[pulseaudio-discuss] Problem to receive RTP stream from ffmpeg

[Antoine Vacher]

Hello,

I struggle to perform my house audio setup. Let me explain:

I have at home a raspberry pi with a USB microphone running under raspbian. Pulseaudio is not (and cannot) be installed on it. I stream the microphone with ffmpeg with the following command:

arecord -D pcm.duplex -c2 -r 48000 -f S32_LE -t wav -V mono | avconv -i - -acodec libmp3lame -b 32k -f rtp rtp://225.5.5.5:1234/4

The streaming works correctly as I can listen to the audio from my laptop with the following command:

ffplay rtp://225.5.5.5:1234

Now I have a home server where I have a tool that needs to use "rec" to work. Therefore I want to create a RTP source for the RTP stream and forward it to "rec" as default input.

I checked with cli-visualizer script (configured for pulseaudio) and the following command works on the home server:

ffplay rtp://225.5.5.5:1234 -nodisp

Pulseaudio runs in system mode on the server, I tried to create a RTP source in /etc/pulse/system.pa by adding

load-module module-null-sink sink_name=rtp
load-module module-rtp-recv sink=rtp sap_address=225.5.5.5
set-default-source rtp.monitor

There is no speakers on the server so I cannot verify if sound is played, however if I run cli-visualizer then there is no activity so my guess is that RTP stream is not captured by pulseaudio.

Do you see what I miss?

There is a lot of tutorials to stream RTP *from* pulseaudio, but there is a lot less help to send a RTP stream *to* pulseaudio that is not coming from another pulseaudio.

Thanks!

Antoine

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Antoine Vacher
mail/jabber: antoine.vacher at tigre-bleu.net