nvidia initial sound being skipped

nvidia initial sound being skipped

[David Shirley]

Hi Developers,

I am using an nvidia MCP78 to connect to a Denon 1910 AVR via HDMI.

I was using Kernel 2.6.32.21 and noticed that the initial few seconds
of my songs was being chopped off.

After seeing http://www.spinics.net/lists/alsa-devel/msg29408.html I
upgraded to 2.6.35.8 (which has that fix in it) and the problem was
been reduced considerably.

But it is still occurring to some extent.

So to see if the HDMI was the problem I changed it to coax spdif - no
change/same problem.

Now I think it could be mplayer, so I try audacious - no change/same problem.

Now I think it could be the flac file/decoding, so I decode the flac
to wav and use aplay - no change/same problem.

The ONLY way I can get the first 0.5seconds of the file to play is by
using audacious and then MANUALLY rewinding (by dragging the scroll
bar thingy) back to the start... then it will play (on either flac or
wav)

Co-incidentally when I do this I get the following error message
dumped to console:
alsa: snd_pcm_prepare failed: Device or resource busy.

I hope someone can help :)

I am happy to get debug or whatever - just let me know what you need!

mythtv@crystal:~$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: NVidia [HDA NVidia], device 0: ALC1200 Analog [ALC1200 Analog]
 Subdevices: 1/1
 Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 1: ALC1200 Digital [ALC1200 Digital]
 Subdevices: 1/1
 Subdevice #0: subdevice #0
card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
 Subdevices: 1/1
 Subdevice #0: subdevice #0

lspci -vvvv
00:07.0 Audio device: nVidia Corporation MCP72XE/MCP72P/MCP78U/MCP78S
High Definition Audio (rev a1)
       Subsystem: ASUSTeK Computer Inc. M3N72-D
       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 11
       Region 0: Memory at fe020000 (32-bit, non-prefetchable) [size=16K]
       Capabilities: [44] Power Management version 2
               Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
PME(D0-,D1-,D2-,D3hot+,D3cold+)
               Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
       Kernel driver in use: HDA Intel

Cheers
David

Re: nvidia initial sound being skipped

[David Shirley]

Hi All,

I just want to say I upgraded to kernel 2.6.36 today and still miss
the first 0.5seconds or so of the sound output.

Again I have ruled out player - mplayer, aplay and audacious all do it

I have ruled out source format - both flac and the wav decoded version
have the same problem.

I have also ruled out physical connection to the AVR, both HDMI and
SPDIF exhibit the same problem.

Any ideas?

Cheers
Dave

On 16 November 2010 20:57, David Shirley <tephra@gmail.com> wrote:
> Hi Developers,
>
> I am using an nvidia MCP78 to connect to a Denon 1910 AVR via HDMI.
>
> I was using Kernel 2.6.32.21 and noticed that the initial few seconds
> of my songs was being chopped off.
>
> After seeing http://www.spinics.net/lists/alsa-devel/msg29408.html I
> upgraded to 2.6.35.8 (which has that fix in it) and the problem was
> been reduced considerably.
>
> But it is still occurring to some extent.
>
> So to see if the HDMI was the problem I changed it to coax spdif - no
> change/same problem.
>
> Now I think it could be mplayer, so I try audacious - no change/same problem.
>
> Now I think it could be the flac file/decoding, so I decode the flac
> to wav and use aplay - no change/same problem.
>
> The ONLY way I can get the first 0.5seconds of the file to play is by
> using audacious and then MANUALLY rewinding (by dragging the scroll
> bar thingy) back to the start... then it will play (on either flac or
> wav)
>
> Co-incidentally when I do this I get the following error message
> dumped to console:
> alsa: snd_pcm_prepare failed: Device or resource busy.
>
> I hope someone can help :)
>
> I am happy to get debug or whatever - just let me know what you need!
>
> mythtv@crystal:~$ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: NVidia [HDA NVidia], device 0: ALC1200 Analog [ALC1200 Analog]
>  Subdevices: 1/1
>  Subdevice #0: subdevice #0
> card 0: NVidia [HDA NVidia], device 1: ALC1200 Digital [ALC1200 Digital]
>  Subdevices: 1/1
>  Subdevice #0: subdevice #0
> card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
>  Subdevices: 1/1
>  Subdevice #0: subdevice #0
>
> lspci -vvvv
> 00:07.0 Audio device: nVidia Corporation MCP72XE/MCP72P/MCP78U/MCP78S
> High Definition Audio (rev a1)
>        Subsystem: ASUSTeK Computer Inc. M3N72-D
>        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 11
>        Region 0: Memory at fe020000 (32-bit, non-prefetchable) [size=16K]
>        Capabilities: [44] Power Management version 2
>                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA
> PME(D0-,D1-,D2-,D3hot+,D3cold+)
>                Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
>        Kernel driver in use: HDA Intel
>
> Cheers
> David
>

