X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=Documentation%2FDocBook%2Fv4l%2Fdev-teletext.xml;h=414b1cfff9f48f50d27cd2784eb433c8fa4ef400;hb=2301b65b86df8b80e6779ce9885ad62a5c4adc38;hp=76184e8ed618aed65b4b06206490f759e507ac32;hpb=a80a66caf8110fc33af8013353fe0da0ae553a13;p=pandora-kernel.git diff --git a/Documentation/DocBook/v4l/dev-teletext.xml b/Documentation/DocBook/v4l/dev-teletext.xml index 76184e8ed618..414b1cfff9f4 100644 --- a/Documentation/DocBook/v4l/dev-teletext.xml +++ b/Documentation/DocBook/v4l/dev-teletext.xml @@ -1,35 +1,32 @@ Teletext Interface - This interface aims at devices receiving and demodulating + This interface was aimed at devices receiving and demodulating Teletext data [, ], evaluating the Teletext packages and storing formatted pages in cache memory. Such devices are usually implemented as microcontrollers with serial -interface (I2C) and can be found on older +interface (I2C) and could be found on old TV cards, dedicated Teletext decoding cards and home-brew devices connected to the PC parallel port. - The Teletext API was designed by Martin Buck. It is defined in + The Teletext API was designed by Martin Buck. It was defined in the kernel header file linux/videotext.h, the specification is available from ftp://ftp.gwdg.de/pub/linux/misc/videotext/. (Videotext is the name of -the German public television Teletext service.) Conventional character -device file names are /dev/vtx and -/dev/vttuner, with device number 83, 0 and 83, 16 -respectively. A similar interface exists for the Philips SAA5249 -Teletext decoder [specification?] with character device file names -/dev/tlkN, device number 102, N. +the German public television Teletext service.) Eventually the Teletext API was integrated into the V4L API with character device file names /dev/vtx0 to /dev/vtx31, device major number 81, minor numbers -192 to 223. For reference the V4L Teletext API specification is -reproduced here in full: "Teletext interfaces talk the existing VTX -API." Teletext devices with major number 83 and 102 will be removed in -Linux 2.6. +192 to 223. - There are no plans to replace the Teletext API or to integrate -it into V4L2. Please write to the linux-media mailing list: &v4l-ml; -when the need arises. + 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. + + Modern devices all use the raw or +sliced VBI API.