X-Git-Url: https://iam.tj/gitweb/gitweb.cgi?p=firmware_extractor.git;a=blobdiff_plain;f=cms_lzw.h;fp=cms_lzw.h;h=9dd8d4ddaacd856414a85ca4150f3102363d79b6;hp=0000000000000000000000000000000000000000;hb=1693f804f61fb9856114c39185ea3eb46e3f93e5;hpb=471193f5356782a85ea6378fd4355db97930d122

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+/*
+ * 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__ */