AES/SPDIF channel status bits in ALSA

AES/SPDIF channel status bits in ALSA

[Petr Kulhavy]

Hi,

is there a way to get the channel status bits information from an AES or 
SPDIF input interface through ALSA and read it in userspace?
I'm trying to solve some issues with the channel status bits sent from a 
custom hardware and finding a way to analyse the channel status info.

Regards
Petr

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Petr Kulhavy, MSc
System Architect

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Re: AES/SPDIF channel status bits in ALSA

[Jaroslav Kysela]

Dne 8.1.2015 v 14:14 Petr Kulhavy napsal(a):
> Hi,
> 
> is there a way to get the channel status bits information from an AES or 
> SPDIF input interface through ALSA and read it in userspace?
> I'm trying to solve some issues with the channel status bits sent from a 
> custom hardware and finding a way to analyse the channel status info.

Look for the IEC958 controls (amixer -c <cardnumber> contents), but most
hardware / drivers do not pass this information.

Some hardware is also able to receive the whole spdif frames - look for
drivers with SNDRV_PCM_FMTBIT_IEC958_SUBFRAME_* types (like cmipci).

				Jaroslav

-- 
Jaroslav Kysela <perex@perex.cz>
Linux Kernel Sound Maintainer
ALSA Project; Red Hat, Inc.