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-rw-r--r--liba52/bitstream.h82
1 files changed, 82 insertions, 0 deletions
diff --git a/liba52/bitstream.h b/liba52/bitstream.h
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+++ b/liba52/bitstream.h
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+/*
+ * bitstream.h
+ * Copyright (C) 2000-2001 Michel Lespinasse <walken@zoy.org>
+ * Copyright (C) 1999-2000 Aaron Holtzman <aholtzma@ess.engr.uvic.ca>
+ *
+ * This file is part of a52dec, a free ATSC A-52 stream decoder.
+ * See http://liba52.sourceforge.net/ for updates.
+ *
+ * a52dec 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.
+ *
+ * a52dec 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
+ */
+
+/* (stolen from the kernel) */
+#ifdef WORDS_BIGENDIAN
+
+# define swab32(x) (x)
+
+#else
+
+# if defined (__i386__)
+
+# define swab32(x) __i386_swab32(x)
+ static inline const uint32_t __i386_swab32(uint32_t x)
+ {
+ __asm__("bswap %0" : "=r" (x) : "0" (x));
+ return x;
+ }
+
+# else
+
+# define swab32(x)\
+((((uint8_t*)&x)[0] << 24) | (((uint8_t*)&x)[1] << 16) | \
+ (((uint8_t*)&x)[2] << 8) | (((uint8_t*)&x)[3]))
+
+# endif
+#endif
+
+extern uint32_t bits_left;
+extern uint32_t current_word;
+
+void bitstream_set_ptr (uint8_t * buf);
+uint32_t bitstream_get_bh(uint32_t num_bits);
+int32_t bitstream_get_bh_2(uint32_t num_bits);
+
+static inline uint32_t
+bitstream_get(uint32_t num_bits)
+{
+ uint32_t 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);
+}
+
+static inline int32_t
+bitstream_get_2(uint32_t num_bits)
+{
+ int32_t result;
+
+ if(num_bits < bits_left) {
+ result = (((int32_t)current_word) << (32 - bits_left)) >> (32 - num_bits);
+ bits_left -= num_bits;
+ return result;
+ }
+
+ return bitstream_get_bh_2(num_bits);
+}