On Thu, 2018-11-08 at 14:56 +0500, Alexander E. Patrakov wrote: > Mikael Nousiainen <mikaelnousiainen@xxxxxxxxxxxx>: > > > I've got a very weird issue with PulseAudio when trying to route audio > > from one application (Firefox 64.0b7 (64-bit)) to another one (WSJT-X v1.9.1). > > I'm experiencing the same issue with different browsers (Chrome and Chromium too). > > The browser is receiving audio from a radio transceiver through a WebRTC > > connection and I'm feeding it to WSJT-X to decode the data in the audio signal. > > > > I'm using two module-null-sink modules to transfer the audio between > > the browser and WSJT-X. I use pavucontrol to make the browser play audio to > > null sink called "radio-output" and then let WSJT-X listen to the audio > > via "radio-output.monitor". The kind of setup exists for transmitted audio > > where WSJT-X feeds audio to the browser through a null sink called "radio-input". > > > > However, the issue her is that WSJT-X is mostly not able to decode the data > > when it's using "radio-output.monitor" as audio input. Sometimes it works > > and sometimes it does not. As a technical detail, I'm trying to decode FT8 > > digital mode traffic and I've confirmed that the reason is not related to > > bad time sync (which FT8 requires), because I can even play the browser > > audio through laptop speakers and let WSJT-X use the laptop microphone as > > audio input and it decodes the data just fine -- the audio sounds clean > > and strong with no audible artifacts. > > We need to figure out whether this is due to a monitor or due to a > null sink. Could you please let the browser play to your speakers, and > WSJT-X record from the monitor of the sound card that the browser is > playing to? Does it work? > > Is the webrtc feed public? I.e., can I run WSJT-X locally in order to > reproduce the issue? The problem is most likely due to this bug regarding monitor sources: https://gitlab.freedesktop.org/pulseaudio/pulseaudio/issues/304 Whenever the monitored sink has a rewind, a chunk of audio is apparently duplicated in the monitor source. It would be great if someone could figure out what goes wrong in the monitor rewinding code. -- Tanu https://www.patreon.com/tanuk https://liberapay.com/tanuk _______________________________________________ pulseaudio-discuss mailing list pulseaudio-discuss@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss
