[mythtv-users] HDMI ac3 passthough audio

Thu Feb 12 16:46:24 UTC 2009

On Thu, Feb 12, 2009 at 8:28 AM, James Crow <james at ultratans.com> wrote:
> On Thu, 2009-02-12 at 08:36 -0700, Joel Means wrote:
>> On Thu, Feb 12, 2009 at 8:11 AM, Joel Means <means.joel at gmail.com> wrote:
>> > Just one last update from me.  I updated to ALSA 1.0.19 with no luck.
>> > I will also point out that I have tried all of this with and without
>> > Pulseaudio installed.  I have a feeling that Abit just screwed up
>> > their implementation of this chipset, since it seems to work fine for
>> > other people on Asus motherboards.  The sad thing is that I bought
>> > this motherboard specifically for the HDMI port and took a long while
>> > to decide between Abit and Asus.  In the end, I let ~$20 decide for
>> > me.  Oh, well.  Live and Learn.
>> > Joel
>> >
>>
>> One other note and questions on this.  I did note that with the
>> installation of ALSA 1.0.19, I have an additional entry in the output
>> of 'aplay -L' which wasn't there before.  Now, the last three entries
>> are:
>>
>> iec958:CARD=NVidia,DEV=0
>>     HDA NVidia, ALC888 Digital
>>     IEC958 (S/PDIF) Digital Audio Output
>> hdmi:CARD=NVidia,DEV=0
>>     HDA NVidia, NVIDIA HDMI
>>     HDMI Audio Output
>> null
>>     Discard all samples (playback) or generate zero samples (capture)
>>
>> Before, I didn't have the hdmi entry.  I could, however, use "hdmi" as
>> an output device for speaker-test or mplayer and get sound over hdmi.
>> It just wasn't listed here.  I am wondering if someone who has the
>> same ALC888 controller (preferably with the GeForce 7050 chipset) and
>> has AC3 passthrough over HDMI working can post their output of 'aplay
>> -L'.  The reason I ask is that mine lists iec958 as being a Digital
>> Audio Output, but hdmi is only listed as being Audio Output.  I don't
>> know if that is relevant or not, but I would be interested in seeing
>> what another mobo has to say about it.
>> Thanks,
>>
>> Joel
>
> >From my Asus M2N68 with HDMI and onboard SPDIF out:
>
> ~$ uname -r
> 2.6.27-11-generic
>
> $ aplay -l
> **** List of PLAYBACK Hardware Devices ****
> card 0: NVidia [HDA NVidia], device 0: VT1708B Analog [VT1708B Analog]
>  Subdevices: 2/2
>  Subdevice #0: subdevice #0
>  Subdevice #1: subdevice #1
> card 0: NVidia [HDA NVidia], device 3: NVIDIA HDMI [NVIDIA HDMI]
>  Subdevices: 1/1
>  Subdevice #0: subdevice #0
>
>
> $ aplay -L
> default:CARD=NVidia
>    HDA NVidia, VT1708B Analog
>    Default Audio Device
> front:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    Front speakers
> surround40:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    4.0 Surround output to Front and Rear speakers
> surround41:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    4.1 Surround output to Front, Rear and Subwoofer speakers
> surround50:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    5.0 Surround output to Front, Center and Rear speakers
> surround51:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    5.1 Surround output to Front, Center, Rear and Subwoofer speakers
> surround71:CARD=NVidia,DEV=0
>    HDA NVidia, VT1708B Analog
>    7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
> null
>    Discard all samples (playback) or generate zero samples (capture)
>
> This is the same Ubuntu 8.10 system that had HDMI audio (not ac3
> passthrough) working. I updated Ubuntu and the new kernel overwrote my
> updated alsa drivers. I then reran the Alsa upgrade script and got back
> my 1.0.19 driver. I am unable to test because I do not have any HDMI
> display device near the computer.
>
> If I try to play a file with ac3 audio using hw passthrough this is what
> I get:
> :~/Desktop$ mplayer -ao alsa:device=hw=0.3 -ac hwac3 -vf pp=fd
> 4032_20090120114500.mpg
> MPlayer 1.0rc2-4.3.2 (C) 2000-2007 MPlayer Team
> CPU: AMD Athlon(tm) X2 Dual Core Processor BE-2400 (Family: 15, Model:
> 107, Stepping: 2)
> CPUflags:  MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 1 SSE2: 1
> Compiled with runtime CPU detection.
> mplayer: could not connect to socket
> mplayer: No such file or directory
> Failed to open LIRC support. You will not be able to use your remote
> control.
>
> Playing 4032_20090120114500.mpg.
> TS file format detected.
> VIDEO MPEG2(pid=2176) AUDIO A52(pid=2177) NO SUBS (yet)!  PROGRAM N. 1
> VIDEO:  MPEG2  1920x1080  (aspect 3)  29.970 fps  25000.0 kbps (3125.0
> kbyte/s)
> vo: couldn't open the X11 display ()!
> Error opening/initializing the selected video_out (-vo) device.
> ==========================================================================
> Forced audio codec: hwac3
> Opening audio decoder: [hwac3] AC3/DTS pass-through S/PDIF
> No accelerated IMDCT transform found
> hwac3: switched to AC3, 384000 bps, 48000 Hz
> AUDIO: 48000 Hz, 2 ch, ac3, 384.0 kbit/25.00% (ratio: 48000->192000)
> Selected audio codec: [hwac3] afm: hwac3 (AC3 through S/PDIF)
> ==========================================================================
> [AO_ALSA] alsa-lib: conf.c:3843:(parse_args) Unknown parameter AES0
> [AO_ALSA] alsa-lib: conf.c:3969:(snd_config_expand) Parse arguments
> error: No such file or directory
> [AO_ALSA] alsa-lib: pcm.c:2202:(snd_pcm_open_noupdate) Unknown PCM
> hw:0,3,AES0=6
> AO: [alsa] 48000Hz 2ch ac3 (1 bytes per sample)
> Video: no video
> Starting playback...
> A:44742.1 (12:25:42.0) of 387863.9 (107:44:23.8)  0.5%
> Exiting... (Quit)
>
> Again, I don't know if that helps or not.
>
> Cheers,
> James
>
>
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>

I think you are saying that you tried the above without a HDMI device
hooked up so it would not surprise me that it didn't work.  Nothing
HDMI that I have will play without negotiating between the source and
sink.  That said, it looks like you are doing the right things.
Please let me know if you try (or tried) this with an HDMI TV
connected.

Allen