Howto:Convert wave files in to G722 coder files

Applies To

This information applies to

• All innovaphone gateways (IP302, IP305, IP800, IP30x0, IP60x0) Version 9 and later.

More Information

Problem Details

As mentioned in the related article, softcod is used for conversion of WAV files to G711/G723/G729 formatted files.

When aiming for the new G722 and G722.2 (AMR-N/AMR-WB) codecs, softcod does not fit.

Therefore, another commandline tool called ffmpeg can be used.

At the ffmpeg-builds site you will find different variants for your appropriate Windows OS version (tests have been done with "static" build).

Usage

After successful download and installation, the following commands can be used to convert any wav-files:

• Step to the directory where you've installed ffmpeg, step down to the subdirectory bin.

• The command line format is:

ffmpeg -i <inputfile>.wav -ar <sampling rate> -ab <bitrate> -acodec <codec> <outputfile>

• Explanation:
  • <inputfile>  : location and filename of the standard wave file
  • <sampling rate>  : set the audio sampling frequency. For output streams it is set by default to the frequency of the corresponding input stream. Possible values would be 8000 / 16000
  • <codec>  : "g722" for G722, "libopencore_amrnb" for G722.2 AMR-NB, "libvo_amrwbenc" for G722.2 AMR-WB
  • <bitrate>  : set bitrate (in bits/s) depending on the used G722.2-codec
    • for G722.2 AMR-NB : 4.75k, 5.15k, 5.90k, 6.70k, 7.40k, 7.95k, 10.20k, 12.20k (default)
    • for G722.2 AMR-WB : 6.60k, 8.85k, 12.65k, 14.25k, 15.85k, 18.25k, 19.85k, 23.05k, 23.85k (default)
  • <outputfile>  : name and optional location of the resultfile

Examples

Conversion of a wav-sample into a g722-coded audio file

ffmpeg -i /tmp/sample.wav -ar 8000 -acodec g722 /tmp/sample.g722

Conversion of a wav-sample into a g722.2 AMR-NB-coded audio file

ffmpeg -i /tmp/sample.wav -ar 8000 -ab 5.90k -acodec libopencore_amrnb /tmp/samplenb.amr

Conversion of a wav-sample into a g722-coded audio file

ffmpeg -i /tmp/sample.wav -ar 16000 -ab 19.85k -acodec libvo_amrwbenc /tmp/samplewb.amr

Related Information

ffmpeg supported audio codecs

Howto:Installing_the_voicemail/music_on_hold_on_a_compact_flash_card

Howto:General_information_for_compact_flash_cards

Howto:Convert wave files to G7xxx with softcode

File format