update technical metadata

[keunwoochoi]

As title says. Probably it's not valid?

[tae-jun]

👍 In my case, it's only 1.8KB

[mdeff]

Indeed. Looks like the clipping failed. I have:

• fma_full/133/133297.mp3, 4546530 bytes, sha1 d6a6aa0d0a4264e7679aaca3c3cc4c67127143b7
• fma_large/133/133297.mp3, 1752 bytes, sha1 19c8a6a03db7df5768cc0a424344cb2441875cb0

[mdeff]

Found the problem. The metadata, scraped from the FMA API, claims the song is 600 seconds long, while ffmpeg -i 133297.mp3 -f null - tells us it's about 01:53.56. The trim_audio() function in creation.py is clipping 30 seconds in the middle of the song, that is from 285s to 315s for this particular file. But that is out of the song, which is 114s long.

It's not the first time I see an error in the reported song length. The solution is to extract the duration from the file with ffmpeg and update the metadata. I should do that at some point.

[tae-jun]

@mdeff You are the best! 👍

[mdeff]

Haha thanks @tae-jun :)

While at this, we should collect the following technical metadata to be included in tracks.csv:

• Bit rate
• Number of channels
• Sample rate
• Number of samples
• (Duration is then a function of the above two)

I'll probably do that for the final release. If somebody wants​ to help, you're welcome. :)

[chiwanpark]

I just found same error in fma_small/108/108925.mp3.

[mdeff]

Thanks all for reporting. :) I will fix this problem for the v1 release. Don't hesitate to open issues for other problems if you find some.