[ivtv-devel] VBI errors on NTSC Cable channels 56 and 57 - ivtv problem?

Rich Kadel Fri, 14 Jul 2006 20:16:21 -0700

OK. I verified that the PVR-500 does NOT have this problem in Windows Media Center.

When I use zvbi to extract VBI closed caption and XDS information, I get constant parity errors on channel 56 (NTSC broadcast), making the CC data unusable. (I’m not sure a single character is right). On channel 57, I get frequent Parity errors (about every 10 Line-21’s or so). Channels 54, 55, 58, and 59 are very clean.

When I look at the video on channel 56, it appears OK.

I am using ivtv 0.4.6.

Is this an IVTV problem? Is it a known problem?

It does not appear to be a problem with the card, since the card works in Windows.

As mentioned in the thread below, this occurs on multiple Linux machines, in different locations (miles apart) but with the same cable provider.

Thanks,

Rich

Rich Kadel

Know'bout, Inc.

(858) 433-1747

www.knowbout.com

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From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rich Kadel
Sent: Friday, July 07, 2006 6:19 PM
To: 'User discussion about IVTV'; [email protected]
Subject: [ivtv-devel] Problems with PVR-x/IVTV and VBI data on certainchannels

Does anyone know why I get parity errors when trying to extract VBI data (e.g., closed captioning) on certain channels?

For comparison, on a Windows PC, using a Conexant Falcon-II based card that appears to come from ASUSTEK (it was bundled in the Windows Media Center HP Pavilliion I got), the closed caption comes through Media Center “loud and clear”.

However, on Linux (Centos 4.3), using IVTV and the ZVBI library, I have not been able to read VBI on Channels 56 and 57. 55 works fine, as do many other channels. I have not tested exhaustively, but I think 70 worked fine too, so it doesn’t appear to stop at the frequency for 55.

I am seeing this problem with PVR-150, PVR-250, and PVR-500 cards, in two different physical locations (miles apart), but using the same Time Warner cable provider (San Diego). It is consistent. No luck with those channels over the last 4 days.

Is it the IVTV driver or the Hauppauge cards? I bought them all in the last 2 months, and there are a variety of tuners (TCL, Phillips, Samsung, and LG) on these cards. I believe I’ve tested with all of those varieties. The Tuner appears NOT to be the variable. The picture seems to be fine as well, using the Hauppauge cards.

I have not yet tried one of the Hauppauge cards in Windows Media Center, so yes I will do that next and let you know.