mp3: only layer3 (want 1; got 3) is supported!

[wallnutkraken]

Steps to reproduce:

1. Open this file: http://www.podtrac.com/pts/redirect.mp3/traffic.libsyn.com/cortex/Cortex_053.mp3
2. call Decode() on the file

Expected result: The file is decoded successfully.

Actual result: The function returns an error saying mp3: only layer3 (want 1; got 3) is supported!

Notes: Some other files work perfectly fine, for example: http://www.podtrac.com/pts/redirect.mp3/traffic.libsyn.com/cortex/Cortex_007.mp3

[hajimehoshi]

Thanks, reproduced.

[hajimehoshi]

@alistanis Do you have any suggestion? I feel like go-mp3 should consider tags.

[hajimehoshi]

Fixed.