Bug 98368

Streaming audio from streams provided by module-http-protocol-tcp is often impossible over wifi for reasons having nothing to do with sustained connection speed.

Over wired ethernet,

$ wget -O - http://server:4714/listen/source/alsa_output.pci-0000_00_07.0.analog-stereo.monitor >/dev/null

goes at around 180KiB/s, so that's the speed it needs to go at to sustain the stream. When I do the same thing over wifi, I only get a speed of around 100KiB/s—not fast enough. I tested this same wifi connection using an HTTP stream between the same two hosts and got a sustained speed well in excess of 1.5MiB/s, so the wifi is plenty fast enough.

It must be some kind of queueing problem on the pulseaudio server end—probably send buffer overflows. For instance, I can stream reliably with the following command run on the remote client:

$ ssh server wget -q -O - http://localhost:4714/listen/source/alsa_output.pci-0000_00_07.0.analog-stereo.monitor |aplay -f s16_be -c 2 -r 44100

I'd like the option of increasing the size of this sending buffer, so that I do the same streaming without having to tunnel through ssh. I don't really care how much of an audio delay this incurs, since synchronisation isn't an issue. Even if it were, I'd be OK with adding a corresponding delay to the local audio output to maintain synchronisation. Something like this:

$ pactl load-module module-http-protocol-tcp send-buffer-time=500ms