[mythtv-users] Ghosted Audio

[David Watkins]

On 24/11/05, David Aquilina <dwaquilina at gmail.com> wrote:
> Greetings all,
>
> I'm fairly new to MythTV and am experiencing an occasional problem
> with ghosting audio. When viewing some previously recorded shows, if
> something else is being recorded at the same time I'll hear the audio
> from the new recording in addition to the previously recorded show's
> audio. Worst yet, it's not a simple pass-through - it appears to
> actually be incorporated in the recording and replays exactly the same
> each time the recording is played.
>
> Has anyone encountered this before?
>
> Unfortunately, it's not consistent at all. It's most commonly
> encountered while watching a recording while something else is being
> recorded at the same time, however it doesn't always happen under
> those circumstances. It seems to always occur when I attempt to watch
> something as it's being recorded.
>
> No settings have been changed between shows with correct audio and
> shows with ghosted audio being recorded. For that matter, the system
> has not even been rebooted between those shows nor any of the myth
> components restarted.
>
> I am using:
>
> - MythTV .18 as pulled from
> http://svn.mythtv.org/svn/branches/release-0-18-fixes/mythtv on
> November 22nd
> - Fedora Core 4 (kernel 2.6.14-1.1637_FC4) (x86, NOT x86_64)
> - A WinTV bttv capture card
> - A Yamaha YMF724 sound card. It both records from the bttv card and
> outputs to the speakers.
> - The system is a 1.6Ghz Sempron64 with 512M memory, nForce3-based
> motherboard, and an 80G ATA hard drive.
>
> Any suggestions would be greatly appreciated. If more information is
> needed, please let me know and I'd be happy to provide any other
> details I might have missed.

Well you could play with the mixer, and make sure that all unused
inputs and outputs are muted, particularly the mic input which would
the most prone to picking up unwanted signals.

In the mixer and in mythtvsetup make sure the recording and playback
gains are sensible.  eg you're not recording sound at a very low
level, and then playing back at a very high gain.

Remove any unused external leads that might be plugged into your sound
card - they can act as little aerials.

Move the sound card to a slot far away from the capture card.


I must admit none of the above seem very likely - you may just have
faulty hardware.

Hope this helps