Make strmatch() return 1 only if the string compared against the

[ffmpeg] / libavcodec / mjpegdec.c

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index fe08d7bd886b4e61a43462f513364e54078fb8b4..e57f74f3744cdd15c6b376ad3eff5bd0ba6df5f7 100644 (file)
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -57,6 +57,8 @@ static int build_vlc(VLC *vlc, const uint8_t *bits_table, const uint8_t *val_tab
     for(i=0; i<256; i++)
         huff_sym[i]= i + 16*is_ac;
 
+    if(is_ac) huff_sym[0]= 16*256;
+
     return init_vlc_sparse(vlc, 9, nb_codes, huff_size, 1, 1, huff_code, 2, 2, huff_sym, 2, 2, use_static);
 }
 
@@ -69,6 +71,10 @@ static void build_basic_mjpeg_vlc(MJpegDecodeContext * s) {
               ff_mjpeg_val_ac_luminance, 251, 0, 1);
     build_vlc(&s->vlcs[1][1], ff_mjpeg_bits_ac_chrominance,
               ff_mjpeg_val_ac_chrominance, 251, 0, 1);
+    build_vlc(&s->vlcs[2][0], ff_mjpeg_bits_ac_luminance,
+              ff_mjpeg_val_ac_luminance, 251, 0, 0);
+    build_vlc(&s->vlcs[2][1], ff_mjpeg_bits_ac_chrominance,
+              ff_mjpeg_val_ac_chrominance, 251, 0, 0);
 }
 
 av_cold int ff_mjpeg_decode_init(AVCodecContext *avctx)
@@ -188,6 +194,13 @@ int ff_mjpeg_decode_dht(MJpegDecodeContext *s)
         if(build_vlc(&s->vlcs[class][index], bits_table, val_table, code_max + 1, 0, class > 0) < 0){
             return -1;
         }
+
+        if(class>0){
+            free_vlc(&s->vlcs[2][index]);
+            if(build_vlc(&s->vlcs[2][index], bits_table, val_table, code_max + 1, 0, 0) < 0){
+            return -1;
+            }
+        }
     }
     return 0;
 }
@@ -404,13 +417,10 @@ static int decode_block(MJpegDecodeContext *s, DCTELEM *block,
     /* AC coefs */
     i = 0;
     {OPEN_READER(re, &s->gb)
-    for(;;) {
+    do {
         UPDATE_CACHE(re, &s->gb);
         GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2)
 
-        /* EOB */
-        if (code == 0x10)
-            break;
         i += ((unsigned)code) >> 4;
             code &= 0xf;
         if(code){
@@ -425,19 +435,14 @@ static int decode_block(MJpegDecodeContext *s, DCTELEM *block,
 
             LAST_SKIP_BITS(re, &s->gb, code)
 
-            if (i >= 63) {
-                if(i == 63){
-                    j = s->scantable.permutated[63];
-                    block[j] = level * quant_matrix[j];
-                    break;
-                }
+            if (i > 63) {
                 av_log(s->avctx, AV_LOG_ERROR, "error count: %d\n", i);
                 return -1;
             }
             j = s->scantable.permutated[i];
             block[j] = level * quant_matrix[j];
         }
-    }
+    }while(i<63);
     CLOSE_READER(re, &s->gb)}
 
     return 0;
@@ -473,12 +478,12 @@ static int decode_block_progressive(MJpegDecodeContext *s, DCTELEM *block, uint8
     {OPEN_READER(re, &s->gb)
     for(i=ss;;i++) {
         UPDATE_CACHE(re, &s->gb);
-        GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2)
-        /* Progressive JPEG use AC coeffs from zero and this decoder sets offset 16 by default */
-        code -= 16;
-        if(code & 0xF) {
-            i += ((unsigned) code) >> 4;
-            code &= 0xf;
+        GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2)
+
+        run = ((unsigned) code) >> 4;
+        code &= 0xF;
+        if(code) {
+            i += run;
             if(code > MIN_CACHE_BITS - 16){
                 UPDATE_CACHE(re, &s->gb)
             }
@@ -502,17 +507,20 @@ static int decode_block_progressive(MJpegDecodeContext *s, DCTELEM *block, uint8
             j = s->scantable.permutated[i];
             block[j] = level * quant_matrix[j] << Al;
         }else{
-            run = ((unsigned) code) >> 4;
             if(run == 0xF){// ZRL - skip 15 coefficients
                 i += 15;
+                if (i >= se) {
+                    av_log(s->avctx, AV_LOG_ERROR, "ZRL overflow: %d\n", i);
+                    return -1;
+                }
             }else{
-                val = run;
-                run = (1 << run);
-                UPDATE_CACHE(re, &s->gb);
-                run += (GET_CACHE(re, &s->gb) >> (32 - val)) & (run - 1);
-                if(val)
-                    LAST_SKIP_BITS(re, &s->gb, val);
-                *EOBRUN = run - 1;
+                val = (1 << run);
+                if(run){
+                    UPDATE_CACHE(re, &s->gb);
+                    val += NEG_USR32(GET_CACHE(re, &s->gb), run);
+                    LAST_SKIP_BITS(re, &s->gb, run);
+                }
+                *EOBRUN = val - 1;
                 break;
             }
         }
@@ -561,9 +569,8 @@ static int decode_block_refinement(MJpegDecodeContext *s, DCTELEM *block, uint8_
     else {
         for(;;i++) {
             UPDATE_CACHE(re, &s->gb);
-            GET_VLC(code, re, &s->gb, s->vlcs[1][ac_index].table, 9, 2)
-            /* Progressive JPEG use AC coeffs from zero and this decoder sets offset 16 by default */
-            code -= 16;
+            GET_VLC(code, re, &s->gb, s->vlcs[2][ac_index].table, 9, 2)
+
             if(code & 0xF) {
                 run = ((unsigned) code) >> 4;
                 UPDATE_CACHE(re, &s->gb);
@@ -1518,7 +1525,7 @@ av_cold int ff_mjpeg_decode_end(AVCodecContext *avctx)
     av_freep(&s->ljpeg_buffer);
     s->ljpeg_buffer_size=0;
 
-    for(i=0;i<2;i++) {
+    for(i=0;i<3;i++) {
         for(j=0;j<4;j++)
             free_vlc(&s->vlcs[i][j]);
     }