diff options
Diffstat (limited to 'Documentation/DocBook/media/v4l/dev-raw-vbi.xml')
| -rw-r--r-- | Documentation/DocBook/media/v4l/dev-raw-vbi.xml | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/Documentation/DocBook/media/v4l/dev-raw-vbi.xml b/Documentation/DocBook/media/v4l/dev-raw-vbi.xml index b788c72c885e..f4b61b6ce3c2 100644 --- a/Documentation/DocBook/media/v4l/dev-raw-vbi.xml +++ b/Documentation/DocBook/media/v4l/dev-raw-vbi.xml @@ -150,9 +150,15 @@ signal. Drivers shall not convert the sample format by software.</para></entry> <entry>This is the scanning system line number associated with the first line of the VBI image, of the first and the second field respectively. See <xref linkend="vbi-525" /> and -<xref linkend="vbi-625" /> for valid values. VBI input drivers can -return start values 0 if the hardware cannot reliable identify -scanning lines, VBI acquisition may not require this +<xref linkend="vbi-625" /> for valid values. +The <constant>V4L2_VBI_ITU_525_F1_START</constant>, +<constant>V4L2_VBI_ITU_525_F2_START</constant>, +<constant>V4L2_VBI_ITU_625_F1_START</constant> and +<constant>V4L2_VBI_ITU_625_F2_START</constant> defines give the start line +numbers for each field for each 525 or 625 line format as a convenience. +Don't forget that ITU line numbering starts at 1, not 0. +VBI input drivers can return start values 0 if the hardware cannot +reliable identify scanning lines, VBI acquisition may not require this information.</entry> </row> <row> |