1 files changed, 95 insertions, 0 deletions
diff --git a/contrib/a52dec/bitstream.c b/contrib/a52dec/bitstream.c
new file mode 100644
index 000000000..04e8ca6d0
--- /dev/null
+++ b/contrib/a52dec/bitstream.c
@@ -0,0 +1,95 @@
+/*
+ * bitstream.c
+ * Copyright (C) 2000-2002 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
+ */
+
+#include "config.h"
+
+#include <inttypes.h>
+
+#include "a52.h"
+#include "a52_internal.h"
+#include "bitstream.h"
+
+#define BUFFER_SIZE 4096
+
+void a52_bitstream_set_ptr (a52_state_t * state, uint8_t * buf)
+{
+    int align;
+
+    align = (long)buf & 3;
+    state->buffer_start = (uint32_t *) (buf - align);
+    state->bits_left = 0;
+    bitstream_get (state, align * 8);
+}
+
+static inline void bitstream_fill_current (a52_state_t * state)
+{
+    uint32_t tmp;
+
+    tmp = *(state->buffer_start++);
+    state->current_word = swab32 (tmp);
+}
+
+/*
+ * The fast paths for _get is in the
+ * bitstream.h header file so it can be inlined.
+ *
+ * The "bottom half" of this routine is suffixed _bh
+ *
+ * -ah
+ */
+
+uint32_t a52_bitstream_get_bh (a52_state_t * state, uint32_t num_bits)
+{
+    uint32_t result;
+
+    num_bits -= state->bits_left;
+    result = ((state->current_word << (32 - state->bits_left)) >>
+	      (32 - state->bits_left));
+
+    bitstream_fill_current (state);
+
+    if (num_bits != 0)
+	result = (result << num_bits) | (state->current_word >> (32 - num_bits));
+
+    state->bits_left = 32 - num_bits;
+
+    return result;
+}
+
+int32_t a52_bitstream_get_bh_2 (a52_state_t * state, uint32_t num_bits)
+{
+    int32_t result;
+
+    num_bits -= state->bits_left;
+    result = ((((int32_t)state->current_word) << (32 - state->bits_left)) >>
+	      (32 - state->bits_left));
+
+    bitstream_fill_current(state);
+
+    if (num_bits != 0)
+	result = (result << num_bits) | (state->current_word >> (32 - num_bits));
+	
+    state->bits_left = 32 - num_bits;
+
+    return result;
+}