[FFmpeg-user] G711 streaming

[SCHILL Rolf]

Hello (ffmpeg) world

I try to stream a wav file to an old fashioned voip device. It provides no rtcp or rstp support. It needs the packet with g711 codec content  in 20 ms  timing.

I try it with

ffmpeg -I nput.wav -re -acodec pcm_alaw -f rtp rtp://ip-addr:portnumber?pkt_size=172


This command streams well but all packets are send out in more or less a half second until the next packets come.

So the bitrate per second is ok, but not the timing.
See an csv export from the wireshark rtp tools

21,"356","370554515","0.01","13.58","374.73","31.92","","[ Ok ]","12/18/2012 17:08:52.517","204"

22,"357","370554665","0.01","13.91","393.47","33.44","","[ Ok ]","12/18/2012 17:08:52.517","204"

23,"358","370554815","0.01","14.21","412.21","34.96","","[ Ok ]","12/18/2012 17:08:52.517","204"

24,"359","370554965","0.01","14.49","430.95","36.48","","[ Ok ]","12/18/2012 17:08:52.517","204"

25,"360","370555115","0.01","14.76","449.69","38.00","","[ Ok ]","12/18/2012 17:08:52.517","204"

26,"361","370555265","0.02","15.00","468.42","39.52","","[ Ok ]","12/18/2012 17:08:52.517","204"

27,"362","370555415","0.01","15.24","487.15","41.04","","[ Ok ]","12/18/2012 17:08:52.517","204"

28,"363","370555565","0.02","15.46","505.89","41.73","","[ Ok ]","12/18/2012 17:08:52.517","100"

35,"364","370555611","511.57","46.10","0.07","43.25","","[ Ok ]","12/18/2012 17:08:53.028","204"

36,"365","370555761","0.02","44.39","18.80","44.77","","[ Ok ]","12/18/2012 17:08:53.028","204"

37,"366","370555911","0.00","42.79","37.54","46.29","","[ Ok ]","12/18/2012 17:08:53.028","204"

38,"367","370556061","0.00","41.29","56.29","47.81","","[ Ok ]","12/18/2012 17:08:53.028","204"


Does anyone has an idea how to solve the problem?

My google search and searching the doc gives me no answer, maybe I am to stupid or only a few people try to do such things ....

Mit freundlichen Grüssen, With best regards

Rolf Schill

------------------------------------------------------------------------------------