I’ve spent a couple days looking into this and most comments on various sites seem to say it’s not possible.
We have numerous systems that use Dialogic vox files that are 4-bit 6kHz files. Unfortunately, Asterisk seems to only play 4-bit 8kHz files.
Has anyone been able to successfully play and record 4-bit 6kHz .vox files with asterisk, or would anyone have some good ideas of what would be required to make this change?
I was thinking it would require either altering the ADPCM codec or the VOX format sources. (Was thinking altering the latter by reading every 3 bytes and returning 4 bytes in its place in the frame.)
Any ideas or suggestions are welcome.