Merge pull request #975 from wjp/bitstream

Rework and optimize Common::BitStream

1 files changed, 33 insertions, 4 deletions

diff --git a/image/codecs/indeo/get_bits.h b/image/codecs/indeo/get_bits.h
index 359d8fcab0..f972e68ae0 100644
--- a/image/codecs/indeo/get_bits.h
+++ b/image/codecs/indeo/get_bits.h
@@ -31,15 +31,14 @@ namespace Indeo {
 /**
  * Intel Indeo Bitstream reader
  */
-class GetBits : public Common::BitStream8LSB {
+class GetBits : public Common::BitStreamMemory8LSB {
 public:
 	/**
 	* Constructor
 	* @param stream				Source stream to reader from
 	* @param disposeAfterUse	Whether to destroy stream in destructor
 	*/
-	GetBits(Common::SeekableReadStream *stream, DisposeAfterUse::Flag disposeAfterUse
-		= DisposeAfterUse::YES) : Common::BitStream8LSB(stream, disposeAfterUse) {}
+	GetBits(const uint8 *ptr, uint32 size) : Common::BitStreamMemory8LSB(new Common::BitStreamMemoryStream(ptr, size), DisposeAfterUse::YES) {}
 
 	/**
 	 * The number of bits left
@@ -54,7 +53,37 @@ public:
 	 *                  read the longest vlc code
 	 *                  = (max_vlc_length + bits - 1) / bits
 	 */
-	int getVLC2(int16 (*table)[2], int bits, int maxDepth);
+	template <int maxDepth>
+	int getVLC2(int16 (*table)[2], int bits) {
+		int code;
+		int n, nbBits;
+		unsigned int index;
+
+		index = peekBits(bits);
+		code  = table[index][0];
+		n     = table[index][1];
+
+		if (maxDepth > 1 && n < 0) {
+			skip(bits);
+			nbBits = -n;
+
+			index = peekBits(nbBits) + code;
+			code = table[index][0];
+			n = table[index][1];
+
+			if (maxDepth > 2 && n < 0) {
+				skip(nbBits);
+				nbBits = -n;
+
+				index = peekBits(nbBits) + code;
+				code = table[index][0];
+				n = table[index][1];
+			}
+		}
+
+		skip(n);
+		return code;
+	}
 };
 
 } // End of namespace Indeo