sipwavsipp

How to encode WAV to play with SIPp

By looking into another SIPp related question I learned that it is now possible to play WAV files using the rtp_stream action.

I've tried several different WAV files with no success. All I get is some noise instead of the expected sound.

In one comment in the mentioned question there is a simple instruction to convert a WAV file to a compatible format but it didn't work as well.

I've also tried to use sox to convert this file with no success.

Can anyone instruct me on how to generate a valid WAV file to be used with SIPp?

This is my recv 200 OK command which includes the play audio action:

<recv response="200" rtd="true">
  <action>
    <exec rtp_stream="sorry_dave.wav,-1" />
  </action>
</recv>
Solution

  • I was looking for different WAV file encodings and found a lot of them on Wikipedia.

    I've found one file (8,000 Hz µ-Law) that works correctly with the rtp_stream="8kulaw.wav,-1,0" exec parameter.

    This is the file information:

    ubuntu@mylinux:~/$ file 8kulaw.wav
8kulaw.wav: RIFF (little-endian) data, WAVE audio, ITU G.711 mu-law, mono 8000 Hz

    I've tried to encode this file to the exact same configuration using this Sox command but it did NOT worked:

    sox -r 8000 -e u-law sorry_dave.wav sorry_dave4.wav