G726 playback in specific time always start from file beginning

I am using ARI (asterisk 13) to playback long files (over an hour of speech). I am using dtmf’s to allow the user to skip forward or backwards, by stopping the playback, and restarting it in a different time point. This works with ulaw, wav or vox formats, but with g726 (g726-32) it doesn’t. Instead of restarting at the time point I set it to, it always start from the beginning of the file.
Any idea what happens here or how to solve it?

Eyal Hasson.

My guess would be because you cannot just start playing out ADPCM at an arbitrary point in time because the coding depends on what has gone before, and could, potentially, depend on all that has gone before.

Well although sound logical, vox is also an ADPCM format, and does not suffer from this problem.

I can’t find a technical specification for that format, but my guess would be either there are resynchronisation points in the data stream, or the author of the format module chose to accept a transient whilst the decoder refinds the zero level.

Yes, probably. Any suggestion of another good 32k codec for asterisk, which is also supported by ffmeg?