[pulseaudio-discuss] Underrunning null sink

[Travis Brown]

After digging into this a bit more, it appears that the latency on the null sink is all over the place when pavucontrol is NOT running.  For example, here is a case when it is not running:

        index: 2
	name: <ip_mcast>
	driver: <module-null-sink.c>
	flags: DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
	state: IDLE
	suspend cause:
	priority: 1000
	volume: mono: 65536 / 100% / 0.00 dB
	        balance 0.00
	base volume: 65536 / 100% / 0.00 dB
	volume steps: 65537
	muted: no
	current latency: 1147.05 ms
	max request: 62 KiB
	max rewind: 62 KiB
	monitor source: 3
	sample spec: s16le 1ch 16000Hz
	channel map: mono
	             Mono
	used by: 0
	linked by: 0
	configured latency: 2000.00 ms; range is 0.50 .. 2000.00 ms
	module: 4
	properties:
		device.description = "ip_mcast"
		device.class = "abstract"
		device.icon_name = "audio-card”


When pavucontrol is running, I get much more reasonable latencies (20-30mS).   

  index: 2
	name: <ip_mcast>
	driver: <module-null-sink.c>
	flags: DECIBEL_VOLUME LATENCY DYNAMIC_LATENCY
	state: IDLE
	suspend cause:
	priority: 1000
	volume: mono: 65536 / 100% / 0.00 dB
	        balance 0.00
	base volume: 65536 / 100% / 0.00 dB
	volume steps: 65537
	muted: no
	current latency: 20.63 ms
	max request: 1 KiB
	max rewind: 1 KiB
	monitor source: 3
	sample spec: s16le 1ch 16000Hz
	channel map: mono
	             Mono
	used by: 0
	linked by: 1
	configured latency: 40.00 ms; range is 0.50 .. 2000.00 ms
	module: 4
	properties:
		device.description = "ip_mcast"
		device.class = “abstract"


The biggest thing I notices is obviously the max request size. pavucontrol probably sets that to 1 KiB and restores it to 62 KiB when it exists.  Is this something that can be changed from a config file?

Thanks again,
Travis