topic Re: Using GSM-FR decode/endocde with MS WAV 65 byte double fram in Intel® Integrated Performance Primitives

Using GSM-FR decode/endocde with MS WAV 65 byte double frames

fviggian — Thu, 26 Mar 2009 17:41:45 GMT

I'm using the USC library with IPP 5.2, implementing code to decode a WAV file GSM-FR codec file to PCM-16, and also to encode PCM-16 to GSM-FR and store in an MS WAV file. The Decode function works if passed 33 byte GSM-FR packed frames, but will not handle the 65 byte packed double frames which MS uses. Similar problem when encoding -- I tried simply packing together the two 32.5 byte encoded frames into a 65 byte frame, but it is not that simple. Does anyone have experience using the library with the MS 65 byte format?
Thanksin advance,
Frank

Re: Using GSM-FR decode/endocde with MS WAV 65 byte double fram

Vladimir_Dudnik — Thu, 26 Mar 2009 17:45:54 GMT

Do you have a chance to check this with the latest IPP 6.0 release?

Vladimir

Re: Using GSM-FR decode/endocde with MS WAV 65 byte double fram

fviggian — Fri, 27 Mar 2009 18:34:53 GMT

Quoting - Vladimir Dudnik (Intel)

Do you have a chance to check this with the latest IPP 6.0 release?

Vladimir

No, we don't have IPP 6.0 here. Do you know if GSM-FR support for MS WAV format has been added in the 6.0 release?

Re: Using GSM-FR decode/endocde with MS WAV 65 byte double fram

Vyacheslav_Baranniko — Mon, 06 Apr 2009 08:58:59 GMT

Quoting - fviggian

Hi Frank

IPP does not support Microsoft propriatary GSMWAVformat (MSGSM), instead IPP support GSM RTP format (see RFC3551).Each frame in RTPGSM format has 4 leadingextra bits which are not used for decompression, so can be be omitted.These bits must beremoved by left-shift of all bits while packing two RTP GSM frames intoMSGSM 65-bytes double frame and vice versa.

Best regards, Vyacheslav, IPP, speech codecs.