summaryrefslogtreecommitdiff
path: root/ac3dec/bitstream.h
diff options
context:
space:
mode:
Diffstat (limited to 'ac3dec/bitstream.h')
-rw-r--r--ac3dec/bitstream.h76
1 files changed, 76 insertions, 0 deletions
diff --git a/ac3dec/bitstream.h b/ac3dec/bitstream.h
new file mode 100644
index 0000000..3351930
--- /dev/null
+++ b/ac3dec/bitstream.h
@@ -0,0 +1,76 @@
+/*
+ * bitstream.h
+ *
+ * Copyright (C) Aaron Holtzman - Dec 1999
+ *
+ * This file is part of ac3dec, a free AC-3 audio decoder
+ *
+ * ac3dec 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, or (at your option)
+ * any later version.
+ *
+ * ac3dec 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 GNU Make; see the file COPYING. If not, write to
+ * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+//My new and improved vego-matic endian swapping routine
+//(stolen from the kernel)
+#ifdef WORDS_BIGENDIAN
+
+# define swab32(x) (x)
+
+#else
+
+# if defined (__i386__)
+
+# define swab32(x) __i386_swab32(x)
+ static inline const uint_32 __i386_swab32(uint_32 x)
+ {
+ __asm__("bswap %0" : "=r" (x) : "0" (x));
+ return x;
+ }
+
+# else
+
+# define swab32(x)\
+((((uint_8*)&x)[0] << 24) | (((uint_8*)&x)[1] << 16) | \
+ (((uint_8*)&x)[2] << 8) | (((uint_8*)&x)[3]))
+
+# endif
+#endif
+
+extern uint_32 bits_left;
+extern uint_32 current_word;
+
+void bitstream_init(uint_8 *start);
+
+uint_8 bitstream_get_byte(void);
+
+uint_8 *bitstream_get_buffer_start(void);
+void bitstream_buffer_frame(uint_32 frame_size);
+
+uint_32 bitstream_get_bh(uint_32 num_bits);
+
+static inline uint_32
+bitstream_get(uint_32 num_bits)
+{
+ uint_32 result;
+
+ if(num_bits < bits_left)
+ {
+ result = (current_word << (32 - bits_left)) >> (32 - num_bits);
+ bits_left -= num_bits;
+ return result;
+ }
+
+ return bitstream_get_bh(num_bits);
+}
+