celp filters: Do not read earlier than the start of the 'out' vector.

[ffmpeg] / libavcodec / huffman.c

diff --git a/libavcodec/huffman.c b/libavcodec/huffman.c
index 298dc153970e0120b38f63c87a2c6e8d5a78a9e7..9446332b7d9e59d5e8116cbb9044607be0fbbbb4 100644 (file)
--- a/libavcodec/huffman.c
+++ b/libavcodec/huffman.c
@@ -1,39 +1,42 @@
-/**
- * @file huffman.c
- * huffman tree builder and VLC generator
+/*
  * Copyright (c) 2006 Konstantin Shishkov
  *
- * 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
  */
 
+/**
+ * @file
+ * huffman tree builder and VLC generator
+ */
+
 #include "avcodec.h"
-#include "bitstream.h"
+#include "get_bits.h"
 #include "huffman.h"
 
 /* symbol for Huffman tree node */
 #define HNODE -1
 
 
-static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *nodes, int node, uint32_t pfx, int pl, int *pos)
+static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *nodes, int node, uint32_t pfx, int pl, int *pos, int no_zero_count)
 {
     int s;
 
     s = nodes[node].sym;
-    if(s != HNODE || !nodes[node].count){
+    if(s != HNODE || (no_zero_count && !nodes[node].count)){
         bits[*pos] = pfx;
         lens[*pos] = pl;
         xlat[*pos] = s;
@@ -41,29 +44,33 @@ static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat, Node *n
     }else{
         pfx <<= 1;
         pl++;
-        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl, pos);
+        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0, pfx, pl, pos,
+                       no_zero_count);
         pfx |= 1;
-        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0+1, pfx, pl, pos);
+        get_tree_codes(bits, lens, xlat, nodes, nodes[node].n0+1, pfx, pl, pos,
+                       no_zero_count);
     }
 }
 
-static int build_huff_tree(VLC *vlc, Node *nodes, int head)
+static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags)
 {
+    int no_zero_count = !(flags & FF_HUFFMAN_FLAG_ZERO_COUNT);
     uint32_t bits[256];
     int16_t lens[256];
     uint8_t xlat[256];
     int pos = 0;
 
-    get_tree_codes(bits, lens, xlat, nodes, head, 0, 0, &pos);
-    return init_vlc_sparse(vlc, 9, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
+    get_tree_codes(bits, lens, xlat, nodes, head, 0, 0, &pos, no_zero_count);
+    return ff_init_vlc_sparse(vlc, 9, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
 }
 
 
 /**
+ * nodes size must be 2*nb_codes
  * first nb_codes nodes.count must be set
  */
 int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
-                       Node nodes[2*nb_codes], huff_cmp_t cmp, int hnode_first)
+                       Node *nodes, HuffCmp cmp, int flags)
 {
     int i, j;
     int cur_node;
@@ -81,6 +88,7 @@ int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
     }
     qsort(nodes, nb_codes, sizeof(Node), cmp);
     cur_node = nb_codes;
+    nodes[nb_codes*2-1].count = 0;
     for(i = 0; i < nb_codes*2-1; i += 2){
         nodes[cur_node].sym = HNODE;
         nodes[cur_node].count = nodes[i].count + nodes[i+1].count;
@@ -88,14 +96,15 @@ int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
         for(j = cur_node; j > 0; j--){
             if(nodes[j].count > nodes[j-1].count ||
                (nodes[j].count == nodes[j-1].count &&
-                (!hnode_first || nodes[j].n0==j-1 || nodes[j].n0==j-2 ||
+                (!(flags & FF_HUFFMAN_FLAG_HNODE_FIRST) ||
+                 nodes[j].n0==j-1 || nodes[j].n0==j-2 ||
                  (nodes[j].sym!=HNODE && nodes[j-1].sym!=HNODE))))
                 break;
             FFSWAP(Node, nodes[j], nodes[j-1]);
         }
         cur_node++;
     }
-    if(build_huff_tree(vlc, nodes, nb_codes*2-2) < 0){
+    if(build_huff_tree(vlc, nodes, nb_codes*2-2, flags) < 0){
         av_log(avctx, AV_LOG_ERROR, "Error building tree\n");
         return -1;
     }