calling vorbis_info_clear() before vorbis_dsp_clear() causes memory leak
this is a suggestion to include a warning in the documentation.
vorbis_info_clear() clears vi->channels, so that a subsequent call to vorbis_dsp_clear() fails to free v->pcm[i] for each channel.
i ran into this problem because i called these functions in the wrong order. that was careless of me, of course, because info is initialized before dsp, and i should have clear'ed them in the reverse order. still, this is a difficult bug to track down because an ordering mismatch like this usually causes a crash, but in this case, it causes a leak.
a warning note along the lines of
"not clearing data structures in the reverse order in which they are allocated will likely result in a memory leak".