diff options
Diffstat (limited to 'Documentation/DocBook/v4l/compat.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/compat.xml | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/Documentation/DocBook/v4l/compat.xml b/Documentation/DocBook/v4l/compat.xml index b42b935913c..c9ce61d981f 100644 --- a/Documentation/DocBook/v4l/compat.xml +++ b/Documentation/DocBook/v4l/compat.xml @@ -21,11 +21,15 @@ API.</para> <title>Opening and Closing Devices</title> <para>For compatibility reasons the character device file names -recommended for V4L2 video capture, overlay, radio, teletext and raw +recommended for V4L2 video capture, overlay, radio and raw vbi capture devices did not change from those used by V4L. They are listed in <xref linkend="devices" /> and below in <xref linkend="v4l-dev" />.</para> + <para>The teletext devices (minor range 192-223) have been removed in +V4L2 and no longer exist. There is no hardware available anymore for handling +pure teletext. Instead raw or sliced VBI is used.</para> + <para>The V4L <filename>videodev</filename> module automatically assigns minor numbers to drivers in load order, depending on the registered device type. We recommend that V4L2 drivers by default @@ -66,13 +70,6 @@ not compatible with V4L or V4L2.</para> </footnote>, <entry>64-127</entry> </row> <row> - <entry>Teletext decoder</entry> - <entry><para><filename>/dev/vtx</filename>, -<filename>/dev/vtx0</filename> to -<filename>/dev/vtx31</filename></para></entry> - <entry>192-223</entry> - </row> - <row> <entry>Raw VBI capture</entry> <entry><para><filename>/dev/vbi</filename>, <filename>/dev/vbi0</filename> to @@ -1091,8 +1088,9 @@ signed 64-bit integer. Output devices should not send a buffer out until the time in the timestamp field has arrived. I would like to follow SGI's lead, and adopt a multimedia timestamping system like their UST (Unadjusted System Time). See -http://reality.sgi.com/cpirazzi_engr/lg/time/intro.html. [This link is -no longer valid.] UST uses timestamps that are 64-bit signed integers +http://web.archive.org/web/*/http://reality.sgi.com +/cpirazzi_engr/lg/time/intro.html. +UST uses timestamps that are 64-bit signed integers (not struct timeval's) and given in nanosecond units. The UST clock starts at zero when the system is booted and runs continuously and uniformly. It takes a little over 292 years for UST to overflow. There @@ -2344,6 +2342,17 @@ more information.</para> </listitem> </orderedlist> </section> + <section> + <title>V4L2 in Linux 2.6.37</title> + <orderedlist> + <listitem> + <para>Remove the vtx (videotext/teletext) API. This API was no longer +used and no hardware exists to verify the API. Nor were any userspace applications found +that used it. It was originally scheduled for removal in 2.6.35. + </para> + </listitem> + </orderedlist> + </section> <section id="other"> <title>Relation of V4L2 to other Linux multimedia APIs</title> |