[alsa-devel] Nodes, Widgets, ELD and Digital Surround 5.1 (HDMI) Output?

[Alexander E. Patrakov]

04.12.2014 15:55, bencoxdev at gmail.com wrote:
> Hi Guys,
>     Thank you for your input it's much appreciated.
>     I have now produced the pulse audio log as suggested and it 
> appears that
> when an attempt to open the Digital Surround 5.1 device, it fails with a
> "No such file or directory" error. Here is a snippet of the log 
> showing the
> error.
> (   0.456|   0.000) D: [pulseaudio] alsa-mixer.c: Looking at profile 
> output:iec958-ac3-surround-51
> (   0.456|   0.000) D: [pulseaudio] alsa-mixer.c: Checking for 
> playback on Digital Surround 5.1 (IEC958/AC3) (iec958-ac3-surround-51)
> (   0.456|   0.000) D: [pulseaudio] alsa-util.c: Trying a52:1 with 
> SND_PCM_NO_AUTO_FORMAT ...
> (   0.456|   0.000) I: [pulseaudio] (alsa-lib)pcm.c: Unknown PCM a52:1
> (   0.456|   0.000) I: [pulseaudio] alsa-util.c: Error opening PCM 
> device a52:1: No such file or directory
> So I guess the next question is what is responsible for producing the
> required device?

This is not the correct device. This is a software encoder that is not 
installed on your computer. It will degrade audio quality by 
compression, eat CPU time, kill PulseAudio for exhausting the real-time 
budget, and is generally not needed on HDMI, because HDMI can transport 
PCM 5.1 streams just fine.

Please see my earlier reply how to force PulseAudio into opening the 
correct HDMI device.

-- 
Alexander E. Patrakov