X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Flzwenc.c;h=df38116c0db8cff795628d3d39b9192cfdc8bafd;hb=4320a309ce10a7eec93aef239a0776a33b1a5a34;hp=5b448953c83f5bb5f99067be63da36304a5a75f1;hpb=f0790c59f4485f32eace69ab68b53f097a617a8d;p=ffmpeg

diff --git a/libavcodec/lzwenc.c b/libavcodec/lzwenc.c
index 5b448953c83..df38116c0db 100644
--- a/libavcodec/lzwenc.c
+++ b/libavcodec/lzwenc.c
@@ -2,31 +2,31 @@
  * LZW encoder
  * Copyright (c) 2007 Bartlomiej Wolowiec
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
  * LZW encoder
- * @file lzwenc.c
+ * @file
  * @author Bartlomiej Wolowiec
  */
 
 #include "avcodec.h"
-#include "bitstream.h"
+#include "put_bits.h"
 #include "lzw.h"
 
 #define LZW_MAXBITS 12
@@ -58,6 +58,8 @@ typedef struct LZWEncodeState {
     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
+    enum FF_LZW_MODES mode;  ///< TIFF or GIF
+    void (*put_bits)(PutBitContext *, int, unsigned); ///< GIF is LE while TIFF is BE
 }LZWEncodeState;
 
 
@@ -110,7 +112,7 @@ static inline int hashOffset(const int head)
 static inline void writeCode(LZWEncodeState * s, int c)
 {
     assert(0 <= c && c < 1 << s->bits);
-    put_bits(&s->pb, s->bits, c);
+    s->put_bits(&s->pb, s->bits, c);
 }
 
 
@@ -151,7 +153,7 @@ static inline void addCode(LZWEncodeState * s, uint8_t c, int hash_prefix, int h
 
     s->tabsize++;
 
-    if (s->tabsize >= 1 << s->bits)
+    if (s->tabsize >= (1 << s->bits) + (s->mode == FF_LZW_GIF))
         s->bits++;
 }
 
@@ -183,7 +185,7 @@ static void clearTable(LZWEncodeState * s)
  * @return Number of bytes written
  */
 static int writtenBytes(LZWEncodeState *s){
-    int ret = (put_bits_count(&s->pb)) >> 3;
+    int ret = put_bits_count(&s->pb) >> 3;
     ret -= s->output_bytes;
     s->output_bytes += ret;
     return ret;
@@ -196,18 +198,22 @@ static int writtenBytes(LZWEncodeState *s){
  * @param outsize Size of output buffer
  * @param maxbits Maximum length of code
  */
-void ff_lzw_encode_init(LZWEncodeState * s, uint8_t * outbuf, int outsize, int maxbits)
+void ff_lzw_encode_init(LZWEncodeState *s, uint8_t *outbuf, int outsize,
+                        int maxbits, enum FF_LZW_MODES mode,
+                        void (*lzw_put_bits)(PutBitContext *, int, unsigned))
 {
     s->clear_code = 256;
     s->end_code = 257;
     s->maxbits = maxbits;
     init_put_bits(&s->pb, outbuf, outsize);
     s->bufsize = outsize;
-    assert(9 <= s->maxbits && s->maxbits <= s->maxbits);
+    assert(s->maxbits >= 9 && s->maxbits <= LZW_MAXBITS);
     s->maxcode = 1 << s->maxbits;
     s->output_bytes = 0;
     s->last_code = LZW_PREFIX_EMPTY;
     s->bits = 9;
+    s->mode = mode;
+    s->put_bits = lzw_put_bits;
 }
 
 /**
@@ -220,30 +226,27 @@ void ff_lzw_encode_init(LZWEncodeState * s, uint8_t * outbuf, int outsize, int m
 int ff_lzw_encode(LZWEncodeState * s, const uint8_t * inbuf, int insize)
 {
     int i;
-    int code_prefix = s->last_code;
 
     if(insize * 3 > (s->bufsize - s->output_bytes) * 2){
         return -1;
     }
 
-    if (code_prefix == LZW_PREFIX_EMPTY)
+    if (s->last_code == LZW_PREFIX_EMPTY)
         clearTable(s);
 
     for (i = 0; i < insize; i++) {
         uint8_t c = *inbuf++;
-        int code = findCode(s, c, code_prefix);
-        if (s->tab[code].hash_prefix != LZW_PREFIX_FREE) {
-            code_prefix = s->tab[code].code;
-        } else {
-            writeCode(s, code_prefix);
-            addCode(s, c, code_prefix, code);
-            code_prefix = s->tab[hash(0, c)].code;
+        int code = findCode(s, c, s->last_code);
+        if (s->tab[code].hash_prefix == LZW_PREFIX_FREE) {
+            writeCode(s, s->last_code);
+            addCode(s, c, s->last_code, code);
+            code= hash(0, c);
         }
+        s->last_code = s->tab[code].code;
         if (s->tabsize >= s->maxcode - 1) {
             clearTable(s);
         }
     }
-    s->last_code = code_prefix;
 
     return writtenBytes(s);
 }
@@ -253,12 +256,13 @@ int ff_lzw_encode(LZWEncodeState * s, const uint8_t * inbuf, int insize)
  * @param s LZW state
  * @return Number of bytes written or -1 on error
  */
-int ff_lzw_encode_flush(LZWEncodeState * s)
+int ff_lzw_encode_flush(LZWEncodeState *s,
+                        void (*lzw_flush_put_bits)(PutBitContext *))
 {
     if (s->last_code != -1)
         writeCode(s, s->last_code);
     writeCode(s, s->end_code);
-    flush_put_bits(&s->pb);
+    lzw_flush_put_bits(&s->pb);
     s->last_code = -1;
 
     return writtenBytes(s);