libmad/stream.h

   1 /*
   2  * libmad - MPEG audio decoder library
   3  * Copyright (C) 2000-2003 Underbit Technologies, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  *
  19  */
  20
  21 # ifndef LIBMAD_STREAM_H
  22 # define LIBMAD_STREAM_H
  23
  24 #include <gctypes.h>
  25 # include "bit.h"
  26
  27 # define MAD_BUFFER_GUARD       8
  28 # define MAD_BUFFER_MDLEN       (511 + 2048 + MAD_BUFFER_GUARD)
  29
  30 enum mad_error {
  31   MAD_ERROR_NONE           = 0x0000,    /* no error */
  32
  33   MAD_ERROR_BUFLEN         = 0x0001,    /* input buffer too small (or EOF) */
  34   MAD_ERROR_BUFPTR         = 0x0002,    /* invalid (null) buffer pointer */
  35
  36   MAD_ERROR_NOMEM          = 0x0031,    /* not enough memory */
  37
  38   MAD_ERROR_LOSTSYNC       = 0x0101,    /* lost synchronization */
  39   MAD_ERROR_BADLAYER       = 0x0102,    /* reserved header layer value */
  40   MAD_ERROR_BADBITRATE     = 0x0103,    /* forbidden bitrate value */
  41   MAD_ERROR_BADSAMPLERATE  = 0x0104,    /* reserved sample frequency value */
  42   MAD_ERROR_BADEMPHASIS    = 0x0105,    /* reserved emphasis value */
  43
  44   MAD_ERROR_BADCRC         = 0x0201,    /* CRC check failed */
  45   MAD_ERROR_BADBITALLOC    = 0x0211,    /* forbidden bit allocation value */
  46   MAD_ERROR_BADSCALEFACTOR = 0x0221,    /* bad scalefactor index */
  47   MAD_ERROR_BADFRAMELEN    = 0x0231,    /* bad frame length */
  48   MAD_ERROR_BADBIGVALUES   = 0x0232,    /* bad big_values count */
  49   MAD_ERROR_BADBLOCKTYPE   = 0x0233,    /* reserved block_type */
  50   MAD_ERROR_BADSCFSI       = 0x0234,    /* bad scalefactor selection info */
  51   MAD_ERROR_BADDATAPTR     = 0x0235,    /* bad main_data_begin pointer */
  52   MAD_ERROR_BADPART3LEN    = 0x0236,    /* bad audio data length */
  53   MAD_ERROR_BADHUFFTABLE   = 0x0237,    /* bad Huffman table select */
  54   MAD_ERROR_BADHUFFDATA    = 0x0238,    /* Huffman data overrun */
  55   MAD_ERROR_BADSTEREO      = 0x0239     /* incompatible block_type for JS */
  56 };
  57
  58 # define MAD_RECOVERABLE(error) ((error) & 0xff00)
  59
  60 struct mad_stream {
  61   u8 const *buffer;             /* input bitstream buffer */
  62   u8 const *bufend;             /* end of buffer */
  63   u32 skiplen;          /* bytes to skip before next frame */
  64
  65   s32 sync;                             /* stream sync found */
  66   u32 freerate;         /* free bitrate (fixed) */
  67
  68   u8 const *this_frame; /* start of current frame */
  69   u8 const *next_frame; /* start of next frame */
  70   struct mad_bitptr ptr;                /* current processing bit pointer */
  71
  72   struct mad_bitptr anc_ptr;            /* ancillary bits pointer */
  73   u32 anc_bitlen;               /* number of ancillary bits */
  74
  75   u8 (*main_data)[MAD_BUFFER_MDLEN];
  76                                         /* Layer III main_data() */
  77   u32 md_len;                   /* bytes in main_data */
  78
  79   s32 options;                          /* decoding options (see below) */
  80   enum mad_error error;                 /* error code (see above) */
  81 };
  82
  83 enum {
  84   MAD_OPTION_IGNORECRC      = 0x0001,   /* ignore CRC errors */
  85   MAD_OPTION_HALFSAMPLERATE = 0x0002    /* generate PCM at 1/2 sample rate */
  86 # if 0  /* not yet implemented */
  87   MAD_OPTION_LEFTCHANNEL    = 0x0010,   /* decode left channel only */
  88   MAD_OPTION_RIGHTCHANNEL   = 0x0020,   /* decode right channel only */
  89   MAD_OPTION_SINGLECHANNEL  = 0x0030    /* combine channels */
  90 # endif
  91 };
  92
  93 void mad_stream_init(struct mad_stream *);
  94 void mad_stream_finish(struct mad_stream *);
  95
  96 # define mad_stream_options(stream, opts)  \
  97     ((void) ((stream)->options = (opts)))
  98
  99 void mad_stream_buffer(struct mad_stream *,
 100                        u8 const *, u32);
 101 void mad_stream_skip(struct mad_stream *, u32);
 102
 103 s32 mad_stream_sync(struct mad_stream *);
 104
 105 char const *mad_stream_errorstr(struct mad_stream const *);
 106
 107 # endif