diff options
| -rw-r--r-- | speakerWatchdog.service | 13 | ||||
| -rwxr-xr-x[-rw-r--r--] | speakerWatchdog.sh | 99 |
2 files changed, 55 insertions, 57 deletions
diff --git a/speakerWatchdog.service b/speakerWatchdog.service new file mode 100644 index 0000000..8a43108 --- /dev/null +++ b/speakerWatchdog.service @@ -0,0 +1,13 @@ +[Unit] +Description=Make sure the Speakers don't go to sleep +After=sound.target + + +[Service] +Type=oneshot +StandardOutput=journal +ExecStart=-/usr/local/bin/speakerWatchdog.sh + +[Install] +WantedBy=default.target + diff --git a/speakerWatchdog.sh b/speakerWatchdog.sh index d78c40a..2597eaf 100644..100755 --- a/speakerWatchdog.sh +++ b/speakerWatchdog.sh @@ -1,65 +1,50 @@ #! /bin/bash -# Workaround for stupd 'powersave' 'feature' of Creative Speakers +# Workaround for stupid 'powersave' 'feature' of Creative Speakers # # SJP 11 Dec 2021 # -# This is just a stub for now +# Record a snippet of default stream: -# Which device is the audio output going to? +# 0 rec -d -n trim 0 .1 stat -# st33v@cr4y:~$ grep RUNNING /proc/asound/card*/pcm*/sub*/status -# /proc/asound/card2/pcm0p/sub0/status:state: RUNNING +# rec sox in record mode +# -d default input +# -n direct output to /dev/null +# trim 0 .1 duration 0.1 second +# stat write info about the audio stream +# 2>&1 redirect stderr to stdout +# | pipe +# grep finds this line: Minimum amplitude: 0.000000 +# | pipe +# awk ruturns just the third word (the number) +#echo hello $USER | systemd-cat -t AlexySayle -p warning +maxAmp=$(rec -d -c1 -n trim 0 .1 stat 2>&1 | grep 'Maximum amplitude' | awk {'print $3'}) +echo Max Amplitude = $maxAmp +if [ "$maxAmp" == "0.000000" ]; then + # if Max amplitude = 0 then we have silence! + if [ -f "/tmp/silencemarker" ] ; then + # There was silence last time we checked, so play the tone + echo Play the sound + play -nq synth 1 sine 40 fade 0.2 0 + rm /tmp/silencemarker + else + touch /tmp/silencemarker + fi +else + if [ -f "/tmp/silencemarker" ] ; then + rm /tmp/silencemarker + fi +fi -# That is fine, but the status remains as 'RUNNING' even after the speakers have turned themselves off... -# So I'm going down the track of periodically sending a 'sound' to a loopback device -# sudo modprobe snd-aloop -# Now aply -l shows a new 'card' called Loopback. +systemd-run --user --on-active=10m /usr/local/bin/speakerWatchdog.sh - -record one second of default stream: - -$ rec -d -n trim 0 1 stat - - rec sox in record mode - -d default input - -n direct output to /dev/null - trim 0 1 duration 1 second - stat - -Output: - -Input File : 'default' (pulseaudio) -Channels : 2 -Sample Rate : 48000 -Precision : 16-bit -Sample Encoding: 16-bit Signed Integer PCM - -In:0.00% 00:00:01.02 [00:00:00.00] Out:48.0k [ | ] Clip:0 -Samples read: 96000 -Length (seconds): 1.000000 -Scaled by: 2147483647.0 -Maximum amplitude: 0.000000 -Minimum amplitude: 0.000000 -Midline amplitude: 0.000000 -Mean norm: 0.000000 -Mean amplitude: 0.000000 -RMS amplitude: 0.000000 -Maximum delta: 0.000000 -Minimum delta: 0.000000 -Mean delta: 0.000000 -RMS delta: 0.000000 -Rough frequency: -2147483648 -Done. - -So if Max amplitude = 0 then we have silence! - -to generate a tone that is not audible: -play -n synth 1 sine 40 fade .2 0 - - play sox alias - -n dummy input file - synth synthesise a sound - sine sine wave [the default, so not strictly necessary] - 40 Hz - fade fade in from zero volume to max volume over 200 msec. - '0' says fade out at end over same period. +#to generate a tone that is not audible: +#play -n synth 1 sine 40 fade .2 0 +# +# play sox alias +# -n dummy input file +# synth synthesise a sound +# sine sine wave [the default, so not strictly necessary] +# 40 Hz +# fade fade in from zero volume to max volume over 200 msec. +# '0' says fade out at end over same period. |