The pointer fp after the call to chromaprint_get_raw_fingerpoint() points to an array
of uint32_t whereas the current code assumed just a char stream. Thus when writing the
raw fingerprint, the output would be truncated by a factor of 4.
For reference the declaration of the function from chromaprint.h is:
int chromaprint_get_raw_fingerprint(ChromaprintContext *ctx, uint32_t **fingerprint, int *size);
It's completely absurd that libavcodec would care about libavformat
locking, but it was there because the lock manager was in libavcodec.
This is more stright forward. Changes ABI, but we don't require ABI
compatibility currently.