1 /* 2 * libmad - MPEG audio decoder library 3 * Copyright (C) 2000-2004 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 * $Id: stream.h,v 1.20 2004/02/05 09:02:39 rob Exp $ 20 */ 21 22 # ifndef LIBMAD_STREAM_H 23 # define LIBMAD_STREAM_H 24 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_BADMODE = 0x0222, /* bad bitrate/mode combination */ 48 MAD_ERROR_BADFRAMELEN = 0x0231, /* bad frame length */ 49 MAD_ERROR_BADBIGVALUES = 0x0232, /* bad big_values count */ 50 MAD_ERROR_BADBLOCKTYPE = 0x0233, /* reserved block_type */ 51 MAD_ERROR_BADSCFSI = 0x0234, /* bad scalefactor selection info */ 52 MAD_ERROR_BADDATAPTR = 0x0235, /* bad main_data_begin pointer */ 53 MAD_ERROR_BADPART3LEN = 0x0236, /* bad audio data length */ 54 MAD_ERROR_BADHUFFTABLE = 0x0237, /* bad Huffman table select */ 55 MAD_ERROR_BADHUFFDATA = 0x0238, /* Huffman data overrun */ 56 MAD_ERROR_BADSTEREO = 0x0239 /* incompatible block_type for JS */ 57 }; 58 59 # define MAD_RECOVERABLE(error) ((error) & 0xff00) 60 61 struct mad_stream { 62 unsigned char const *buffer; /* input bitstream buffer */ 63 unsigned char const *bufend; /* end of buffer */ 64 unsigned long skiplen; /* bytes to skip before next frame */ 65 66 int sync; /* stream sync found */ 67 unsigned long freerate; /* free bitrate (fixed) */ 68 69 unsigned char const *this_frame; /* start of current frame */ 70 unsigned char const *next_frame; /* start of next frame */ 71 struct mad_bitptr ptr; /* current processing bit pointer */ 72 73 struct mad_bitptr anc_ptr; /* ancillary bits pointer */ 74 unsigned int anc_bitlen; /* number of ancillary bits */ 75 76 unsigned char (*main_data)[MAD_BUFFER_MDLEN]; 77 /* Layer III main_data() */ 78 unsigned int md_len; /* bytes in main_data */ 79 80 int options; /* decoding options (see below) */ 81 enum mad_error error; /* error code (see above) */ 82 }; 83 84 enum { 85 MAD_OPTION_IGNORECRC = 0x0001, /* ignore CRC errors */ 86 MAD_OPTION_HALFSAMPLERATE = 0x0002 /* generate PCM at 1/2 sample rate */ 87 # if 0 /* not yet implemented */ 88 MAD_OPTION_LEFTCHANNEL = 0x0010, /* decode left channel only */ 89 MAD_OPTION_RIGHTCHANNEL = 0x0020, /* decode right channel only */ 90 MAD_OPTION_SINGLECHANNEL = 0x0030 /* combine channels */ 91 # endif 92 }; 93 94 void mad_stream_init(struct mad_stream *); 95 void mad_stream_finish(struct mad_stream *); 96 97 # define mad_stream_options(stream, opts) \ 98 ((void) ((stream)->options = (opts))) 99 100 void mad_stream_buffer(struct mad_stream *, 101 unsigned char const *, unsigned long); 102 void mad_stream_skip(struct mad_stream *, unsigned long); 103 104 int mad_stream_sync(struct mad_stream *); 105 106 char const *mad_stream_errorstr(struct mad_stream const *); 107 108 # endif 109