Audacity Forum

Hello,

I have an application that requires certain types of audio files as input. It's quite strict and I'm having a hard time figuring out how to do this. The files it accepts are:

.wav format (RIFF header), sampling rate of 8kHz or 16kHz, mono, 16 or 8 bit linear
OR...
headerless (raw format), sampling rate of 8kHz, mono, 8-bit Mulaw

I don't really understand what RIFF header are or Mulaw. I really just need to know if audacity can create these files and if so, how. If it can't, can you recommend any other apps that might be able to?

thanks!

The standard WAV export file from Audacity includes the RIFF header.

To set the sampling rate of the exported file, set the "Project Rate (Hz)" menu at the bottom left of the Audacity project window.
http://manual.audacityteam.org/man/Selection_Toolbar

To produce a mono file your project must not include any stereo tracks.

After you do File > Export, make one of these selections in the "Save As Type" dropdown menu in the "Export File" dialog box
http://manual.audacityteam.org/man/File_Export_Dialog

• "WAV (Microsoft) signed 16-bit PCM" (this is the easiest choice and will produce the mono 16 bit linear file)
or
• "Other uncompressed files" (use this option to produce the mono 8 bit linear file)
If you choose the latter, click the "Options" button and then in the "Specify Uncompressed Options" dialog, set the "Header" dropdown menu to "WAV (Microsoft)" and the "Encoding" dropdown to "Unsigned 8-bit PCM"

Producing the headerless raw files would, I think, be a case of trial and error, and I'm not sure if Audacity can do it, even with "Custom FFmpeg Export".

-- Bill

billw58 wrote:Producing the headerless raw files would, I think, be a case of trial and error, and I'm not sure if Audacity can do it, even with "Custom FFmpeg Export".

You can do that by selecting "Other uncompressed files > RAW > uLaw", however I'd recommend trying the "WAV (Microsoft) signed 16-bit PCM" option first as that is by far the least problematic.