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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: stream.h,v 1.3 2001-11-06 17:01:28 simons Exp $

 */

# ifndef LIBMAD_STREAM_H

# define LIBMAD_STREAM_H

# include "bit.h"

# define MAD_BUFFER_GUARD       8

# define MAD_BUFFER_MDLEN       (511 + 2048 + MAD_BUFFER_GUARD)

enum mad_error {

  MAD_ERROR_BUFLEN         = 0x0001,    /* input buffer too small (or EOF) */

  MAD_ERROR_BUFPTR         = 0x0002,    /* invalid (null) buffer pointer */

  MAD_ERROR_NOMEM          = 0x0031,    /* not enough memory */

  MAD_ERROR_LOSTSYNC       = 0x0101,    /* lost synchronization */

  MAD_ERROR_BADLAYER       = 0x0102,    /* reserved header layer value */

  MAD_ERROR_BADBITRATE     = 0x0103,    /* forbidden bitrate value */

  MAD_ERROR_BADSAMPLERATE  = 0x0104,    /* reserved sample frequency value */

  MAD_ERROR_BADEMPHASIS    = 0x0105,    /* reserved emphasis value */

  MAD_ERROR_BADCRC         = 0x0201,    /* CRC check failed */

  MAD_ERROR_BADBITALLOC    = 0x0211,    /* forbidden bit allocation value */

  MAD_ERROR_BADSCALEFACTOR = 0x0221,    /* bad scalefactor index */

  MAD_ERROR_BADFRAMELEN    = 0x0231,    /* bad frame length */

  MAD_ERROR_BADBIGVALUES   = 0x0232,    /* bad big_values count */

  MAD_ERROR_BADBLOCKTYPE   = 0x0233,    /* reserved block_type */

  MAD_ERROR_BADSCFSI       = 0x0234,    /* bad scalefactor selection info */

  MAD_ERROR_BADDATAPTR     = 0x0235,    /* bad main_data_begin pointer */

  MAD_ERROR_BADPART3LEN    = 0x0236,    /* bad audio data length */

  MAD_ERROR_BADHUFFTABLE   = 0x0237,    /* bad Huffman table select */

  MAD_ERROR_BADHUFFDATA    = 0x0238,    /* Huffman data overrun */

  MAD_ERROR_BADSTEREO      = 0x0239     /* incompatible block_type for JS */

};

# define MAD_RECOVERABLE(error) ((error) & 0xff00)

struct mad_stream {

  unsigned char const *buffer;          /* input bitstream buffer */

  unsigned char const *bufend;          /* end of buffer */

  unsigned long skiplen;                /* bytes to skip before next frame */

  int sync;                             /* stream sync found */

  unsigned long freerate;               /* free bitrate (fixed) */

  unsigned char const *this_frame;      /* start of current frame */

  unsigned char const *next_frame;      /* start of next frame */

  struct mad_bitptr ptr;                /* current processing bit pointer */

  struct mad_bitptr anc_ptr;            /* ancillary bits pointer */

  unsigned int anc_bitlen;              /* number of ancillary bits */

  unsigned char (*main_data);

                                        /* Layer III main_data() */

  unsigned int md_len;                  /* bytes in main_data */

  int options;                          /* decoding options (see below) */

  enum mad_error error;                 /* error code (see above) */

};

enum {

  MAD_OPTION_IGNORECRC      = 0x0001,   /* ignore CRC errors */

  MAD_OPTION_HALFSAMPLERATE = 0x0002,   /* generate PCM at 1/2 sample rate */

# if 0  /* not yet implemented */

  MAD_OPTION_LEFTCHANNEL    = 0x0010,   /* decode left channel only */

  MAD_OPTION_RIGHTCHANNEL   = 0x0020,   /* decode right channel only */

  MAD_OPTION_SINGLECHANNEL  = 0x0030,   /* combine channels */

# endif

};

void mad_stream_init(struct mad_stream *);

void mad_stream_finish(struct mad_stream *);

# define mad_stream_options(stream, opts)  ((stream)->options = (opts))

void mad_stream_buffer(struct mad_stream *,

                       unsigned char const *, unsigned long);

void mad_stream_skip(struct mad_stream *, unsigned long);

int mad_stream_sync(struct mad_stream *);

# endif