ff_imdct15_init  1158 libavcodec/aacdec.c     ret = ff_imdct15_init(&ac->mdct480, 5);
ff_imdct15_init    47 libavcodec/imdct15.h int ff_imdct15_init(IMDCT15Context **s, int N);
ff_imdct15_init  2207 libavcodec/opus_celt.c         ret = ff_imdct15_init(&s->imdct[i], i + 3);