On Tue, 2009-07-14 at 19:30 -0700, Jeff Campbell wrote:
> Hi Andy and others,
>
> I've been away for a few months, but now that I've moved house and
> settled back in at my workbench I'll be back testing the cx18 under
> various conditions and hoping to provide useful feedback.
>
> I noticed the occasional red/grey screen issue with the CATV tuner
> appears to be resolved, based on list traffic, which is great. Good
> work.
>
> I wanted to understand the current status of the VBI/CC support. How
> is this looking?
Jeff,
It's done (mostly). Both PAL and NTSC, both sliced and raw, and sliced
VBI insertion into MPEG-2 PS-type streams ala ivtv (I need someone to
check to see if the PTS is correct for these though). Insertion into TS
streams in ivtv format is not available.
Note the CX23418 firmware imposes a restriction that isn't in the
CX23415/6 firmware: an active video capture must be ongoing or VBI
capture stalls after 4 buffers.
This means at a high level, a capture of VBI must be started this way:
1. Configure VBI settings
2. Start video capture
3. Start VBI capture
Step 3 is handled internally by the cx18 driver, if ivtv format VBI
insertion into the MPEG2 PS-type stream is set.
Note: Insertion into a TS stream would require some experimentation in
getting the CX23418 encoder to actually do the insertion vs. cx18 driver
software.
If you really need sliced VBI insertion into a TS right away, I would
recommend doing it in userspace software that reads from both /dev/video
and /dev/vbi. The VBI buffers come once per video frame. Raw VBI
buffers from /dev/vbi have an incrementing 4 bytes "frame" counter at
the end of the buffer. Sliced VBI buffers from /dev/vbi don't have such
a counter, but also come at a rate of once per frame, and may contain
only 1 empty line if there is no VBI data for that frame.
Regards,
Andy
> Thanks,
>
> -Jeff
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