Several questions regarding the Python bindings for GStreamer (Asyncio compat, mixing of streams, reading directly from BytesIO)

[Hadrien Titeux]

Hello,

It's kind of my first time posting on a dev mailing list so please, be 
gentle. If the questions that follow are totally out of place, I'm 
really sorry for wasting your time (but could you please redirect me to 
some place where people my answer might answer my questions)

My question stems from a a particular small usecase of Gstreamer. The 
problematic is the following: I want to build a client for some sort of 
audio chat (it's a bit uncommon, don't ask) that sends wav audio bytes 
over websocket. I've already built most of the interface using the 
GTK3+ bindings for Python, and now the sound-playing part remains. I 
could very well use the portaudio bindings (and i've done it on another 
terminal-based client) to do this, but I'm in a mood where I want to 
tackle this problem using the gst python bindings (because portaudio 
kind of sucks).

So, here are what I'd like to know:
- Is it possible to play a .wav file without saving it to disk first? 
Like, directly from the byte file stored in the python memory (as 
portaudio can do it)
- The websocket receives sounds asynchronously with the asyncio module. 
I've seen that Gbulb permits the use of the Gtk event loop with 
asyncio. I'll be thus receiving sound bites that i'll have to play 
right at the moment I receive them through my websocket client, 
sometimes overlapping each other when they're being played. This 
requires asynchronously mixing several audio files. Do you think this 
is feasible with the gst bindings?

To give you an idea of what i'd expect, here's the portaudio 
implementation of what I need: 
https://github.com/loult-elte-fwere/termiloult/blob/master/tools/audiosink.py

I can't find any documentation on this kind of usage of gstreamer, 
apart from the cold  PyGObject API reference.

Thanks in advance for your help,
Hadrien
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/gstreamer-devel/attachments/20180824/aafebc1a/attachment.html>