comparison src/libmad-0.15.1b/stream.c @ 0:c7265573341e

Import initial set of sources

+/*
+ * 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;
+}