant></entry>
> + <entry>0x0001</entry>
> + <entry>This event gets triggered when a resolution change is
> + detected at an input. This can come from an input connector or
> + from a video decoder.
> + </entry>
> + </row>
> + </tbody>
> + </tgroup>
> + </table>
> </refsect1>
> <refsect1>
> &return-value;
> diff --git a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
> b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
> index 5c70b61..f016254 100644
> --- a/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
> +++ b/Documentation/DocBook/media/v4l/vidioc-subscribe-event.xml
> @@ -155,6 +155,26 @@
> </entry>
> </row>
> <row>
> + <entry><constant>V4L2_EVENT_SOURCE_CHANGE</constant></entry>
> + <entry>5</entry>
> + <entry>
> + <para>This event is triggered when a source parameter change is
> + detected during runtime by the video device. It can be a
> + runtime resolution change triggered by a video decoder or the
> + format change happening on an input connector.
> + This event requires that the <structfield>id</structfield>
> + matches the input index (when used with a video device node)
> + or the pad index (when used with a subdevice node) from which
> + you want to receive events.</para>
> +
> + <para>This event has a &v4l2-event-source-change; associated
> + with it. The <structfield>changes</structfield> bitfield denotes
> + what has changed for the subscribed pad. If multiple events
> + occurred before application could dequeue them, then the changes
> + will have the ORed value of all the events generated.</para>
> + </entry>
> + </row>
> + <row>
> <entry><constant>V4L2_EVENT_PRIVATE_START</constant></entry>
> <entry>0x08000000</entry>
> <entry>Base event number for driver-private events.</entry>
> diff --git a/drivers/media/v4l2-core/v4l2-event.c
> b/drivers/media/v4l2-core/v4l2-event.c
> index 86dcb54..8761aab 100644
> --- a/drivers/media/v4l2-core/v4l2-event.c
> +++ b/drivers/media/v4l2-core/v4l2-event.c
> @@ -318,3 +318,39 @@ int v4l2_event_subdev_unsubscribe(struct v4l2_subdev
> *sd, struct v4l2_fh *fh,
> return v4l2_event_unsubscribe(fh, sub);
> }
> EXPORT_SYMBOL_GPL(v4l2_event_subdev_unsubscribe);
> +
> +static void v4l2_event_src_replace(struct v4l2_event *old,
> + const struct v4l2_event *new)
> +{
> + u32 old_changes = old->u.src_change.changes;
> +
> + old->u.src_change = new->u.src_change;
> + old->u.src_change.changes |= old_changes;
> +}
> +
> +static void v4l2_event_src_merge(const struct v4l2_event *old,
> + struct v4l2_event *new)
> +{
> + new->u.src_change.changes |= old->u.src_change.changes;
> +}
> +
> +static const struct v4l2_subscribed_event_ops v4l2_event_src_ch_ops = {
> + .replace = v4l2_event_src_replace,
> + .merge = v4l2_event_src_merge,
> +};
> +
> +int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
> + const struct v4l2_event_subscription *sub)
> +{
> + if (sub->type == V4L2_EVENT_SOURCE_CHANGE)
> + return v4l2_event_subscribe(fh, sub, 0, &v4l2_event_src_ch_ops);
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_src_change_event_subscribe);
> +
> +int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
> + struct v4l2_fh *fh, struct v4l2_event_subscription *sub)
> +{
> + return v4l2_src_change_event_subscribe(fh, sub);
> +}
> +EXPORT_SYMBOL_GPL(v4l2_src_change_event_subdev_subscribe);
> diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
> index be05d01..1ab9045 100644
> --- a/include/media/v4l2-event.h
> +++ b/include/media/v4l2-event.h
> @@ -132,4 +132,8 @@ int v4l2_event_unsubscribe(struct v4l2_fh *fh,
> void v4l2_event_unsubscribe_all(struct v4l2_fh *fh);
> int v4l2_event_subdev_unsubscribe(struct v4l2_subdev *sd, struct v4l2_fh *fh,
> struct v4l2_event_subscription *sub);
> +int v4l2_src_change_event_subscribe(struct v4l2_fh *fh,
> + const struct v4l2_event_subscription *sub);
> +int v4l2_src_change_event_subdev_subscribe(struct v4l2_subdev *sd,
> + struct v4l2_fh *fh, struct v4l2_event_subscription *sub);
> #endif /* V4L2_EVENT_H */
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index ea468ee..b923d91 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1765,6 +1765,7 @@ struct v4l2_streamparm {
> #define V4L2_EVENT_EOS 2
> #define V4L2_EVENT_CTRL 3
> #define V4L2_EVENT_FRAME_SYNC 4
> +#define V4L2_EVENT_SOURCE_CHANGE 5
> #define V4L2_EVENT_PRIVATE_START 0x08000000
>
> /* Payload for V4L2_EVENT_VSYNC */
> @@ -1796,12 +1797,19 @@ struct v4l2_event_frame_sync {
> __u32 frame_sequence;
> };
>
> +#define V4L2_EVENT_SRC_CH_RESOLUTION (1 << 0)
> +
> +struct v4l2_event_src_change {
> + __u32 changes;
> +};
> +
> struct v4l2_event {
> __u32 type;
> union {
> struct v4l2_event_vsync vsync;
> struct v4l2_event_ctrl ctrl;
> struct v4l2_event_frame_sync frame_sync;
> + struct v4l2_event_src_change src_change;
> __u8 data[64];
> } u;
> __u32 pending;
>
--
Sylwester Nawrocki
Samsung R&D Institute Poland
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