Hi folks - I'm at my wit's end here. I've got a RPi 3 running MythTV and I'm trying to get passthrough audio working via ALSA. OpenMAX works alright but messes up the video, so I want to use ALSA.
I've been following these instructions: https://www.mythtv.org/wiki/Raspberry_P ... _with_ALSA. But they seem to be out of date, or I'm doing something wrong. When I create the bcm2835.conf file, no additional iec958 device appears.
I can see with aplay -l/-L that there is an apparently-unrelated IEC958/HDMI device as part of the standard driver:
bcm2835 ALSA, bcm2835 IEC958/HDMI
Direct hardware device without any conversions
But trying to use it doesn't work. Specifically, I get static and the receiver displays "PCM 2.0" rather than 2-channel Dolby Digital, which is what the file is using. The speaker test works fine with the PCM.
- Is it still required to define the device in this .conf file in order to get passthrough audio? Or should the DEV=1 device work?
- How can I convince this configuration file to be read? Or is it being read and simply not working?
- How can I test this without MythTV? I tried downloading a raw AC/3 file and playing it with mplayer, but I can't spell the output device because there are '='s in the name and that's a reserved character.
I've tried a variety of things, from config.txt settings (specifically hdmi_stream_channels=1 and no_hdmi_resample=1) to fiddling with the MythTV settings and gotten nowhere. i know this must work, but I'm clearly doing something wrong and can't find it.