Technical discussions related to Speech Coding (all itu and other vocoders, ACELP, CELP, AMR, etc)
Hi,
I have cross compiled the AMR-WB+ C reference code distributed as part of the 3gpp spec and
it is able to decode the AMR-WB+ test files. Now my question is,
1.Will this decoder decode AMR-WB files?(.awb files/.if2 or the .cod files that come with the
test suite spec for AMR-WB).
2.What does it take to make this decoder decode those AMR-WB files(.awb etc)? Will just
tampering the headers help? Is the speech coded bit ordering compatible?
It would be really helpful if anybody can throw some light on this?
Thanks,
Regards,
mr_79
Hi Mohan, The AMR-WB files can have two formats, IF2 or RFC 3267(default). The RFC is the common file format for the .awb file. The IF2 is compatible with cell network interface (as far as I know). The .cod files are not use other than for the test sequence files. Every bit is written as a word. The AMR-WB+ decoder can decode AMR-WB formatted as per the AMR-WB+. The encoded bit ordering is compatible, you have to swap the AMR-WB header (1 byte) with an AMR-WB+ header (2 bytes) and remove the magic number at the beginning of the .awb file. You can find the details on the header in the documents: link from our web: http://www.voiceage.com/relatedstandards.php - RFC 3267 "Real-Time Transport Protocol(RTP) Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs", sections 5.1 and 5.3. - RFC 4352 "Real-Time Transport Protocol (RTP) Payload Format for the Extended Adaptive Multi-Rate Wideband (AMR-WB+) Audio Codec - TS 26.412 <http://www.3gpp.org/ftp/Specs/html-info/26412.htm> General audio codec audio processing functions; Source code for 3GP file format Best regards, ----------------------- Claude Gravel VoiceAge Corporation http://www.voiceage.com <http://www.voiceage.com/> ________________________________ From: s...@yahoogroups.com [mailto:s...@yahoogroups.com] On Behalf Of m...@rediffmail.com Sent: Monday, December 03, 2007 5:43 AM To: s...@yahoogroups.com Subject: [speechcoding] AMR-WB+ decoder with AMR-WB files Hi, I have cross compiled the AMR-WB+ C reference code distributed as part of the 3gpp spec and it is able to decode the AMR-WB+ test files. Now my question is, 1.Will this decoder decode AMR-WB files?(.awb files/.if2 or the .cod files that come with the test suite spec for AMR-WB). 2.What does it take to make this decoder decode those AMR-WB files(.awb etc)? Will just tampering the headers help? Is the speech coded bit ordering compatible? It would be really helpful if anybody can throw some light on this? Thanks, Regards, mr_79