I have many wav files I need to process and save as mono 8khz ulaw. The source files are CD quality (44.1khz stereo 16bit PCM) wav files.
I have created a chain to normalize, convert to mono, and export as wav. The normalize and convert to mono parts work great, but the export wav always creates 44.1khz mono 16bit PCM wav files. I cannot figure out how to get ExportWav to resample and save as ulaw wav files. Is this possible? I’ve searched the forum and found one reference to an unreleased build that has this feature. Please help.
I can do this manually by setting the project rate to 8khz, choosing File, Export, Other uncompressed files, options, and set Header to WAV and Encoding to U-Law.
Chains can’t export to “Other uncompressed files”. It’s a feature request.
I made the unreleased build mentioned in the Forum topic, but that build is very old now (it dates from Audacity 1.3.14-alpha).
Someone did subsequently provide a patch for a better solution, but the last version of it had flaws when I built it that meant that some effects did not work. I’ve asked the author of that patch if he has the time to resume work on export parameters for Chains, but until then the old 1.3.14-alpha build is all there is.
Note that if you don’t have too many files to process you can File > Import > Audio… the files to be converted then use Export Multiple, which will use the current setting for “Other uncompressed files”.
If all you are doing is converting files, a command-line utility (or conversion utility such as dBPowerAmp) will be much quicker than using Audacity because you don’t have to wait for the waveform to load.