[Speex-dev] IAX2 speex payload using ZoIPer

[Jim Crichton]

I have not used IAX, but do you have any reason to believe that this extra data is meaningful?  It looks rather like a bug (or configuration problem), where the frame size is set as if it were a G.711 frame, while the Speex data takes only the first 20 bytes (Mode 3, as you said).  You could try ignoring it, but 140 trash bytes is a lot of wasted bandwidth.

This looks like an application problem, so this list is probably not the best place to find an answer.

- Jim

  ----- Original Message ----- 
  From: Van Rensburg, Hendrik 
  To: speex-dev at xiph.org 
  Sent: Tuesday, April 08, 2008 4:08 AM
  Subject: [Speex-dev] IAX2 speex payload using ZoIPer


  Using Wireshark I can see that ZoIPer always send a 160 byte payload.  First few payloads contain 20 bytes of data (what I believe to be a mode 3 frame, ie first byte in 0x18 - 0x1F range), followed by 0x7B (21st byte), ie. 5 bit 0x0F terminator padded with 011. . and then zeroes all the way up to 160 bytes.

   

  . but then after a few payloads there are more following these 21 bytes . typically looking like this:

   

  0000  00 0c 29 02 83 c6 00 1c  25 10 d0 48 08 00 45 00   ..)..... %..H..E.

  0010  00 c0 4c 58 00 00 80 11  53 38 0a cb 42 82 0a cb   ..LX.... S8..B...

  0020  42 85 11 d9 11 d9 00 ac  6d d2 00 04 0c 80 >> Payload starts here >> 1d be   B....... m.......

  0030  24 9c 1c 59 38 59 74 90  48 be 91 e6 8b c9 ef 99   $..Y8Yt. H.......

  0040  68 ee >> Terminatar as 21st byte >> 7b >> and then . >> 1a 24 03 50 00  00 00 1c 1a 24 03 03 00   h.{.$.P. ....$...

  0050  00 00 0f df 80 41 4e 8b  17 c0 10 3f 45 c1 78 55   .....AN. ...?E.xU

  0060  a7 c0 9f 89 94 c0 5c 06  b4 c0 12 ac c8 c0 88 23   ......\. .......#

  0070  21 41 50 69 2e c1 0c 8a  13 c1 ba 24 7b c0 c3 55   !APi.... ...${..U

  0080  a3 c0 c6 51 d6 c0 94 94  49 c0 af 0e 77 41 dd aa   ...Q.... I...wA..

  0090  fe c0 40 e4 2e c1 00 00  00 00 60 d4 23 03 40 1c   .. at ..... ..`.#. at .

  00a0  59 3e e8 d7 23 03 fc ef  a6 03 00 00 00 00 a0 00   Y>..#... ........

  00b0  00 00 00 00 80 3f 34 a2  f4 bf 21 3c 6a 3f 00 00   .....?4. ..!<j?..

  00c0  80 3f 5e a2 f6 bf 03 43  6e 3f 00 00 80 3f         .?^....C n?...?  

   

  Questions:

   

    1.. What is the rest and how do I decode it with my own VoIP client? 
    2.. How do I encode my outgoing audio so that it looks something like the above? 
   

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