ref: 38ea1ac105f4484f02bba3bfbc790ebe4f18f016
dir: /sys/src/cmd/audio/mp3dec/frame.h/
/* * libmad - MPEG audio decoder library * Copyright (C) 2000-2004 Underbit Technologies, Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * $Id: frame.h,v 1.20 2004/01/23 09:41:32 rob Exp $ */ # ifndef LIBMAD_FRAME_H # define LIBMAD_FRAME_H # include "fixed.h" # include "stream.h" enum mad_layer { MAD_LAYER_I = 1, /* Layer I */ MAD_LAYER_II = 2, /* Layer II */ MAD_LAYER_III = 3 /* Layer III */ }; enum mad_mode { MAD_MODE_SINGLE_CHANNEL = 0, /* single channel */ MAD_MODE_DUAL_CHANNEL = 1, /* dual channel */ MAD_MODE_JOINT_STEREO = 2, /* joint (MS/intensity) stereo */ MAD_MODE_STEREO = 3 /* normal LR stereo */ }; enum mad_emphasis { MAD_EMPHASIS_NONE = 0, /* no emphasis */ MAD_EMPHASIS_50_15_US = 1, /* 50/15 microseconds emphasis */ MAD_EMPHASIS_CCITT_J_17 = 3, /* CCITT J.17 emphasis */ MAD_EMPHASIS_RESERVED = 2 /* unknown emphasis */ }; struct mad_header { enum mad_layer layer; /* audio layer (1, 2, or 3) */ enum mad_mode mode; /* channel mode (see above) */ int mode_extension; /* additional mode info */ enum mad_emphasis emphasis; /* de-emphasis to use (see above) */ unsigned long bitrate; /* stream bitrate (bps) */ unsigned int samplerate; /* sampling frequency (Hz) */ unsigned short crc_check; /* frame CRC accumulator */ unsigned short crc_target; /* final target CRC checksum */ int flags; /* flags (see below) */ int private_bits; /* private bits (see below) */ }; struct mad_frame { struct mad_header header; /* MPEG audio header */ int options; /* decoding options (from stream) */ mad_fixed_t sbsample[2][36][32]; /* synthesis subband filter samples */ mad_fixed_t (*overlap)[2][32][18]; /* Layer III block overlap data */ }; # define MAD_NCHANNELS(header) ((header)->mode ? 2 : 1) # define MAD_NSBSAMPLES(header) \ ((header)->layer == MAD_LAYER_I ? 12 : \ (((header)->layer == MAD_LAYER_III && \ ((header)->flags & MAD_FLAG_LSF_EXT)) ? 18 : 36)) enum { MAD_FLAG_NPRIVATE_III = 0x0007, /* number of Layer III private bits */ MAD_FLAG_INCOMPLETE = 0x0008, /* header but not data is decoded */ MAD_FLAG_PROTECTION = 0x0010, /* frame has CRC protection */ MAD_FLAG_COPYRIGHT = 0x0020, /* frame is copyright */ MAD_FLAG_ORIGINAL = 0x0040, /* frame is original (else copy) */ MAD_FLAG_PADDING = 0x0080, /* frame has additional slot */ MAD_FLAG_I_STEREO = 0x0100, /* uses intensity joint stereo */ MAD_FLAG_MS_STEREO = 0x0200, /* uses middle/side joint stereo */ MAD_FLAG_FREEFORMAT = 0x0400, /* uses free format bitrate */ MAD_FLAG_LSF_EXT = 0x1000, /* lower sampling freq. extension */ MAD_FLAG_MC_EXT = 0x2000, /* multichannel audio extension */ MAD_FLAG_MPEG_2_5_EXT = 0x4000 /* MPEG 2.5 (unofficial) extension */ }; enum { MAD_PRIVATE_HEADER = 0x0100, /* header private bit */ MAD_PRIVATE_III = 0x001f /* Layer III private bits (up to 5) */ }; void mad_header_init(struct mad_header *); # define mad_header_finish(header) /* nothing */ int mad_header_decode(struct mad_header *, struct mad_stream *); void mad_frame_init(struct mad_frame *); void mad_frame_finish(struct mad_frame *); int mad_frame_decode(struct mad_frame *, struct mad_stream *); void mad_frame_mute(struct mad_frame *); # endif