[mythtv-users] HVR-950q analog/NTSC capture has no sound

[Devin Heitmueller]

On Thu, Feb 9, 2017 at 11:58 AM, James Miller <gajs-f0el at dea.spamcon.org> wrote:
> MythTV 0.27 installed under Gentoo with ALSA-only sound configured, kernel
> 3.18.25. Acquired a couple of these tuners (used) recently. Set up one of
> them, without any hitches whatsoever, to record ATSC: it's been working
> great. Decided to experiment with the other, hoping to capture some analog
> broadcasting from a DTA. Tried ffmpeg capture, viewing with mpv, vlc, and
> MythTV (set up as analog capture card under the latter) using various
> iterations of suspected audio hardware specification: I get no sound in any
> of those configurations--only video gets captured.
>
> The clue that makes most sense to me as an explanation was found in the
> thread https://lists.gt.net/mythtv/users/450443 in a comment made by Devin
> ('Bear in mind we're talking about the ALSA *capture* device built into the
> HVR-950q, not the sound card that you output to. You can run "arecord -l" to
> determine which capture device is the 950q'). Devin's suggestion to run
> arecord -l to find out the ALSA designation for the card's audio component
> results in no detection of any sort of sound device associated with either
> of the HVR-950q's attached to my system; only the onboard audio chip in my
> Liva X gets listed. Same results looking at /proc/asound/cards under
> alsamixer. So, if I'm understanding correctly what's at stake here, the
> analog sound hardware for this device is somehow not detected/configured on
> my system, so of course I cannot capture any sound to go along with the
> analog video I am able to capture from it.

Did you build your kernel from source?  If so, do you have the
snd-usb-audio driver enabled (which is required for ALSA capture from
the HVR-950q)?

If so, would recommend you do a lsmod and see if snd-usb-audio is
being loaded.  Would also be useful to see the full output from dmesg,
since that will give us some indication as to whether the onboard
audio is detected.

Devin
-- 
Devin J. Heitmueller - Kernel Labs
http://www.kernellabs.com