[mythtv-users] Strange Audio Problem 0.25

Wed Jun 13 02:33:10 UTC 2012

On Tue, Jun 12, 2012 at 9:53 PM, Igor Cicimov <icicimov at gmail.com> wrote:
> On Wed, Jun 13, 2012 at 3:40 AM, jr <jraymyth at gmail.com> wrote:
>>
>> I have a fresh install of Ubuntu 12.04 and MythBuntu 0.25 FE/BE.  The
>> install went without a hitch.  The tuners and channels are all
>> configured.  Blah blah blah.  The problem I am having is with the
>> audio.
>>
>> I went through the Setup Wizard and set the audio device
>> (ALSA:hdmi:CARD=NVidia,DEV=1).  The speaker test hissed as expected.
>> Video Playback Profile is set to VDPAU High Quality. Test High
>> Definition plays me a nice movie intro of someone walking across icy
>> mountains.  The incidental music is clear and audible.
>>
>> So I went to make a recording and played it.  The video was clear, but
>> no audio was emitted.  The recording does have sound when played
>> through VLC.  I figure that its a config problem, but of what?  ALSA
>> is clearly working with the HDMI port.  MythTV is communicating with
>> ALSA, in the setup at the least.  I don't mind digging in...but where
>> do I dig?
>>
>> Thanks,
>> jr
>>
>> Intel DQ67EP (i5) -- Onboard audio is disabled in the bios
>> MSI N210-MD512H GeForce 210 512MB
>> 4GB
>>
>>
>> mythuser at Jotun:~$ aplay -l
>> **** List of PLAYBACK Hardware Devices ****
>> card 0: PCH [HDA Intel PCH], device 0: ALC888 Analog [ALC888 Analog]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> card 0: PCH [HDA Intel PCH], device 1: ALC888 Digital [ALC888 Digital]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> card 1: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> card 1: NVidia [HDA NVidia], device 7: HDMI 0 [HDMI 0]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> card 1: NVidia [HDA NVidia], device 8: HDMI 0 [HDMI 0]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> card 1: NVidia [HDA NVidia], device 9: HDMI 0 [HDMI 0]
>>  Subdevices: 1/1
>>  Subdevice #0: subdevice #0
>> _______________________________________________
>> mythtv-users mailing list
>> mythtv-users at mythtv.org
>> http://www.mythtv.org/mailman/listinfo/mythtv-users
>
>
>
> "2012-06-12 19:58:11.009507 E  ALSA: Error opening
> /proc/asound/card1/pcm7p/sub0/prealloc: Permission denied.
> 2012-06-12 19:58:11.009521 E  ALSA: Try to manually increase audio
> buffer with: echo 128 | sudo tee
> /proc/asound/card1/pcm7p/sub0/prealloc
> 2012-06-12 19:58:11.009535 E  ALSA: Unable to sufficiently increase
> ALSA hardware buffer size - underruns are likely
> 2012-06-12 19:58:11.009543 I  ALSA: OpenDevice
> hdmi:CARD=NVidia,DEV=1,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 for
> passthrough"
>
> You might also check the user permissions on /dev/asound directory and if
> the user you are running MythTV with belongs to video and audio groups. I'm
> not an expert in Myth audio but looks like it tries to open the device 7 on
> the Nvidia card for playback?
>
> You might also try to increase the buffer size manually as the error
> suggests. Run
>
> $ echo 4096 > /proc/asound/card1/pcm7p/sub0/prealloc
>
> and see what happens. If the command fails with permissions issue then you
> really have a problem with your Myth user editing the ALSA files. Fix the
> permissions or run the command as root and start the playback again to see
> if things have improved.
>
> Igor
>
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
> http://www.mythtv.org/mailman/listinfo/mythtv-users
>

I added my user to the audio group : usermod -a -G audio mythuser
and did a
echo 4096 > /proc/asound/card1/pcm7p/sub0/prealloc

The overrun and permission denied lines went away. but still no sound
during playback.  No change when running mythfrontend as root.

