Hi Siga, the best way to test your audio code is to use the same code in a simple program. Write a program that reads 8000Hz 16bit single channel PCM from a file which then compresses it and then decompress it to an output file. Then playback your new output file, if it's corrupted you have a problem in your code. However, if it's not corrupted, then take a look at how your RTP code is feeding the payload into the decoder. Another step would be to verify that the audio being sent to you is what you're expecting. Wireshark has built in support to play G.711 RTP streams, so give that a try. If Wireshark plays back noise then you know it's not your problem.
Brandon On 04/01/2011 08:15 AM, Siga wrote: > Hi, > when I try to feed the RTP Payload with passing through the decoder > (as mentioned by Brandon), the output is only noise. On the other hand > after passing it through the decoder I could at least hear some audio > but with noise. Can anybody give some valuable suggestions on this. > > Regards > > On Tue, Mar 29, 2011 at 9:00 PM, Brandon W. Yuille <[email protected] > <mailto:[email protected]>> wrote: > > Hi Siga, > > Isn't G.711 decoded already signed 16bits per sample @ 8000Hz PCM (I > seem to remember that's what the ITU implementation outputs - signed > short array)? I don't believe you need to do any resampling if your > playback device is setup to use 16bit single channel 8000Hz PCM audio. > > Brandon > > On 03/29/2011 10:46 AM, Siga wrote: > > Hi, > > I need some assistance from the SIP professionals regarding the > decoder > > part, i am using A-Law for encoding and decoding. My encoder for > RTP > > packets using G.711 A-law encoder works pretty much OK, but I > have got some > > flaws with the decoding part. Especially with the upsampling > conversion from > > 8 bits to 16 bits, what should be the size of the buffer for > storing the > > decoded RTP payload. I can hear some audio but with poor quality. > > > > Any working example regarding this part would be helpful for my > analysis. > > > > Regards > > _______________________________________________ > > Sip-implementors mailing list > > [email protected] > <mailto:[email protected]> > > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > > _______________________________________________ > Sip-implementors mailing list > [email protected] > <mailto:[email protected]> > https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors > > _______________________________________________ Sip-implementors mailing list [email protected] https://lists.cs.columbia.edu/cucslists/listinfo/sip-implementors
