Make all audio constant bitrate

[brollin]

Important learning: we cannot use variable bit rate mp3. Wavesurfer and HTML5 audio have issues with desynchronizing the audio and the waveform.

I was using youtube-dl/ffmpeg and downloading almost all of the audio as variable bitrate. We need to run a script to update all of the audio files in S3, ideally in-place. We want to use a constant bitrate, e.g. 256 Kbps.

Helpful commands:

youtube-dl -f bestaudio --extract-audio --audio-format mp3 --audio-quality 256K 'https://www.youtube.com/watch?v=...'
ffmpeg -i The\ Blue\ Whale-yjamrOtMKfE.webm -q:a 256K -map a the-blue-whale.mp3

• bent-kiasmos.mp3
• cloudkicker-explorebecurious.mp3
• concerning-hobbits.mp3
• Crossing Mars.mp4
• Dimond Saints Howler.mp3
• looped-kiasmos.mp3
• Ott. - Skylon - 02 The Queen Of All Everything.mp3
• ratatat-tacobelcanon.mp3
• the-blue-whale.mp3
• the-king-beetle-on-a-coconut-estate.mp3
• Theophany - Time's End II- Majora's Mask Remixed - 05 Woods of Mystery.mp3
• to-live-is-to-die-pulling-teeth.mp3
• together-syence-nicole-kidman.mp3
• no-skin.mp3
• so-down.mp3

[brollin]

Per Kevin's idea in the PRD, we can use a lambda to do this on upload.