Allow storing audio files in FLAC when harvesting.

[atruskie]

There will be a requirement to store source audio data in FLAC as we scale data collection.

Add the option to the harvester to encode processed data into the FLAC format.

Ensure original audio metadata is kept.

Read https://xiph.org/flac/faq.html#general__no_wave_metadata

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new notes

• can we store:
  • FLAC as FLAC?
  • WAV as FLAC
  • (if harvested wac files keep wav file as original, closes #35 #49 lands) store WAac as FLAC?
  • MP3 as FLAC?
• Is there any option to enable these choices?
• On which file is the HASH calculated? The source file or the FLAC result?
  • Perhaps it should be for both! Store the original file SHA-256 in the audio notes field
• Is the FLAC encoding/decoding deterministic (it needs to be)?

The goal with #36 is to transcode all new audio into FLAC since storing WAV is untenable.

[cofiem]

Ha, finally this is actually a requirement. This is for cached files, not originals?

[atruskie]

This will be for original audio files.