cannam@85: /*
cannam@85:  * libmad - MPEG audio decoder library
cannam@85:  * Copyright (C) 2000-2004 Underbit Technologies, Inc.
cannam@85:  *
cannam@85:  * This program is free software; you can redistribute it and/or modify
cannam@85:  * it under the terms of the GNU General Public License as published by
cannam@85:  * the Free Software Foundation; either version 2 of the License, or
cannam@85:  * (at your option) any later version.
cannam@85:  *
cannam@85:  * This program is distributed in the hope that it will be useful,
cannam@85:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
cannam@85:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
cannam@85:  * GNU General Public License for more details.
cannam@85:  *
cannam@85:  * You should have received a copy of the GNU General Public License
cannam@85:  * along with this program; if not, write to the Free Software
cannam@85:  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
cannam@85:  *
cannam@85:  * $Id: stream.h,v 1.20 2004/02/05 09:02:39 rob Exp $
cannam@85:  */
cannam@85: 
cannam@85: # ifndef LIBMAD_STREAM_H
cannam@85: # define LIBMAD_STREAM_H
cannam@85: 
cannam@85: # include "bit.h"
cannam@85: 
cannam@85: # define MAD_BUFFER_GUARD	8
cannam@85: # define MAD_BUFFER_MDLEN	(511 + 2048 + MAD_BUFFER_GUARD)
cannam@85: 
cannam@85: enum mad_error {
cannam@85:   MAD_ERROR_NONE	   = 0x0000,	/* no error */
cannam@85: 
cannam@85:   MAD_ERROR_BUFLEN	   = 0x0001,	/* input buffer too small (or EOF) */
cannam@85:   MAD_ERROR_BUFPTR	   = 0x0002,	/* invalid (null) buffer pointer */
cannam@85: 
cannam@85:   MAD_ERROR_NOMEM	   = 0x0031,	/* not enough memory */
cannam@85: 
cannam@85:   MAD_ERROR_LOSTSYNC	   = 0x0101,	/* lost synchronization */
cannam@85:   MAD_ERROR_BADLAYER	   = 0x0102,	/* reserved header layer value */
cannam@85:   MAD_ERROR_BADBITRATE	   = 0x0103,	/* forbidden bitrate value */
cannam@85:   MAD_ERROR_BADSAMPLERATE  = 0x0104,	/* reserved sample frequency value */
cannam@85:   MAD_ERROR_BADEMPHASIS	   = 0x0105,	/* reserved emphasis value */
cannam@85: 
cannam@85:   MAD_ERROR_BADCRC	   = 0x0201,	/* CRC check failed */
cannam@85:   MAD_ERROR_BADBITALLOC	   = 0x0211,	/* forbidden bit allocation value */
cannam@85:   MAD_ERROR_BADSCALEFACTOR = 0x0221,	/* bad scalefactor index */
cannam@85:   MAD_ERROR_BADMODE        = 0x0222,	/* bad bitrate/mode combination */
cannam@85:   MAD_ERROR_BADFRAMELEN	   = 0x0231,	/* bad frame length */
cannam@85:   MAD_ERROR_BADBIGVALUES   = 0x0232,	/* bad big_values count */
cannam@85:   MAD_ERROR_BADBLOCKTYPE   = 0x0233,	/* reserved block_type */
cannam@85:   MAD_ERROR_BADSCFSI	   = 0x0234,	/* bad scalefactor selection info */
cannam@85:   MAD_ERROR_BADDATAPTR	   = 0x0235,	/* bad main_data_begin pointer */
cannam@85:   MAD_ERROR_BADPART3LEN	   = 0x0236,	/* bad audio data length */
cannam@85:   MAD_ERROR_BADHUFFTABLE   = 0x0237,	/* bad Huffman table select */
cannam@85:   MAD_ERROR_BADHUFFDATA	   = 0x0238,	/* Huffman data overrun */
cannam@85:   MAD_ERROR_BADSTEREO	   = 0x0239	/* incompatible block_type for JS */
cannam@85: };
cannam@85: 
cannam@85: # define MAD_RECOVERABLE(error)	((error) & 0xff00)
cannam@85: 
cannam@85: struct mad_stream {
cannam@85:   unsigned char const *buffer;		/* input bitstream buffer */
cannam@85:   unsigned char const *bufend;		/* end of buffer */
cannam@85:   unsigned long skiplen;		/* bytes to skip before next frame */
cannam@85: 
cannam@85:   int sync;				/* stream sync found */
cannam@85:   unsigned long freerate;		/* free bitrate (fixed) */
cannam@85: 
cannam@85:   unsigned char const *this_frame;	/* start of current frame */
cannam@85:   unsigned char const *next_frame;	/* start of next frame */
cannam@85:   struct mad_bitptr ptr;		/* current processing bit pointer */
cannam@85: 
cannam@85:   struct mad_bitptr anc_ptr;		/* ancillary bits pointer */
cannam@85:   unsigned int anc_bitlen;		/* number of ancillary bits */
cannam@85: 
cannam@85:   unsigned char (*main_data)[MAD_BUFFER_MDLEN];
cannam@85: 					/* Layer III main_data() */
cannam@85:   unsigned int md_len;			/* bytes in main_data */
cannam@85: 
cannam@85:   int options;				/* decoding options (see below) */
cannam@85:   enum mad_error error;			/* error code (see above) */
cannam@85: };
cannam@85: 
cannam@85: enum {
cannam@85:   MAD_OPTION_IGNORECRC      = 0x0001,	/* ignore CRC errors */
cannam@85:   MAD_OPTION_HALFSAMPLERATE = 0x0002	/* generate PCM at 1/2 sample rate */
cannam@85: # if 0  /* not yet implemented */
cannam@85:   MAD_OPTION_LEFTCHANNEL    = 0x0010,	/* decode left channel only */
cannam@85:   MAD_OPTION_RIGHTCHANNEL   = 0x0020,	/* decode right channel only */
cannam@85:   MAD_OPTION_SINGLECHANNEL  = 0x0030	/* combine channels */
cannam@85: # endif
cannam@85: };
cannam@85: 
cannam@85: void mad_stream_init(struct mad_stream *);
cannam@85: void mad_stream_finish(struct mad_stream *);
cannam@85: 
cannam@85: # define mad_stream_options(stream, opts)  \
cannam@85:     ((void) ((stream)->options = (opts)))
cannam@85: 
cannam@85: void mad_stream_buffer(struct mad_stream *,
cannam@85: 		       unsigned char const *, unsigned long);
cannam@85: void mad_stream_skip(struct mad_stream *, unsigned long);
cannam@85: 
cannam@85: int mad_stream_sync(struct mad_stream *);
cannam@85: 
cannam@85: char const *mad_stream_errorstr(struct mad_stream const *);
cannam@85: 
cannam@85: # endif