Is sound managed differently in the Setup Wizard than it is during playback?

***Latest Log***
2012-06-12 22:26:37.674113 I  AFD: Opened codec 0x470ef50, id(AC3) type(Audio)
2012-06-12 22:26:37.674128 I  AFD: Audio Track #2, with type 0 is A/V
stream #2 and has 2 channels in the Spanish; Castilian
language(7565409).
2012-06-12 22:26:37.674143 I  AFD: Trying to select default track
2012-06-12 22:26:37.674148 I  AFD: Trying to select audio track (w/lang)
2012-06-12 22:26:37.674608 I  AFD: Selected track 1: English AC3 2ch
(A/V Stream #1)
2012-06-12 22:26:37.674621 I  AFD: Initializing audio parms from audio track #1
2012-06-12 22:26:37.674639 I  AFD: Audio format changed
			from id(NONE)     -1Hz -1ch -1bps     (profile 0) to id( AC3)
48000Hz  2ch 16bps  pt (profile 0)
2012-06-12 22:26:37.674656 I  AO: Setting AC3 passthrough
2012-06-12 22:26:37.675238 I  SPDIFEncoder: Creating spdif encoder (for AC3)
2012-06-12 22:26:37.675243 I  AO: Killing AudioOutputDSP
2012-06-12 22:26:37.675251 I  AO: Original codec was AC3, signed 16
bit, 48 kHz, 2 channels
2012-06-12 22:26:37.675266 I  AO: enc(0), passthru(1), features
(AC3,DTS) configured_channels(2), 2 channels supported(1)
max_channels(2)
2012-06-12 22:26:37.675278 I  AO: Opening audio device
'hdmi:CARD=NVidia,DEV=1' ch 2(2) sr 48000 sf signed 16 bit reenc 0
2012-06-12 22:26:37.675285 I  ALSA: OpenDevice
hdmi:CARD=NVidia,DEV=1,AES0=6,AES1=0x82,AES2=0x00,AES3=0x01 for
passthrough
2012-06-12 22:26:37.683536 I  ALSA: SetParameters(format=2,
channels=2, rate=48000, buffer_time=500000, period_time=4)
2012-06-12 22:26:37.683615 I  ALSA: Buffer size range from 64 to 1048576
2012-06-12 22:26:37.683625 I  ALSA: Period size range from 32 to 524288
2012-06-12 22:26:37.683652 I  ALSA: Buffer time = 500000 us
2012-06-12 22:26:37.683673 I  ALSA: Period time = 5 periods
2012-06-12 22:26:37.802580 I  ALSA: Buffer size = 24000 | Period size = 4800
2012-06-12 22:26:37.898559 I  AO: Audio fragment size: 9600
2012-06-12 22:26:37.898584 I  AO: Audio Stretch Factor: 1
2012-06-12 22:26:37.898693 I  AO: Ending Reconfigure()
2012-06-12 22:26:37.898723 I  Dec: Selected track #1 in the Unknown language(0)
2012-06-12 22:26:37.898739 I  Dec: Resyncing position map.
posmapStarted = 0 livetv(0) watchingRec(0)
2012-06-12 22:26:37.898851 I  AO: kickoffOutputAudioLoop: pid = 3096
2012-06-12 22:26:37.898874 I  AO: OutputAudioLoop: Play Event
2012-06-12 22:26:37.899499 I  Dec: Position map filled from DB to: 2352
2012-06-12 22:26:37.899516 I  Dec: SyncPositionMap prerecorded, from
DB: 99 entries
2012-06-12 22:26:37.899528 I  Dec: SyncPositionMap, new totframes:
2352, new length: 39, posMap size: 99
2012-06-12 22:26:38.141460 I  AFD: Position map found
2012-06-12 22:26:38.141479 I  AFD: Successfully opened decoder for
file: "/var/lib/mythtv/recordings/1081_20120612111100.mpg". novideo(0)