diff options
Diffstat (limited to 'libmad/src/stream.c')
| -rw-r--r-- | libmad/src/stream.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/libmad/src/stream.c b/libmad/src/stream.c new file mode 100644 index 0000000..8bb4d6a --- /dev/null +++ b/libmad/src/stream.c @@ -0,0 +1,161 @@ +/* + * libmad - MPEG audio decoder library + * Copyright (C) 2000-2004 Underbit Technologies, Inc. + * + * 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.c,v 1.12 2004/02/05 09:02:39 rob Exp $ + */ + +# ifdef HAVE_CONFIG_H +# include "config.h" +# endif + +# include "global.h" + +# include <stdlib.h> + +# include "bit.h" +# include "stream.h" + +/* + * NAME: stream->init() + * DESCRIPTION: initialize stream struct + */ +void mad_stream_init(struct mad_stream *stream) +{ + stream->buffer = 0; + stream->bufend = 0; + stream->skiplen = 0; + + stream->sync = 0; + stream->freerate = 0; + + stream->this_frame = 0; + stream->next_frame = 0; + mad_bit_init(&stream->ptr, 0); + + mad_bit_init(&stream->anc_ptr, 0); + stream->anc_bitlen = 0; + + stream->main_data = 0; + stream->md_len = 0; + + stream->options = 0; + stream->error = MAD_ERROR_NONE; +} + +/* + * NAME: stream->finish() + * DESCRIPTION: deallocate any dynamic memory associated with stream + */ +void mad_stream_finish(struct mad_stream *stream) +{ + if (stream->main_data) { + free(stream->main_data); + stream->main_data = 0; + } + + mad_bit_finish(&stream->anc_ptr); + mad_bit_finish(&stream->ptr); +} + +/* + * NAME: stream->buffer() + * DESCRIPTION: set stream buffer pointers + */ +void mad_stream_buffer(struct mad_stream *stream, + unsigned char const *buffer, unsigned long length) +{ + stream->buffer = buffer; + stream->bufend = buffer + length; + + stream->this_frame = buffer; + stream->next_frame = buffer; + + stream->sync = 1; + + mad_bit_init(&stream->ptr, buffer); +} + +/* + * NAME: stream->skip() + * DESCRIPTION: arrange to skip bytes before the next frame + */ +void mad_stream_skip(struct mad_stream *stream, unsigned long length) +{ + stream->skiplen += length; +} + +/* + * NAME: stream->sync() + * DESCRIPTION: locate the next stream sync word + */ +int mad_stream_sync(struct mad_stream *stream) +{ + register unsigned char const *ptr, *end; + + ptr = mad_bit_nextbyte(&stream->ptr); + end = stream->bufend; + + while (ptr < end - 1 && + !(ptr[0] == 0xff && (ptr[1] & 0xe0) == 0xe0)) + ++ptr; + + if (end - ptr < MAD_BUFFER_GUARD) + return -1; + + mad_bit_init(&stream->ptr, ptr); + + return 0; +} + +/* + * NAME: stream->errorstr() + * DESCRIPTION: return a string description of the current error condition + */ +char const *mad_stream_errorstr(struct mad_stream const *stream) +{ + switch (stream->error) { + case MAD_ERROR_NONE: return "no error"; + + case MAD_ERROR_BUFLEN: return "input buffer too small (or EOF)"; + case MAD_ERROR_BUFPTR: return "invalid (null) buffer pointer"; + + case MAD_ERROR_NOMEM: return "not enough memory"; + + case MAD_ERROR_LOSTSYNC: return "lost synchronization"; + case MAD_ERROR_BADLAYER: return "reserved header layer value"; + case MAD_ERROR_BADBITRATE: return "forbidden bitrate value"; + case MAD_ERROR_BADSAMPLERATE: return "reserved sample frequency value"; + case MAD_ERROR_BADEMPHASIS: return "reserved emphasis value"; + + case MAD_ERROR_BADCRC: return "CRC check failed"; + case MAD_ERROR_BADBITALLOC: return "forbidden bit allocation value"; + case MAD_ERROR_BADSCALEFACTOR: return "bad scalefactor index"; + case MAD_ERROR_BADMODE: return "bad bitrate/mode combination"; + case MAD_ERROR_BADFRAMELEN: return "bad frame length"; + case MAD_ERROR_BADBIGVALUES: return "bad big_values count"; + case MAD_ERROR_BADBLOCKTYPE: return "reserved block_type"; + case MAD_ERROR_BADSCFSI: return "bad scalefactor selection info"; + case MAD_ERROR_BADDATAPTR: return "bad main_data_begin pointer"; + case MAD_ERROR_BADPART3LEN: return "bad audio data length"; + case MAD_ERROR_BADHUFFTABLE: return "bad Huffman table select"; + case MAD_ERROR_BADHUFFDATA: return "Huffman data overrun"; + case MAD_ERROR_BADSTEREO: return "incompatible block_type for JS"; + } + + return 0; +} |