Bug 414542

Summary: "--spdif --alsa-audio-device iec958" produces no audio
Product: [Applications] kaffeine Reporter: jamie marchant <jamie.marchant>
Component: generalAssignee: Mauro Carvalho Chehab <mchehab>
Status: RESOLVED NOT A BUG    
Severity: normal    
Priority: NOR    
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description jamie marchant 2019-11-26 15:57:19 UTC
NOTES: 

Some of the terms I use are explained in "Additional info" 

Description of problem:

Passing "--spdif --alsa-audio-device iec958" to VLClib(remember Kaffeine is just a front-end) causes no audio to be played. The source is Dolby Digital and the command should send the Dolby to my receiver(this is called "passthrough").

Version-Release number of selected component (if applicable):
2.0.18

How reproducible:

If I start playing any audio with VLC while Kaffeine is playing a video(tested by receiving an ATSC broadcast), sound plays from Kaffeine when VLC is closed and seems to keep working until Kaffeine is closed. I used the GUI in VLC to set it up in a way that matches those arguments, I have also tested VLC with those arguments and it does indeed work correctly. 

Under some rare unreproducible cases, I was able to get a Stereo audio track to play but this was not passthrough(the light was not on).

Steps to Reproduce:
When testing this I used an ATSC broadcast, I have not fully tested other features. 
0. Click the "Settings" menu and click "Configure Kaffeine", in "libVLC" add "--spdif --alsa-audio-device iec958" and then restart Kafffeine 
1. Start a stream that can use SPDIF Passthrough(like receiving an ATSC broadcast) 
2. You will here silence

Actual results:
You will hear silence.(in one case this affected other programs too until Kaffine was closed) 


Expected results:
You here the stream. 


Additional info:
In case you don't know some of the terms I used here:

SPDIF Passthrough: 

Passes non-PCM streams(like Dolby Digital) directly to a decoder(amp or A/V receiver) rather than having the PC decode it. No other sounds can play when you do this. 

ATSC: 
Digital television broadcast in the USA and Canada(maybe other places too), can be received with the correct hardware and software. (Kaffeine is the software) 

The odd thing:
Kafffeine uses VLC as a backend and as I said it works fine.
Comment 1 jamie marchant 2019-11-26 20:22:59 UTC
Had to use a slightly different command as I realized I also told VLC to use ALSA, so now it works fine with this command: 
--spdif --alsa-audio-device iec958 --aout=alsa