Sound in java: Best practice 2022

snapcraft
1

So, my java application is silent when run as snap. I have added plugs for audio-playback + pulseaudio (and connect it)

Then I found a couple of related threads here, is this still valid in late 2022? (The links seems to be broken though)

2

The java version you use would determine if you need to setup alsa or not, the instructions seem pretty much still valid.

3

I can’t edit the post on the linked thread anymore, the only thing I’d change now is in regards to point 1; it’s been a longtime since the Pulseaudio interface has been deprecated and as of now I’d run with audio-playback and audio-record exclusively.

Otherwise, nothing else has changed since.

Tl;Dr

  • Correct interfaces (audio-playback)
  • Use extensions to get the socket setup
  • If Java 8, stage libpulse (might be in the newest extensions automatically?)
  • If Java 9+, additionally stage alsa, use layouts and ALSA_CONFIG_PATH variable to use alsa-pulse backend.

This isn’t particularly a Java specific problem, the only Java nuance here, is that Java 8 from the Ubuntu/Debian repositories has native Pulseaudio support whereas 9+ do not, and this can be confusing since you’d usually assume newer versions would have more features/compatibility but isn’t true in this specific scenario.

4

I’m aiming for 17 or 19.

5

Thanks @James-Carroll, I’ll give it a try then. :slight_smile:

6

it should be in all extensions (core20/22 at least), there should be no need to stage libpulse nowadays …

7

It works! Now I got sound in my snap. :slight_smile: Not sure of the contents of asound.conf though, should I do anything different?

name: yaya
title: Yaya
base: core22
version: '0.1-SNAPSHOT'
summary: Yet Another Yahtzeeesque Application
description: |
    **TODO write a description
grade: stable
architectures: [ amd64 ]
confinement: strict
icon: snap/gui/yaya.png
license: Apache-2.0

layout:
  /usr/lib/$SNAPCRAFT_ARCH_TRIPLET/alsa-lib:
    bind: $SNAP/usr/lib/$SNAPCRAFT_ARCH_TRIPLET/alsa-lib

apps:
  yaya:
    command: yaya/bin/yaya
    extensions: [gnome]
    plugs:
        - audio-playback
    environment:
      ALSA_CONFIG_PATH: $SNAP/etc/asound.conf

parts:
  yaya:
    plugin: dump
    source: /root/project/yaya-$SNAPCRAFT_PROJECT_VERSION-linux.zip
    source-type: zip
    stage-packages:
      - libasound2
      - libasound2-plugins

  config:
    after:
      - yaya
    plugin: nil
    override-prime: |
        #sed -i 's/${HOME}\/.${APPNAME}/${SNAP_USER_COMMON}\/.yaya/' /root/prime/yaya/bin/yaya
        #sed -i 's/${HOME}\/.cache\/${APPNAME}/${SNAP_USER_COMMON}\/.cache\/yaya/' /root/prime/yaya/bin/yaya
        rm /root/prime/yaya/platform/lib/*.dll
        rm /root/prime/yaya/platform/lib/*.exe
        
  apt:
    plugin: nil
    override-build: |
        apt install openjdk-19-jdk -y

  jlink:
    plugin: nil
    after: [apt]
    override-build: |
        rm -rf $SNAPCRAFT_PRIME/yaya/jre

        jlink --no-header-files \
            --no-man-pages \
            --strip-debug \
            --compress=1 \
            --add-modules java.base,java.datatransfer,java.xml,java.prefs,java.desktop,java.instrument,java.logging \
            --output $SNAPCRAFT_PRIME/yaya/jre

        strip -p --strip-unneeded $SNAPCRAFT_PRIME/yaya/jre/lib/server/libjvm.so

  alsa-pulseaudio:
    plugin: dump
    source: .
    override-pull: |
      mkdir etc -p
      cat > etc/asound.conf <<EOF
      pcm.!default {
          type pulse
          fallback "sysdefault"
          hint {
              show on
              description "Default ALSA Output (currently PulseAudio Sound Server)"
          }
      }
      ctl.!default {
          type pulse
          fallback "sysdefault"
      }
      EOF
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8

I forgot to mention that it’s published now.

yaya_appstream01
yaya_appstream011336Ă—930 307 KB

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