Did you check with the latest QM 1.4.0? we did a bit of work on content type and file name in 1.4.0, so it should be correct by now.
Anyway, generally speaking, I usually see two different scenarios for bulk recording real-life calls:
- WAV49. If you run Windows clients, WAV49 will create WAV files that are actually GSM files but can be played natively on Windows systems. They look like standard PCM WAV files, but are actually compressed. This is very easy and effective.
- WAV + MP3. You record all files as WAV, but you run a nightly process to encode them into MP3. This means that you will use CPU cycles to perform the compression at night and save a lot of space on older files, while today's recordings are plain WAV.
You can use something like:
for i in *.wav; do lame --preset phone $i `basename $i .wav`.mp3; rm -f $i; done
to get the work done at night through a cron job.