How to register in Liquidsoap the logic of the input.ffmpeg module for receiving rtp stream?

[pavelzabavin]

Question: How to register in Liquidsoap the logic of the input.ffmpeg module for receiving rtp stream?

 # ______ TRANSFER PART to linux /test/
 # working version:
 /usr/local/bin/ffmpeg -loglevel warning -hide_banner -re -i /home/check/behindthewheel.wav -c:a libfdk_aac -b:a 192k -ar 48000 -filter:a volume=8dB -vn -rtpflags latm  -f rtp -payload_type 96 rtp://192.168.10.99:10024

 SDP:
 v=0
 o=- 0 0 IN IP4 127.0.0.1
 s=Behind the Wheel (DJ Matt Hite Mashup)
 c=IN IP4 192.168.10.99
 t=0 0
 a=tool:libavformat 58.29.100
 m=audio 10024 RTP/AVP 96
 b=AS:192
 a=rtpmap:96 MP4A-LATM/48000/2
 a=fmtp:96 profile-level-id=41;cpresent=0;config=400023203fc0

 # ______ RECEPTION PART on FFMPEG /test/

 #working version on Linux:
 ffmpeg -listen_timeout 3000 -protocol_whitelist file,rtp,udp,crypto,data \
 -reorder_queue_size 0 -i /ff/ff_to_ff_rtp_aac.sdp -af aresample=async=1 -f alsa hw:0

 #not working at Liquidsoap
 radio_stream_in_ff = input.ffmpeg(max_buffer=0.5, "/usr/local/etc/AIR-SDP/RTX1-FF_AAC.SDP", format="rtp")
 output.dummy(mksafe(radio_stream_in_ff))

Use Liquidsoap 2.2.1+git@74f79bb7

[toots]

Hi and thanks for reporting!

I'm glad you asked I forgot how you're supposed to do this myself for a second.. 😅

In general, everything you can do with the ffmpeg CLI should work with us. Thus, I'm converting this to a discussion. If it turns out this still doesn't work I'll open an issue.

The way to pass arguments to input.ffmpeg decoder is via the in_args, float_args and string_args. Here's an example with ffmpeg logs enabled and increased liquidsoap logs for debugging as well:

log.level.set(4)
settings.ffmpeg.log.verbosity .set("debug")

s = input.ffmpeg(
  string_args=[("protocol_whitelist", "file,rtp,udp,crypto,data")],
  int_args=[("listen_timeout", 3000), ("reorder_queue_size", 0)],
  "/tmp/bla.sdp"
)

output.ao(
  fallible=true, input.ffmpeg("/tmp/bla.sdp",string_args=[("protocol_whitelist", "file,rtp,udp,crypto,dat")]))

This runs here but does not work because I have no access to the SDP stream.

[pavelzabavin]

Dear friend, thank you for answering my question! It works! 😎

I also tried format=sdp, it also works.