V4L/DVB: V4L2 Spec: Improve the VIDIOC_QUERY_DV_PRESET description

Make explicit what should happen when the input signal is missing,
unreliable or does not map to a supported preset.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Hans Verkuil 2010-05-09 06:54:46 -03:00 committed by Mauro Carvalho Chehab
parent 51ff9ef133
commit f1158af2b2

View file

@ -53,8 +53,10 @@ input</refpurpose>
automatically, similar to sensing the video standard. To do so, applications
call <constant> VIDIOC_QUERY_DV_PRESET</constant> with a pointer to a
&v4l2-dv-preset; type. Once the hardware detects a preset, that preset is
returned in the preset field of &v4l2-dv-preset;. When detection is not
possible or fails, the value V4L2_DV_INVALID is returned.</para>
returned in the preset field of &v4l2-dv-preset;. If the preset could not be
detected because there was no signal, or the signal was unreliable, or the
signal did not map to a supported preset, then the value V4L2_DV_INVALID is
returned.</para>
</refsect1>
<refsect1>