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authorAlex Beregszaszi <alex@rtfs.hu>2007-08-08 20:38:30 +0000
committerAlex Beregszaszi <alex@rtfs.hu>2007-08-08 20:38:30 +0000
commit971e878dca0bc5b8323b120f55067a3191cc6d88 (patch)
treea78166c50c7709855891cc38c7c698d0e96885e4 /libavcodec
parentec5dc2c1af47e6f19e2bc482b3a1be09ba9e31bb (diff)
downloadffmpeg-971e878dca0bc5b8323b120f55067a3191cc6d88.tar.gz
copy get_unary from vc1
Originally committed as revision 9994 to svn://svn.ffmpeg.org/ffmpeg/trunk
Diffstat (limited to 'libavcodec')
-rw-r--r--libavcodec/bitstream.h46
1 files changed, 46 insertions, 0 deletions
diff --git a/libavcodec/bitstream.h b/libavcodec/bitstream.h
index c516c3c20b..d41d5ec60b 100644
--- a/libavcodec/bitstream.h
+++ b/libavcodec/bitstream.h
@@ -969,4 +969,50 @@ static inline int decode012(GetBitContext *gb){
return get_bits1(gb) + 1;
}
+/**
+ * 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 /* BITSTREAM_H */