On Sat, 2010-02-27 at 10:35 +0100, Martin Dauskardt wrote: > The ivtv README.vbi says: > > --------------------------------------------------------------------------------------- > #define VBI_TYPE_TELETEXT 0x1 // Teletext (uses lines 6-22 for > PAL, > 10-21 for NTSC) > #define VBI_TYPE_CC 0x4 // Closed Captions (line 21 NTSC, > line > 22 PAL) > #define VBI_TYPE_WSS 0x5 // Wide Screen Signal (line 20 NTSC, > line 23 PAL) > #define VBI_TYPE_VPS 0x7 // Video Programming System (PAL) > (line 16) > > Note that currently only Program Streams are supported! > > ...
Note that I have moved the documentation contained in linux/Documentation/video4linux/cx2341x/README.vbi to the V4L2 API specification document. I added some comments to note where things are stored little endian in the MPEG stream. Please refer to that official API documentation. > TODO > ==== > ... > > 5) Support the VBI data insertion for more stream types than just Program > Stream. > ---------------------------------------------------------------------------------------- I'm not sure where this TODO list is. > Is this still up-to-date? No VBI Teletext for V4L2_MPEG_STREAM_TYPE_MPEG2_TS? > > Does it also apply to the cx18 driver? Here is the state of things as I know it: 1. Very old CX23415/6 firmware supported producing a TS, but that feature was removed. I have unverified information that the latest CX23415/6 firmwares may support a TS again. I have not verified this, nor is the ivtv driver set to allow it. CX2341X_CAP_HAS_TS is not set for ivtv. 2. CX23418 firmware can produce a TS and CX2341X_CAP_HAS_TS is set for cx18. 3. If requested, the ivtv driver will attempt to splice in ivtv VBI Private Packets into the stream, no matter what the stream type. This is probably wrong for the MPEG 1 stream types. 4. If reuqested, the cx18 driver will attempt to splice in ivtv style VBI private packets into the stream, only for *non-TS* MPEG-2 stream types. This means the MPEG 1 stream types and MPEG 2 TS stream types are left alone, as the algorithm in the driver doesn't know how to stuff extra data into these stream types (Patches are welcome of course). The packet insertion algorithm may be wrong for the MPEG-2 DVD stream type, but I haven't checked crefully, so the driver does it anyway. 5. The ivtv driver can properly correct MPEG 2 PS index records when performing ivtv VBI packet insertion. 6. The cx18 driver cannot properly correct MPEG 2 index records when performing ivtv-style VBI packet insertion, and will inhibit generating MPEG index entries when ivtv-style VBI packet insertion is turned on. (Only one test application uses the VIDIOC_G_ENC_INDEX call AFAIK, so this is likely no big impact.) > In the v4l2 specifications I can only find V4L2_SLICED_TELETEXT_B (Teletext > System B) which is described as beeing for PAL/SECAM. > Is there also a way to slice vbi teletext data for NTSC? Even though the 525 line, 60 Hz Teletext standard exists, it is never used for NTSC. Do you know of a PAL-M system (or something else) in use in the world that needs it? Regards, Andy > Greets, > Martin _______________________________________________ ivtv-devel mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-devel
