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| author | Philipp Zabel <p.zabel@pengutronix.de> | 2015-05-04 12:51:04 +0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2015-05-12 08:50:53 +0200 |
| commit | 8cee396bfa77ce3a2e5fe48f597206c1cd547f9c (patch) | |
| tree | 04676c7cb74ea8d58b4c4f1d43af192a166080dc /Documentation/DocBook/media/v4l/vidioc-qbuf.xml | |
| parent | [media] media: platform: s5p: Constify platform_device_id (diff) | |
| download | linux-8cee396bfa77ce3a2e5fe48f597206c1cd547f9c.tar.xz linux-8cee396bfa77ce3a2e5fe48f597206c1cd547f9c.zip | |
[media] DocBook media: document codec draining flow
Document the interaction between VIDIOC_DECODER_CMD V4L2_DEC_CMD_STOP and
VIDIOC_ENCODER_CMD V4L2_ENC_CMD_STOP to start the draining, the V4L2_EVENT_EOS
event signalling all capture buffers are finished and ready to be dequeud,
the new V4L2_BUF_FLAG_LAST buffer flag indicating the last buffer being dequeued
from the capture queue, and the poll and VIDIOC_DQBUF ioctl return values once
the queue is drained.
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-qbuf.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml index 3504a7f2f382..6cfc53b83a20 100644 --- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml @@ -186,6 +186,14 @@ In that case the application should be able to safely reuse the buffer and continue streaming. </para> </listitem> + <term><errorcode>EPIPE</errorcode></term> + <listitem> + <para><constant>VIDIOC_DQBUF</constant> returns this on an empty +capture queue for mem2mem codecs if a buffer with the +<constant>V4L2_BUF_FLAG_LAST</constant> was already dequeued and no new buffers +are expected to become available. + </para> + </listitem> </varlistentry> </variablelist> </refsect1> |