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+/*! @file vlc.h
+ *
+ *  @brief Declaration of the data structures for variable-length decoding
+ *
+ *  @version 1.0.0
+ *
+ *  (C) Copyright 2018 GoPro Inc (http://gopro.com/).
+ *
+ *  Licensed under either:
+ *  - Apache License, Version 2.0, http://www.apache.org/licenses/LICENSE-2.0
+ *  - MIT license, http://opensource.org/licenses/MIT
+ *  at your option.
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+#ifndef VLC_H
+#define VLC_H
+
+// Codewords for the sign bits that follow a non-zero value
+#define VLC_POSITIVE_CODE 0x0		//!< Code that indicates a positive value
+#define VLC_NEGATIVE_CODE 0x1		//!< Code that indicates a negative value
+#define VLC_SIGNCODE_SIZE 1			//!< Size of the code for sign suffix
+
+/*!
+	@brief Codebook entries for arbitrary runs and values
+
+	The codebook data structure allows runs of an arbitrary value,
+	but all codec implementations only use runs of zeros.  The
+	codeword for a non-zero value is followed by the sign bit.
+
+	@todo Could add the sign bit to the magnitude entries in this
+	table if it improves performance or makes the code more clear.
+*/
+typedef struct _rlv {
+	uint_fast8_t size;		//!< Size of code word in bits
+	uint32_t bits;			//!< Code word bits right justified
+	uint32_t count;			//!< Run length
+	int32_t value;			//!< Run value (unsigned)
+} RLV;
+
+/*!
+	@brief Declaration of a codebook
+
+	This data structure is often called the master codebook to distinguish
+	it from the encoding tables that are derived from the codebook.  The
+	codebook has a header that is immediately followed by the codebook entries.
+	Each entry is an @ref RLV data structure that contains the codeword and
+	the size of the codeword in bits.  Each codeword represent a run length
+	and value.  The current codec implementation only supports runs of zeros,
+	so the run length is one for non-zero values.  A non-zero value is an
+	unsigned coefficient magnitude.  Special codewords that mark significant
+	locations in the bitstream are indicated by a run length of zero and the
+	value indicates the type of marker.
+
+	The codebook is generated by a separate program that takes as input a table
+	of the frequencies of coefficient magnitudes and runs of zeros.
+*/
+typedef struct _codebook
+{
+	uint32_t length;		//!< Number of entries in the code book
+							// The length is followed by the RLV entries
+} CODEBOOK;
+
+//! Macro used to define the codebook generated by the Huffman program
+#define RLVTABLE(n)			\
+	static struct			\
+	{						\
+		uint32_t length;	\
+		RLV entries[n];		\
+	}
+
+/*!
+	@brief Structure returned by the run length decoding routines
+
+	The value returned may be signed if the routine that was called
+	to parse the bitstream found a run of a non-zero value and then
+	parsed the sign bit that follows the magnitude.
+*/
+typedef struct _run {
+	uint32_t count;			//!< Run length count
+	int32_t value;			//!< Run length value
+} RUN;
+
+//! Initializer for the run length data structure
+#define RUN_INITIALIZER		{0, 0}
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+    CODEC_ERROR GetRlv(BITSTREAM *stream, CODEBOOK *codebook, RUN *run);
+    CODEC_ERROR GetRun(BITSTREAM *stream, CODEBOOK *codebook, RUN *run);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // VLC_H