[mythtv-users] Can't get audio to work on frontend

Bobby Gill brownitus at gmail.com
Thu Dec 2 22:21:37 UTC 2010 

> Please post the result of :
>
> aplay -l
>
>
└─> aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Revolution71 [M Audio Revolution-7.1], device 0: ICE1724 [ICE1724]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 0: Revolution71 [M Audio Revolution-7.1], device 1: ICE1724 IEC958
[ICE1724 IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: Revolution71 [M Audio Revolution-7.1], device 2: ICE1724 Surrounds
[ICE1724 Surround PCM]
  Subdevices: 3/3
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2



> and
> aplay -L
>
>
 └─> aplay -L
null
    Discard all samples (playback) or generate zero samples (capture)
front:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    Front speakers
rear:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724 Surround PCM
    Rear speakers
center_lfe:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724 Surround PCM
    Center and Subwoofer speakers
side:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724 Surround PCM
    Side speakers
surround40:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    4.0 Surround output to Front and Rear speakers
surround41:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=Revolution71,DEV=0
    M Audio Revolution-7.1, ICE1724
    IEC958 (S/PDIF) Digital Audio Output

Your default ALSA device points to ALSA:duplex, which points to
> ALSA:dmix6 which points to ALSA:hw:0,0". Talk about a complicated alsa
> config ! And buggy as that.
> You have two definitions of the pcm.default device in there, with the
> 2nd one referring to plugequal -> dmix6 -> hw:0,0
>
> From looking at your asound.conf, what it does is downmix 5.1 to
> stereo but it's a very basic downmixing.
>
> Myth can do upmixing and downmixing for you with much higher quality
> algorithms.
>
> Myth doesn't show the other audio device, because they are all in use.
> Make sure when running mythfrontend that you turn off any application
> using audio ...
>
>
Ahh, see way back when I sought help in #alsa in IRC I just could not get my
5.1 surround to work and someone helped me but it was slightly convoluted I
suppose, I never changed it since then (if it ain't broke...). Slightly off
the topic but is there alteration to my asound.conf that would enhance my
sound that you could help me with? Again in case the link is:
http://pastebin.ca/2008380.

Also, I absolutely must work around that limitation of having to shut down
any audio before running mythfrontend. Myself and others in my family use my
machine and it's not feasible much of the time to leave mythfrontend
running, nor to shutdown firefox (lsmod shows it using sound all the time it
runs with any flash), etc. I've had working mixing no matter how many apps
running before, really need to get that going again!!



> You can override the myth auto-settings, type in the audio device:
> ALSA:hw:0,0
>
> make sure AC3 and DTS are unchecked if the fields appear, and set it to
> Stereo
>
> This will let myth do the downmixing, you will get a much better
> result than using your alsa dmix
>
> If you want to use your original dmix (ALSA:default) you will need to
> set up the speaker as 5.1 because of how you've configured ALSA.
>
>
Okay, I put in ALSA:hw:0,0 as indicated and now the sound works (after
shutting down every app using sound):

2010-12-02 17:05:13.974 TV: Attempting to change from None to
WatchingPreRecorded
2010-12-02 17:05:14.079 AudioPlayer: Disabling Audio, params(0,2,44100)
2010-12-02 17:05:14.226 AudioOutput Error: Aborting Audio Reconfigure.
Invalid audio parameters ch 2 fmt 0 @ 44100Hz
2010-12-02 17:05:14.226 AudioPlayer: Disabling Audio, reason is: Aborting
Audio Reconfigure. Invalid audio parameters ch 2 fmt 0 @ 44100Hz
2010-12-02 17:05:14.226 playCtx, Error: Aborting Audio Reconfigure. Invalid
audio parameters ch 2 fmt 0 @ 44100Hz
2010-12-02 17:05:14.322 AFD Warning: ScanATSCCaptionStreams() called with no
PMT
2010-12-02 17:05:14.322 AFD: Opened codec 0xa43053e0, id(MPEG2VIDEO)
type(Video)
2010-12-02 17:05:14.322 AFD: codec MP2 has 2 channels
2010-12-02 17:05:14.322 AFD: Opened codec 0xa4302800, id(MP2) type(Audio)
2010-12-02 17:05:14.420 AO: Opening audio device 'hw:0,0' ch 2(2) sr 48000
sf signed 32 bit reenc 0
2010-12-02 17:05:14.420 Opening ALSA audio device 'hw:0,0'.
2010-12-02 17:05:14.424 AudioPlayer: Enabling Audio
2010-12-02 17:05:14.504 Clearing OpenGL painter cache.
2010-12-02 17:05:14.578 VDPAU: Created 2 output surfaces.
2010-12-02 17:05:14.578 VDPAU: Version 1
2010-12-02 17:05:14.578 VDPAU: Information NVIDIA VDPAU Driver Shared
Library  260.19.21  Thu Nov  4 20:56:20 PDT 2010
2010-12-02 17:05:14.578 VDPAU: Created VDPAU render device 1920x1200
2010-12-02 17:05:14.591 Player(0): Forcing decode extra audio option on
(Video method requires it).
2010-12-02 17:05:14.602 [mpegvideo_vdpau @ 0xb4cd94a0]warning: first frame
is no keyframe
2010-12-02 17:05:14.679 Player(0): Video timing method: USleep with busy
wait
2010-12-02 17:05:14.680 TV: Changing from None to WatchingPreRecorded
2010-12-02 17:05:14.879 VDPAU: Added 2 output surfaces (total 4, max 4)
2010-12-02 17:05:14.939 ALSA, Error: WriteAudio: buffer underrun
2010-12-02 17:05:16.925 Marking recording as unwatched
2010-12-02 17:05:17.116 TV: Attempting to change from WatchingPreRecorded to
None

Again I'd really appreciate it if you could help in improving my asound.conf
and/or helping me to achieve mixing so that it runs as before without having
to shutdown other apps. Thanks a lot for your help!

Bobby
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