..G722 - Raw CCITT/ITU G.722 6/7/8-bit ADPCM format data
.G722-6 - Raw CCITT/ITU G.722 6-bit (48-kbps) ADPCM format data
.G722-7 - Raw CCITT/ITU G.722 7-bit (56-kbps) ADPCM format data
.G722-8 - Raw CCITT/ITU G.722 8-bit (64 kbps) ADPCM format data
There's no standard file extension for this data type and there's no way to auto-detect it. You need to use one of the following file extensions to tell the program what format it is:
Data can also be stored in either 'little endian' or 'big endian' bit-streams.
If you don't know which of them you want, you'll have to experiment.
- Use a file extension of .G722-6 for 6 bits/codeword (48 kbps at 16000 Hz).
- Use a file extension of .G722-7 for 7 bits/codeword (56 kbps at 16000 Hz).
- Use a file extension of .G722-8 for 8 bits/codeword (64 kbps at 16000 Hz).
- An extension of .G722 is assumed to be 8 bits/codeword - this may be wrong though, so it's better if you use one of the above.
In Awave Audio, you select the endian-ness in the
Format options... dialog (button on the Select output options page).
Note that G.722 encodes two samples for every codeword, i.e. 6/7/8 bit codewords corresponds in mean to 3/3½/4 bits/sample, though in actual fact each codeword consists of 2 bits encoding an upper freqency band, and 4/5/6 bits encoding a lower frequency band.
- Dual band ADPCM 6 / 7 / 8-bit lossy compression, mono.