MP3_MASK           60 libavcodec/mp3_header_decompress_bsf.c     header= AV_RB32(ctx->par_in->extradata+11) & MP3_MASK;
MP3_MASK          100 libavformat/mp3dec.c                 header_emu += (next_sync & MP3_MASK) == (header & MP3_MASK);
MP3_MASK          413 libavformat/mp3dec.c                 (header & MP3_MASK) == (header2 & MP3_MASK))