[mythtv] Tinny audio in some Hauppauge PVR recordings

[usleepless at gmail.com]

Hi John,

> A number of people have experienced "tinny audio" (low volume, clipped
> sound) on some recordings (approximately 15-20% are "tinny", the rest
> are normal) made with mythtv and the Hauppauge PVR cards.  This problem
> has been discussed at some length on the ivtv list.  Recently, several
> of us have found that the newest cx25840 firmware prerelease seems to
> have a positive impact on the problem.

first off, let me say i do not have this very problem, nor did i hear
about it before. what i am wondering about: is it all PVR cards? or
only 250s? or just 150/500s?

i am running mythtv on freebsd, with a derivative driver of ivtv. this
driver supported pvr250, i have adapted it to support 150/500s. what i
did was bringing in the cx25840-files of ivtv and integrating them. i
have had my share of audio problems, and ended up working with a fixed
audio standard ( A2-BG i believe ).

this solved my problem, and made channel-changing faster too.
sub-second i believe.

> Previously, the problem could be easily reproduced by running a bash
> script with an infinite loop containing the command
>
> ivtvctl -q0

this apparently sets the audio-input. i have rewritten my changes to
the fbsd-driver a couple of times, and ended up touching none of the
knobs ( chips ) when changing channels. so just change the frequency,
don't touch the soundchips etc.

the question is, how does this help you?  well it does not i assume,
but my point is that ivtv is beautiful, but big. and a lot of stuff is
being reinitialized when changing channels. this might have to do with
teletext-support, which the fbsd-driver does not have, i do not know.

> While viewing a livetv stream in mythtv.
> As of the latest firmware pre-release, it seems that one can no longer
> induce the tinny audio problem directly through ivtvctl.  This was a
> promising development.

audio or video firmware? i am running 0x2050032 and audio: 14264 bytes.

regards,

usleep