move get_unary() to its own file

Originally committed as revision 10240 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 72 insertions, 0 deletions

diff --git a/libavcodec/unary.h b/libavcodec/unary.h
new file mode 100644
index 0000000000..195e69f906
--- /dev/null
+++ b/libavcodec/unary.h
@@ -0,0 +1,72 @@
+/*
+ * copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_UNARY_H
+#define AVCODEC_UNARY_H
+
+#include "bitstream.h"
+
+/**
+ * Get unary code of limited length
+ * @todo FIXME Slow and ugly
+ * @param gb GetBitContext
+ * @param[in] stop The bitstop value (unary code of 1's or 0's)
+ * @param[in] len Maximum length
+ * @return Unary length/index
+ */
+static int get_unary(GetBitContext *gb, int stop, int len)
+{
+#if 1
+    int i;
+
+    for(i = 0; i < len && get_bits1(gb) != stop; i++);
+    return i;
+/*  int i = 0, tmp = !stop;
+
+  while (i != len && tmp != stop)
+  {
+    tmp = get_bits(gb, 1);
+    i++;
+  }
+  if (i == len && tmp != stop) return len+1;
+  return i;*/
+#else
+  unsigned int buf;
+  int log;
+
+  OPEN_READER(re, gb);
+  UPDATE_CACHE(re, gb);
+  buf=GET_CACHE(re, gb); //Still not sure
+  if (stop) buf = ~buf;
+
+  log= av_log2(-buf); //FIXME: -?
+  if (log < limit){
+    LAST_SKIP_BITS(re, gb, log+1);
+    CLOSE_READER(re, gb);
+    return log;
+  }
+
+  LAST_SKIP_BITS(re, gb, limit);
+  CLOSE_READER(re, gb);
+  return limit;
+#endif
+}
+
+#endif /* AVCODEC_UNARY_H */