[itu-sg16] Question on G.726

Dear Q10/16 Experts,

Sorry to bother you.

We have found unexpected results when using G.726. When particular waveform audio data are input to G.726 encoder, the decoded data from G.726 decoder include large amplitude impulses. We can reproduce the same phenomena at any of 16, 24, 32 or 40kbps bitrate when we put sine wave signal with very low frequency such as 1Hz or 2Hz into G.726 codec.

Our codec module is generated from the C source code provided by G.191 software tools as is and the all test sequences provided by G.726 Appendix II are passed with this module.

It would be appreciated if anyone could give me some suggestions regarding this matter.

Thanks and best regards,

Tetsuya Yamamoto Sony Corporation