--- /dev/null
+/*
+ * LZW decoder
+ * Copyright (c) 2003 Fabrice Bellard.
+ * Copyright (c) 2006 Konstantin Shishkov.
+ *
+ * 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 __CMS_LZW_H__
+#define __CMS_LZW_H__
+
+/*!\file cms_lzw.h
+ * \brief Header file for LZW Encoder/Decoder functions.
+ *
+ * These functions were taken from the ffmpeg library.
+ */
+
+
+#define LZW_MAXBITS 12
+#define LZW_SIZTABLE (1<<LZW_MAXBITS)
+#define LZW_HASH_SIZE 16411
+#define LZW_HASH_SHIFT 6
+
+#define LZW_PREFIX_EMPTY -1
+#define LZW_PREFIX_FREE -2
+
+
+/** fixed length header in front of compressed config file */
+#define COMPRESSED_CONFIG_HEADER_LENGTH 40
+
+/** start of compressed config file */
+#define COMPRESSED_CONFIG_HEADER "<compressed alg=lzw len="
+
+
+/** One code in hash table */
+typedef struct Code{
+ /// Hash code of prefix, LZW_PREFIX_EMPTY if empty prefix, or LZW_PREFIX_FREE if no code
+ int hash_prefix;
+ int code; ///< LZW code
+ uint8_t suffix; ///< Last character in code block
+}Code;
+
+
+typedef struct PutBitContext {
+ uint32_t bit_buf;
+ int bit_left;
+ uint8_t *buf, *buf_ptr, *buf_end;
+} PutBitContext;
+
+
+/** LZW encode state */
+typedef struct {
+ int clear_code; ///< Value of clear code
+ int end_code; ///< Value of end code
+ Code tab[LZW_HASH_SIZE]; ///< Hash table
+ int tabsize; ///< Number of values in hash table
+ int bits; ///< Actual bits code
+ int bufsize; ///< Size of output buffer
+ PutBitContext pb; ///< Put bit context for output
+ int maxbits; ///< Max bits code
+ int maxcode; ///< Max value of code
+ int output_bytes; ///< Number of written bytes
+ int last_code; ///< Value of last output code or LZW_PREFIX_EMPTY
+}LZWEncoderState;
+
+
+/** LZW decoder state structure */
+typedef struct {
+ uint8_t *pbuf, *ebuf;
+ int bbits;
+ unsigned int bbuf;
+
+ int mode; ///< Decoder mode
+ int cursize; ///< The current code size
+ int curmask;
+ int codesize;
+ int clear_code;
+ int end_code;
+ int newcodes; ///< First available code
+ int top_slot; ///< Highest code for current size
+ int extra_slot;
+ int slot; ///< Last read code
+ int fc, oc;
+ uint8_t *sp;
+ uint8_t stack[LZW_SIZTABLE];
+ uint8_t suffix[LZW_SIZTABLE];
+ uint16_t prefix[LZW_SIZTABLE];
+ int bs; ///< current buffer size for GIF
+} LZWDecoderState;
+
+
+/** Create and Initialize a LZW encoder.
+ *
+ * @param s (IN/OUT) LZW encoder state structure allocated by this function.
+ * @param outbuf (IN) Output buffer, caller is responsible for allocating the buffer.
+ * @param outsize (IN) Size of output buffer
+ *
+ * @return CmsRet enum
+ */
+CmsRet cmsLzw_initEncoder(LZWEncoderState **s, UINT8 *outbuf, UINT32 outsize);
+
+
+/** LZW main encode/compress function
+ *
+ * @param s (IN) LZW encoder state
+ * @param inbuf (IN) Input buffer, contains data to be compressed
+ * @param insize (IN) Size of input buffer
+ * @return Number of bytes written or -1 on error
+ */
+SINT32 cmsLzw_encode(LZWEncoderState *s, const UINT8 *inbuf, UINT32 insize);
+
+
+/** Write end code and flush bitstream
+ *
+ * @param s (IN) LZW encoder state
+ * @return Number of bytes written or -1 on error. Note the count here should
+ * be added to the count returned by cmsLzw_encode for the total number
+ * of encoded/compressed bytes.
+ */
+SINT32 cmsLzw_flushEncoder(LZWEncoderState *s);
+
+
+/** Destroy the LZW encoder.
+ * Note the output buffer that was passed into the cmsLzw_initEncoder
+ * is not freed. That buffer is the responsibility of the caller.
+ *
+ * @param s (IN) LZW encoder state
+ */
+void cmsLzw_cleanupEncoder(LZWEncoderState **s);
+
+
+/** Create and Initialize a LZW decoder
+ *
+ * @param s (IN/OUT) LZW decoder context
+ * @param inbuf (IN) input compressed data
+ * @param inbuf_size (IN) input data size
+ *
+ * @return CmsRet enum
+ */
+CmsRet cmsLzw_initDecoder(LZWDecoderState **s, UINT8 *inbuf, UINT32 inbuf_size);
+
+
+/** Decode given number of bytes
+ *
+ * @param s (IN) LZW decoder context
+ * @param outbuf (IN) output buffer, caller is responsible for allocating this buffer
+ * @param outlen (IN) number of bytes to decode, or the length of the output buffer.
+ * The decompressor/decoder will stop if the end of the encoded
+ * data is reached or if the end of the output buffer is reached.
+ *
+ * @return number of bytes decoded, or -1 on error.
+ */
+SINT32 cmsLzw_decode(LZWDecoderState *s, UINT8 *outbuf, UINT32 outlen);
+
+
+/** Destroy the LZW Decoder.
+ *
+ * Note the input buffer that was passed into cmsLzw_initDecoder is not freed.
+ * That buffer is the responsibility of the caller.
+ */
+void cmsLzw_cleanupDecoder(LZWDecoderState **s);
+
+
+
+#endif /* __CMS_LZW_H__ */
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