CCITT A-Law 8 bits / 8KHz ... and U-Law

Please, can you add the possiblity to export in these 2 audio formats : CCITT A-Law 8 bits / 8KHz … and CCITT U-Law … without any tag.
I don’t want to export in a format to reexport later with wavelab or Soundforge (batch) cause it’s toooo long … and on post-prod, we never has enough time … so, this feature would be a great add.

Other features requested : double or triple export in the same time, but with different audio format. (ex : .wav PCM mono 16 bits / 48Khz + .wav CCITT A-Law 8 bits / 8Khz mono).





Yes this is useful for voice over IP answering machines projects. It’s strange that Nuendo does not do that. More it’s a compression function available natively inside Windows (i don’t know for MACs).

In the meantime you could use Wavelab watch folder to do that automatically.

Or use another less expensive batch converter software that can do this. Seems that a couple ones are doing this. Google it : “audio converter watch folder”.

Or simply use a Task Automation software, Robotask for example, that can watch for file creation inside a folder and run a command on it, for example start the free command line audio file converter SOX and delete the original file after compression. SOX is frequently used for conversion to uLaw and ALaw. It is the Swiss Army knife of sound conversion / processing programs. I was using that when i was working in the VOIP market. Free and good quality.

Another possibility would be the Watch 4 Folder software (free version for a single monitored folder). Using probably a change folder event, not file creation.

Export to 16 bits 48 KHz .wav from Nuendo and do the final conversion with Sox.

sox -V vm-intro.wav -r 8000 -c 1 -t ul vm-intro.ulaw
sox -V vm-intro.wav -r 8000 -c 1 -t al vm-intro.alaw

I’ve read that Wavelab use Sox internally for re-sampling.

Instead of Sox, you could use FFMPEG that will give the possibility to convert to multiple file formats at the same time on the same command line :

ffmpeg -i input.wav output.ogg output.mp3 output.flac

And on linux there is the possibility to make things more parallel to better use multi core processors using “parallel” command :

parallel ffmpeg -i {1} {1.}.{2} ::: *.wav ::: ogg mp3 flac

{1} = replacement string for first input source
{1.} = replacement string for first input source with extension removed
{2} = replacement string for second input source
::: *.wav = input source 1
::: ogg mp3 flac = input source 2

Hopefully the telephony market is now (slowly) switching to something better than the (legacy we could say !!) 8 KHz ALaw / ulaw now, thanks to smartphones and VOIP phones with better codecs !

So do no forget to keep your 16 bits 48 KHz original files, as one day or another perhaps you’ll need them for a client.

After looking around a simple and efficient solution is probably to use FFmpeg Batch (and it’s free).

FFmpeg Batch is a GUI for FFmpeg.

There are 32 and 64 bits packages, portable or not.

Do allow encoding with multiple output file formats at the same time, and can process multiple input files at the same time to better use multi core processors.

Use something like this for wav to mulaw :

ffmpeg -i input.wav -af "highpass=f=300, lowpass=f=3400" -ar 8000 -ac 1 -ab 64k -f mulaw output.ulaw

The only missing feature is watch folder (hot folder).

If you need this feature then it’s better to use a watch folder utility (Robotask, Watch 4 Folder…), in tandem with FFmpeg command line.