How to convert .sd2 audio to .mp4 format.
It appears that converting Sound Designer II Format directly to MPEG-4 Videos (.sd2 to .mp4 conversion) is not possible, at least not with a small workaround.
First, use one of several (online) file conversion tools, such as Apple Logic Pro, which should be capable of converting SD2 to WAV. You can then easily convert WAV to MP4.
A digital audio workstation and MIDI sequencer program
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