v4l: added V4L2_BUF_FLAG_EOS flag indicating the last frame in the stream
Some devices requires indicator if the buffer is the last one in the stream.
Applications and drivers can use this flag in such case.
Signed-off-by: Andrzej Hajda <a.hajda@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Hello,
This patch adds new v4l2_buffer flag V4L2_BUF_FLAG_EOS. This flag is set
by applications on the output buffer to indicate the last buffer of the stream.
Some devices (eg. s5p_mfc) requires presence of the end-of-stream indicator
together with the last buffer.
Common practice of sending empty buffer to indicate end-of-strem do not work in
such case.
I would like to ask for review and comments.
Apologies for duplicated e-mails - sendmail problems.
Regards
Andrzej Hajda
---
Documentation/DocBook/media/v4l/io.xml | 7 +++++++
Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 2 ++
include/linux/videodev2.h | 1 +
3 files changed, 10 insertions(+), 0 deletions(-)
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml
index b815929..7985ca9 100644
--- a/Documentation/DocBook/media/v4l/io.xml
+++ b/Documentation/DocBook/media/v4l/io.xml
@@ -954,6 +954,13 @@ Typically applications shall use this flag for output buffers if the data
in this buffer has not been created by the CPU but by some DMA-capable unit,
in which case caches have not been used.</entry>
</row>
+ <row>
+ <entry><constant>V4L2_BUF_FLAG_EOS</constant></entry>
+ <entry>0x2000</entry>
+ <entry>Application should set this flag in the output buffer
+in order to inform the driver about the last frame of the stream. Some
+drivers may require it to properly finish processing the stream.</entry>
+ </row>
</tbody>
</tgroup>
</table>
diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
index 9caa49a..ad49f7d 100644
--- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml
@@ -76,6 +76,8 @@ supports capturing from specific video inputs and you want to specify a video
input, then <structfield>flags</structfield> should be set to
<constant>V4L2_BUF_FLAG_INPUT</constant> and the field
<structfield>input</structfield> must be initialized to the desired input.
+Some drivers expects applications set <constant>V4L2_BUF_FLAG_EOS</constant>
+flag on the last buffer of the stream.
The <structfield>reserved</structfield> field must be set to 0. When using
the <link linkend="planar-apis">multi-planar API</link>, the
<structfield>m.planes</structfield> field must contain a userspace pointer
diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index c9c9a46..d1d3406 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -671,6 +671,7 @@ struct v4l2_buffer {
/* Cache handling flags */
#define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0800
#define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x1000
+#define V4L2_BUF_FLAG_EOS 0x2000 /* The last buffer in the stream */
/*
* O V E R L A Y P R E V I E W
--
1.7.0.4
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