diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
---|---|---|
committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/DocBook/media/v4l/dev-teletext.xml | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/DocBook/media/v4l/dev-teletext.xml')
-rw-r--r-- | kernel/Documentation/DocBook/media/v4l/dev-teletext.xml | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/kernel/Documentation/DocBook/media/v4l/dev-teletext.xml b/kernel/Documentation/DocBook/media/v4l/dev-teletext.xml new file mode 100644 index 000000000..bd21c64d7 --- /dev/null +++ b/kernel/Documentation/DocBook/media/v4l/dev-teletext.xml @@ -0,0 +1,29 @@ + <title>Teletext Interface</title> + + <para>This interface was aimed at devices receiving and demodulating +Teletext data [<xref linkend="ets300706" />, <xref linkend="itu653" />], evaluating the +Teletext packages and storing formatted pages in cache memory. Such +devices are usually implemented as microcontrollers with serial +interface (I<superscript>2</superscript>C) and could be found on old +TV cards, dedicated Teletext decoding cards and home-brew devices +connected to the PC parallel port.</para> + + <para>The Teletext API was designed by Martin Buck. It was defined in +the kernel header file <filename>linux/videotext.h</filename>, the +specification is available from <ulink url="ftp://ftp.gwdg.de/pub/linux/misc/videotext/"> +ftp://ftp.gwdg.de/pub/linux/misc/videotext/</ulink>. (Videotext is the name of +the German public television Teletext service.)</para> + + <para>Eventually the Teletext API was integrated into the V4L API +with character device file names <filename>/dev/vtx0</filename> to +<filename>/dev/vtx31</filename>, device major number 81, minor numbers +192 to 223.</para> + + <para>However, teletext decoders were quickly replaced by more +generic VBI demodulators and those dedicated teletext decoders no longer exist. +For many years the vtx devices were still around, even though nobody used +them. So the decision was made to finally remove support for the Teletext API in +kernel 2.6.37.</para> + + <para>Modern devices all use the <link linkend="raw-vbi">raw</link> or +<link linkend="sliced">sliced</link> VBI API.</para> |