change a variable-length array to a malloc.

Originally committed as revision 23103 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/bitstream.c

@@ -275,8 +275,8 @@ int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
              const void *symbols, int symbols_wrap, int symbols_size,
              int flags)
 {
-    VLCcode buf[nb_codes];
-    int i, j;
+    VLCcode *buf;
+    int i, j, ret;
 
     vlc->bits = nb_bits;
     if(flags & INIT_VLC_USE_NEW_STATIC){
@@ -295,6 +295,8 @@ int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
     av_log(NULL,AV_LOG_DEBUG,"build table nb_codes=%d\n", nb_codes);
 #endif
 
+    buf = av_malloc((nb_codes+1)*sizeof(VLCcode));
+
     assert(symbols_size <= 2 || !symbols);
     j = 0;
 #define COPY(condition)\
@@ -319,7 +321,10 @@ int init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes,
     COPY(buf[j].bits && buf[j].bits <= nb_bits);
     nb_codes = j;
 
-    if (build_table(vlc, nb_bits, nb_codes, buf, flags) < 0) {
+    ret = build_table(vlc, nb_bits, nb_codes, buf, flags);
+
+    av_free(buf);
+    if (ret < 0) {
         av_freep(&vlc->table);
         return -1;
     }