ALSA lib pcm_hw.c:1713:(_snd_pcm_hw_open) Invalid value for card
When running play -q -V0 --single-threaded -t sl - synth 00:00:05 whitenoise band -n 1200 200 tremolo 20 .1 < /dev/zero & from PHP, using exec() or shell_exec().
The identical command works perfectly when run directly on the CLI.
I added the www-data user to the audio group just in case, but it didn’t help.
I added the -d option (‘Use the default audio device (where available)’) to my play command, but it didn’t help, and I can’t see any other option to change the device it uses.