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author | Hans Verkuil <hans.verkuil@cisco.com> | 2012-05-15 08:04:28 -0300 |
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committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2012-05-20 08:18:03 -0300 |
commit | 7dcc606b2a980222d9816d092a5c20b7c98cbd1a (patch) | |
tree | cf1ca07dbab8a0fb9a6e73963367310039e5c3a0 /Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml | |
parent | 06bba75d2a3e0bf558421b7548a6248ed5c7bfec (diff) | |
download | op-kernel-dev-7dcc606b2a980222d9816d092a5c20b7c98cbd1a.zip op-kernel-dev-7dcc606b2a980222d9816d092a5c20b7c98cbd1a.tar.gz |
[media] V4L2 spec: document the new V4L2 DV timings ioctls
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml')
-rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml | 130 |
1 files changed, 119 insertions, 11 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml b/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml index 4a8648a..eda1a29 100644 --- a/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml +++ b/Documentation/DocBook/media/v4l/vidioc-g-dv-timings.xml @@ -7,7 +7,7 @@ <refnamediv> <refname>VIDIOC_G_DV_TIMINGS</refname> <refname>VIDIOC_S_DV_TIMINGS</refname> - <refpurpose>Get or set custom DV timings for input or output</refpurpose> + <refpurpose>Get or set DV timings for input or output</refpurpose> </refnamediv> <refsynopsisdiv> @@ -48,12 +48,15 @@ <refsect1> <title>Description</title> - <para>To set custom DV timings for the input or output, applications use the -<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current custom timings, + <para>To set DV timings for the input or output, applications use the +<constant>VIDIOC_S_DV_TIMINGS</constant> ioctl and to get the current timings, applications use the <constant>VIDIOC_G_DV_TIMINGS</constant> ioctl. The detailed timing information is filled in using the structure &v4l2-dv-timings;. These ioctls take a pointer to the &v4l2-dv-timings; structure as argument. If the ioctl is not supported or the timing values are not correct, the driver returns &EINVAL;.</para> +<para>The <filename>linux/v4l2-dv-timings.h</filename> header can be used to get the +timings of the formats in the <xref linkend="cea861" /> and <xref linkend="vesadmt" /> +standards.</para> </refsect1> <refsect1> @@ -83,12 +86,13 @@ or the timing values are not correct, the driver returns &EINVAL;.</para> <row> <entry>__u32</entry> <entry><structfield>width</structfield></entry> - <entry>Width of the active video in pixels</entry> + <entry>Width of the active video in pixels.</entry> </row> <row> <entry>__u32</entry> <entry><structfield>height</structfield></entry> - <entry>Height of the active video in lines</entry> + <entry>Height of the active video frame in lines. So for interlaced formats the + height of the active video in each field is <structfield>height</structfield>/2.</entry> </row> <row> <entry>__u32</entry> @@ -125,32 +129,52 @@ bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_H <row> <entry>__u32</entry> <entry><structfield>vfrontporch</structfield></entry> - <entry>Vertical front porch in lines</entry> + <entry>Vertical front porch in lines. For interlaced formats this refers to the + odd field (aka field 1).</entry> </row> <row> <entry>__u32</entry> <entry><structfield>vsync</structfield></entry> - <entry>Vertical sync length in lines</entry> + <entry>Vertical sync length in lines. For interlaced formats this refers to the + odd field (aka field 1).</entry> </row> <row> <entry>__u32</entry> <entry><structfield>vbackporch</structfield></entry> - <entry>Vertical back porch in lines</entry> + <entry>Vertical back porch in lines. For interlaced formats this refers to the + odd field (aka field 1).</entry> </row> <row> <entry>__u32</entry> <entry><structfield>il_vfrontporch</structfield></entry> - <entry>Vertical front porch in lines for bottom field of interlaced field formats</entry> + <entry>Vertical front porch in lines for the even field (aka field 2) of + interlaced field formats.