[alsa-devel] ALSA patch Nvidia 8 channel hdmi audio

Takashi Iwai tiwai at suse.de
Wed Jun 3 13:02:28 CEST 2009


At Wed, 3 Jun 2009 18:25:09 +0800,
Wei Ni wrote:
> 
> Hi, Alan
> 
> I reproduced this problems with speaker-test. The channels are wrong
> mapped.
> 
> It's strange that if use mplayer to run, it looks ok.
> 
> I'm looking this problems, and try to find the root cause.

Actually, from historical reasons, the standard ALSA channel mapping
for 5.1 is
    FL/FR/RL/RR/C/LFE
while Windows sets FL/FR/C/LFE/RL/RR.  If you play a WAV file assuming
the latter channel assignment, it will be played like that.

Does the nvidia codec support channel-slot assignment (verb 0x734)?
If yes, we can assign the channels freely to fix this...


thanks,

Takashi


> 
>  
> 
> Thanks
> 
>  
> 
> From: Alan Alan [mailto:alanwww1 at gmail.com] 
> Sent: Wednesday, June 03, 2009 4:00 PM
> To: Wei Ni
> Cc: Marek Vasut; alsa-devel at alsa-project.org; Peer Chen
> Subject: Re: ALSA patch Nvidia 8 channel hdmi audio
> 
>  
> 
> Hello Wei !
> 
> Thanks for replying.
> I tested it with speaker-test and xbmc babylon. Both had problems with
> channel mapping.
> I used this command:
> 
> speaker-test -Dhdmi -c6
> or
> speaker-test -Dhdmi -c8
> 
> alternatively you could try 
> 
> speaker-test -Dhw:0,3 -c6
> 
> 
> I had to rund Xorg first and have the command from an xterm, becasue
> from a normal terminal it would not work.
> I think that is normal as a limitation of hdmi.
> 
> What about the support for 24bits 192khz sound ?
> 
> speaker-test -Dhdmi -c6  -r192000 does not work.
> 
> Thanks for working on this.
> 
> 
> 
> 
> 
> 2009/6/3 Wei Ni <wni at nvidia.com>
> 
> Hi, Marek and Alan
> I'm a Nvidia engineer and develop this patch file.
> 
> I used mplayer to test. The channels are mapped good.
> Running mplayer -ao alsa:device=hw=0.3 6ch.wav
> 
> I tried to use speaker-test to test, but I can't get the hdmi device
> name.
> I used speaker-test -Dsurround51:NVidia -c6, the sound output from the
> analog jack.
> Which device name should I use?
> 
> I use aplay -l, it show
> **** 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
> 
> Thanks
> Wei.
> 
> 
> -----Original Message-----
> From: Marek Vasut [mailto:marek.vasut at gmail.com]
> Sent: Wednesday, June 03, 2009 8:01 AM
> To: Alan Alan
> Cc: alsa-devel at alsa-project.org; Wei Ni
> Subject: Re: ALSA patch Nvidia 8 channel hdmi audio
> 
> On Wednesday 03 of June 2009 00:30:04 Alan Alan wrote:
> > Thank's for the info.
> > How can i contact him ?
> 
> He and alsa-devel mailing list are both in CC already, please preserve
> them
> there or fix your mailer.
> >
> >
> > 2009/6/3 Marek Vasut <marek.vasut at gmail.com>
> >
> > > I'm not the author of the patch, CCing alsa-devel and the original
> > > author.
> > >
> > > On Tuesday 02 of June 2009 23:58:26 Alan Alan wrote:
> > > > Hi Marek !
> > > >
> > > > I just read your emailing with nvidia devs about alsa supporting 8
> > >
> > > channel
> > >
> > > > lpcm over hdmi.
> > > >
> > > > I checked it out an i have to tell it is working awsome, except
> for a
> > > > few bugs:
> > > >
> > > > The channels are wrong mapped. Running a speakertest -Dhdmi -c6
> gives
> > > > the following result (first where it should sound)
> > > > FL - FL
> > > > C - RL
> > > > FR - FR
> > > > RR - LFE
> > > > RL - C
> > > >
> > > > The other thing i realized that playback is limited to 16 bits 48
> khz.
> > > > I think the minimum which is supported by nvidia hardware is
> 24bits 96
> > > > (or 192) khz.
> > > > Why not ?
> > > >
> > > > Could you contact the devs as i don't know how to reach them.
> > > >
> > > > ps.: Mybe my build methot was not 100% ok ? I used 1.020 Alsa with
> the
> > > > oatched nvidia.c file. Anyway the amplifier shows multichannel
> LPCM and
> > > > that's great news.
> 
> 
> 
> 
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