Audacity is able to export through external encoders such as LAME and SoX using an option in the Export menu.
An overview of this is described in the manual http://manual.audacityteam.org/man/Exporting_to_an_External_Program
Here’s the examples of Command Line export options from the Audacity manual:
command - "%f"
The “%f” command passes the file name and extension entered in the File Export Dialog as the output file of the external program.
lame -v -b 112 -c -p - "%f"
produces a variable bit rate MP3 of minimum 112 kbps bit rate, with a copyright marker and CRC error checking enabled.
Here’s some examples more examples (not in the manual):
High quality mono MP3 with LAME:
lame -V 0 -a - "%f"
High compression (small file size) mono MP3 with LAME:
lame -V 9 -a - "%f"
sox -t wav - -t ogg "%f"
Export as an Ogg Vorbis file.
sox -t wav - -t wav "%f" echo 0.8 0.3 30 0.4 reverb 60 10 15 100 10 10
Export as a WAV file with a “bathroom” reverberation effect.
Feel free to add your own recipes.
To just use the command on Windows (without giving a path to the encoder), you’ll need to have installed the Lame or FFmpeg binaries in their default location in “Program Files” so as to create a Windows registry setting that Audacity will look for as the location of the encoder.
Here are a couple of examples with FFmpeg.
This exports a file with the codec forced to Nellymoser Asao, so for example you might want to use .flv extension for the format to export to in Audacity’s “Export File” window:
ffmpeg -i - -acodec nellymoser "%f"
This exports a file forcing the file to a 256 kbps mp2, using FFmpeg from an arbitrary location of your choice (ensure the path has quotes around it if it includes spaces as it does here):
"E:FFmpeg for Audacityffmpeg.exe" -i - -acodec mp2 -ab 256000 "%f"
I’d be interested to know if command-line exporting works on Mac. /src/export/ExportCL.cpp suggests the code does not work on Windows or Mac, but I expect it does.
Exporting U-law encoded file using SOX.
This one is from Leland and is useful for producing standard U-Law 18-byte fmt chunk files as required by many telephony applications.
C:...sox -t wav - -e u-law "%f"