</entry> </row> <row> <entry>__u32</entry> <entry><structfield>il_vsync</structfield></entry> - <entry>Vertical sync length in lines for bottom field of interlaced field formats</entry> + <entry>Vertical sync length in lines for the even field (aka field 2) of + interlaced field formats.</entry> </row> <row> <entry>__u32</entry> <entry><structfield>il_vbackporch</structfield></entry> - <entry>Vertical back porch in lines for bottom field of interlaced field formats</entry> + <entry>Vertical back porch in lines for the even field (aka field 2) of + interlaced field formats.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>standards</structfield></entry> + <entry>The video standard(s) this format belongs to. This will be filled in by + the driver. Applications must set this to 0. See <xref linkend="dv-bt-standards"/> + for a list of standards.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry>Several flags giving more information about the format. + See <xref linkend="dv-bt-flags"/> for a description of the flags. + </entry> </row> </tbody> </tgroup> @@ -211,6 +235,90 @@ bit 0 (V4L2_DV_VSYNC_POS_POL) is for vertical sync polarity and bit 1 (V4L2_DV_H </tbody> </tgroup> </table> + <table pgwide="1" frame="none" id="dv-bt-standards"> + <title>DV BT Timing standards</title> + <tgroup cols="2"> + &cs-str; + <tbody valign="top"> + <row> + <entry>Timing standard</entry> + <entry>Description</entry> + </row> + <row> + <entry></entry> + <entry></entry> + </row> + <row> + <entry>V4L2_DV_BT_STD_CEA861</entry> + <entry>The timings follow the CEA-861 Digital TV Profile standard</entry> + </row> + <row> + <entry>V4L2_DV_BT_STD_DMT</entry> + <entry>The timings follow the VESA Discrete Monitor Timings standard</entry> + </row> + <row> + <entry>V4L2_DV_BT_STD_CVT</entry> + <entry>The timings follow the VESA Coordinated Video Timings standard</entry> + </row> + <row> + <entry>V4L2_DV_BT_STD_GTF</entry> + <entry>The timings follow the VESA Generalized Timings Formula standard</entry> + </row> + </tbody> + </tgroup> + </table> + <table pgwide="1" frame="none" id="dv-bt-flags"> + <title>DV BT Timing flags</title> + <tgroup cols="2"> + &cs-str; + <tbody valign="top"> + <row> + <entry>Flag</entry> + <entry>Description</entry> + </row> + <row> + <entry></entry> + <entry></entry> + </row> + <row> + <entry>V4L2_DV_FL_REDUCED_BLANKING</entry> + <entry>CVT/GTF specific: the timings use reduced blanking (CVT) or the 'Secondary +GTF' curve (GTF). In both cases the horizontal and/or vertical blanking +intervals are reduced, allowing a higher resolution over the same +bandwidth. This is a read-only flag, applications must not set this. + </entry> + </row> + <row> + <entry>V4L2_DV_FL_CAN_REDUCE_FPS</entry> + <entry>CEA-861 specific: set for CEA-861 formats with a framerate that is a multiple +of six. These formats can be optionally played at 1 / 1.001 speed to +be compatible with 60 Hz based standards such as NTSC and PAL-M that use a framerate of +29.97 frames per second. If the transmitter can't generate such frequencies, then the +flag will also be cleared. This is a read-only flag, applications must not set this. + </entry> + </row> + <row> + <entry>V4L2_DV_FL_REDUCED_FPS</entry> + <entry>CEA-861 specific: only valid for video transmitters, the flag is cleared +by receivers. It is also only valid for formats with the V4L2_DV_FL_CAN_REDUCE_FPS flag +set, for other formats the flag will be cleared by the driver. + +If the application sets this flag, then the pixelclock used to set up the transmitter is +divided by 1.001 to make it compatible with NTSC framerates. If the transmitter +can't generate such frequencies, then the flag will also be cleared. + </entry> + </row> + <row> + <entry>V4L2_DV_FL_HALF_LINE</entry> + <entry>Specific to interlaced formats: if set, then field 1 (aka the odd field) +is really one half-line longer and field 2 (aka the even field) is really one half-line +shorter, so each field has exactly the same number of half-lines. Whether half-lines can be +detected or used depends on the hardware. + </entry> + </row> + </tbody> + </tgroup> + </table> </refsect1> <refsect1> &return-value; |