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AMR-WB+ decoder with AMR-WB files

Started by moha...@rediffmail.com December 4, 2007
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 General
audio codec audio processing functions; Source code for 3GP file format

Best regards,

-----------------------
Claude Gravel
VoiceAge Corporation
http://www.voiceage.com

________________________________

From: s... [mailto:s...]
On Behalf Of m...@rediffmail.com
Sent: Monday, December 03, 2007 5:43 AM
To: s...
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