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/*

 * mad - MPEG audio decoder

 * Copyright (C) 2000-2001 Robert Leslie

 *

 * 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 1.3 2001-11-06 17:01:28 simons Exp $

 */

# ifndef LIBMAD_FRAME_H

# define LIBMAD_FRAME_H

# include "fixed.h"

# include "timer.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 */

};

struct mad_frame {

  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) */

    mad_timer_t duration;               /* audio playing time of frame */

  } 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