topic Problem with umc_speech_rtp_codec in Intel® Integrated Performance Primitives

Problem with umc_speech_rtp_codec

roccap — Thu, 23 Sep 2010 12:03:03 GMT

Hi,
I have downloaded and built the IPP samples and I'm trying to use
the sample umc_speech_rtp_codec app to convert some rtpdump
files to wavs. I use the command line.

umc_speech_rtp_codec -format IPP_G711 test test.wav

This works happily for G711 files, but G729 coded produce a very
short wav of silence. The IPP codecs themselve appear to work as
I can transcode wavs happily using the other sample app.
Any suggestions?

A second question, why do I need to tell it the payload type 'cos this
is in the rtp header (assuming not dynamic)?

TIA

Paul

Problem with umc_speech_rtp_codec

Igor_B_Intel1 — Thu, 30 Sep 2010 05:17:32 GMT

Hi Paul,
A lot of information about speech codecand its parametersare missed in RTP header because it provided through SDP protocol during session initiation and doesn't stored in rtpdump file. More over not all G729 annexes (just baseline) got assigned static payload type so additional information for umc_speech_rtp_codec should be provided through cmd args. Wrong decompression could occure when wrond cmd params are passed because this is resulted in not corresponding depacketizer choosing.

Igor S. Belyakov