[mythtv-users] Audio issues - New Install

John Pilkington J.Pilk at tesco.net
Wed Aug 9 19:50:13 UTC 2017


On 09/08/17 19:54, Ashu Desai wrote:
> 
> 
> On Wed, Aug 9, 2017 at 1:31 PM, Peter Bennett <cats22 at comcast.net 
> <mailto:cats22 at comcast.net>> wrote:
> 
> 
> 
>     On 08/09/2017 02:09 PM, Ashu Desai wrote:
>>     I have a brand new install on CentOS 7.
>>
>>     Backend is a VM and FE is on Zotac Ion
>>
>>     When I open Alsammixer, i get the default one
>>
>>     http://tinypic.com/r/2eldu9s/9
>>
>>     I then press F6 and select the NVidia card
>>
>>     http://tinypic.com/r/rli9ty/9
>>
>>     However, if I press escape and go right back to alsamixer, it
>>     reverts it back to the original one.
>>
>>     lspci -vvnn reveals this for Audio:
>>
>>     00:08.0 Audio device [0403]: NVIDIA Corporation MCP79 High
>>     Definition Audio [10de:0ac0] (rev b1)
>>             Subsystem: PC Partner Limited / Sapphire Technology Device
>>     [174b:437b]
>>             Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV-
>>     VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx-
>>             Status: Cap+ 66MHz+ UDF- FastB2B+ ParErr- DEVSEL=fast
>>     >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
>>             Latency: 0 (500ns min, 1250ns max)
>>             Interrupt: pin A routed to IRQ 22
>>             Region 0: Memory at fae78000 (32-bit, non-prefetchable)
>>     [size=16K]
>>             Capabilities: <access denied>
>>             Kernel driver in use: snd_hda_intel
>>             Kernel modules: snd_hda_intel
>>
>>
>>     [mythtv at mythfe7 ~]$ aplay -l
>>     **** List of PLAYBACK Hardware Devices ****
>>     card 0: NVidia [HDA NVidia], device 0: ALC662 rev1 Analog [ALC662
>>     rev1 Analog]
>>       Subdevices: 1/1
>>       Subdevice #0: subdevice #0
>>     card 0: NVidia [HDA NVidia], device 1: ALC662 rev1 Digital [ALC662
>>     rev1 Digital]
>>       Subdevices: 1/1
>>       Subdevice #0: subdevice #0
>>     card 0: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
>>       Subdevices: 1/1
>>       Subdevice #0: subdevice #0
>>
>>     [mythtv at mythfe7 ~]$ aplay -L
>>     null
>>         Discard all samples (playback) or generate zero samples (capture)
>>     pulse
>>         PulseAudio Sound Server
>>     sysdefault:CARD=NVidia
>>         HDA NVidia, ALC662 rev1 Analog
>>         Default Audio Device
>>     front:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         Front speakers
>>     surround21:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         2.1 Surround output to Front and Subwoofer speakers
>>     surround40:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         4.0 Surround output to Front and Rear speakers
>>     surround41:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         4.1 Surround output to Front, Rear and Subwoofer speakers
>>     surround50:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         5.0 Surround output to Front, Center and Rear speakers
>>     surround51:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         5.1 Surround output to Front, Center, Rear and Subwoofer speakers
>>     surround71:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Analog
>>         7.1 Surround output to Front, Center, Side, Rear and Woofer
>>     speakers
>>     iec958:CARD=NVidia,DEV=0
>>         HDA NVidia, ALC662 rev1 Digital
>>         IEC958 (S/PDIF) Digital Audio Output
>>     hdmi:CARD=NVidia,DEV=0
>>         HDA NVidia, HDMI 0
>>         HDMI Audio Output
>>
>>
>>     Here's my /etc/asound.conf
>>
>>     # Place your global alsa-lib configuration here...
>>     #
>>     pcm.!default {
>>            type hw
>>            card 0
>>            device 3
>>        }
>>     ~
>>     ~
>>
>>     Under Mythfrontend Setup/Audio
>>     I have selected the ALSA:hdmi:Card=NVIDIA:DEV=0 that comes as option
>>
>>     When you do "Test" - everything comes ok except sound for Center
>>     (Comes off Surround Left) & Surround Left (swapped to Center)
>>
>>     I also can't hear audio off quite a few movies, and when I check
>>     my audio receiver shows input as PCM. The ones that have AC3 or
>>     DTS comes out fine (although the sound coming off wrong speakers
>>     irks me)
>>
>>     I am not hearing any TrueHD even though that is checked along with
>>     HBR box that's checked by default
>>
>>     I am giving data that I feel is needed so apologies if it's too
>>     much or too little.
>>     .
>>
>>     I am also hoping alsamixer can change default from PulseAudio to HDMI
>>     I can def give any other info that's required to solve this
>>
>>
> 
>     Check your speaker configuration - 5.1 7.1 or stereo. This can
>     affect which speaker the sounds come out of for PCM. You can try
>     different values and see if anything works,
> 
> 
> I have 5.1
> 
> 
>     Is the audio passed to the sound system via HDMI?
> 
> 
> Yes, HDMI
> 
>     If there is a TOSLINK connection in there, that may affect things,
>     because TOSLINK only supports 2 channels in PCM mode, so if it is
>     sending more than 2 channels they may get lost.
> 
>     If AC3 and DTS is getting to the wrong speakers you must have
>     something else going on, because the sound system itself will be
>     sorting out which track goes to which speaker. (Speaker wires crossed?)
> 
> 
> When I give the cli command "speaker-test...." audio comes out perfectly 
> like it's supposed to.
> 
>     Note that the audio system test uses PCM sound. So you cannot test
>     how AC3 will work that way. You say that the audio system test works
>     but PCM movies don't work. That does not make sense.
> 
>     If PCM does not work at all you can get past it by selecting
>     "Upconvert stereo to 5.1 surround". That will convert PCM audio to
>     Dolby Digital (AC3).
> 
> 
> I already have it checked.
> 
> Is there a way to fix the alsamixer thing? It somehow keeps showing 
> default as Pulse and doesn't seem to retain my changes after I press esc
> 

I have only a stereo-via-hdmi setup with a nvidia GT 710 card.  At 
present I'm using the 340.102 driver and Fedora 25.  I haven't knowingly 
done anything with alsa or pulse.

ALSA:hdmi:CARD=NVidia,DEV=1 , selected from the frontend setup wizard, 
works with myth, and with vlc when selected as its audio device.  DEV=0 
doesn't, but is selected by SMplayer which seems to offer no other hdmi 
option.  Just FYI

John





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