Hector Martin

The Joysound Karaoke app for the Switch pulls in music from unencrypted HTTP CDN... and this file format is a perfect example of the kind of failure sadly common in Japanese software development.

So the file format has 3 audio tracks (AAC VBR). What do you do with multiple audio tracks? You multiplex them, of course. The idea is to be able to read the file linearly and play back all three tracks as you go.

Of course, there are already a zillion container formats available that will do this for you. But Japanese developers love to reinvent the wheel, so they did. Unfortunately, someone clearly knew *about* multiplexing but didn't *understand* it.

I'm guessing someone was told to write some multiplexing tool. Unfortunately, the tool multiplexed the files in identically sized blocks. The files have a variable bitrate. this makes the multiplexing pointless, because the data is not synchronized *in time*.