Re: nvidia initial sound being skipped

[Clemens Ladisch]

David Shirley wrote:
> > I am using an nvidia MCP78 to connect to a Denon 1910 AVR via HDMI.
> >
> > I was using Kernel 2.6.32.21 and noticed that the initial few seconds
> > of my songs was being chopped off.
> 
> I just want to say I upgraded to kernel 2.6.36 today and still miss
> the first 0.5seconds or so of the sound output.
> ...
> both HDMI and SPDIF exhibit the same problem.

Apparently, your receiver needs even more time to detect that some
sound is playing; there's nothing that the computer could do about it.

Try playing some silence before starting playing music.  (This requires
a software mixer like dmix or PulseAudio.)


Regards,
Clemens

Re: nvidia initial sound being skipped

[David Shirley]

Yeah it could be that. How would u setup a dmix to play silence?

Thanks
D.
On 19/11/2010 7:07 PM, "Clemens Ladisch" <clemens@ladisch.de> wrote:
> David Shirley wrote:
>> > I am using an nvidia MCP78 to connect to a Denon 1910 AVR via HDMI.
>> >
>> > I was using Kernel 2.6.32.21 and noticed that the initial few seconds
>> > of my songs was being chopped off.
>>
>> I just want to say I upgraded to kernel 2.6.36 today and still miss
>> the first 0.5seconds or so of the sound output.
>> ...
>> both HDMI and SPDIF exhibit the same problem.
>
> Apparently, your receiver needs even more time to detect that some
> sound is playing; there's nothing that the computer could do about it.
>
> Try playing some silence before starting playing music. (This requires
> a software mixer like dmix or PulseAudio.)
>
>
> Regards,
> Clemens

Re: nvidia initial sound being skipped

[Clemens Ladisch]

David Shirley wrote:
> How would u setup a dmix to play silence?

If you haven't create or modified /etc/asound.conf or ~/.asoundrc,
dmix should be enabled by default.  (If PulseAudio is installed
correctly, PA should be enabled by default.)

Try this to play ten seconds of silence:

  aplay -d 10 -t raw -f dat /dev/zero

To play continuously, omit the "-d 10".


Regards,
Clemens

Re: nvidia initial sound being skipped

[David Shirley]

OK that works!

But I am concerned about the loss of audio quality when using dmix..

Apart from the sample rate mismatch (and therefor resampling, which
can be avoided by using the correct rate in asound.rc) is there
anything else I should be worried about?

Cheers
D.

On 19 November 2010 22:31, Clemens Ladisch <clemens@ladisch.de> wrote:
> David Shirley wrote:
>> How would u setup a dmix to play silence?
>
> If you haven't create or modified /etc/asound.conf or ~/.asoundrc,
> dmix should be enabled by default.  (If PulseAudio is installed
> correctly, PA should be enabled by default.)
>
> Try this to play ten seconds of silence:
>
>  aplay -d 10 -t raw -f dat /dev/zero
>
> To play continuously, omit the "-d 10".
>
>
> Regards,
> Clemens
>

Re: nvidia initial sound being skipped

[Clemens Ladisch]

David Shirley wrote:
> But I am concerned about the loss of audio quality when using dmix..
> 
> Apart from the sample rate mismatch (and therefor resampling, which
> can be avoided by using the correct rate in asound.rc) is there
> anything else I should be worried about?

x + 0 = x


Regards,
Clemens

Re: nvidia initial sound being skipped

[David Shirley]

Does that mean that dmix/alsa doesn't introduce or loose any bits when
the input rate matches the output rate?

Cheers
D.

On 22 November 2010 18:53, Clemens Ladisch <clemens@ladisch.de> wrote:
> David Shirley wrote:
>> But I am concerned about the loss of audio quality when using dmix..
>>
>> Apart from the sample rate mismatch (and therefor resampling, which
>> can be avoided by using the correct rate in asound.rc) is there
>> anything else I should be worried about?
>
> x + 0 = x
>
>
> Regards,
> Clemens
>

Re: nvidia initial sound being skipped

[Clemens Ladisch]

David Shirley wrote:
> Does that mean that dmix/alsa doesn't introduce or loose any bits when
> the input rate matches the output rate?

In that case, the resample plugin is skipped.


Regards,
Clemens