dvbsubdec: Fix function return type

[ffmpeg] / libavcodec / huffman.c

diff --git a/libavcodec/huffman.c b/libavcodec/huffman.c
index 676fffe0f591c2e6018d76586bb130c305f50779..f13ab296a5ddb97cdc81f5b2865007e0831b0302 100644 (file)
--- a/libavcodec/huffman.c
+++ b/libavcodec/huffman.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (c) 2006 Konstantin Shishkov
+ * Copyright (c) 2007 Loren Merritt
  *
  * This file is part of Libav.
  *
@@ -23,6 +24,8 @@
  * huffman tree builder and VLC generator
  */
 
+#include <stdint.h>
+
 #include "avcodec.h"
 #include "get_bits.h"
 #include "huffman.h"
@@ -30,6 +33,63 @@
 /* symbol for Huffman tree node */
 #define HNODE -1
 
+typedef struct HeapElem {
+    uint64_t val;
+    int name;
+} HeapElem;
+
+static void heap_sift(HeapElem *h, int root, int size)
+{
+    while (root * 2 + 1 < size) {
+        int child = root * 2 + 1;
+        if (child < size - 1 && h[child].val > h[child+1].val)
+            child++;
+        if (h[root].val > h[child].val) {
+            FFSWAP(HeapElem, h[root], h[child]);
+            root = child;
+        } else
+            break;
+    }
+}
+
+void ff_huff_gen_len_table(uint8_t *dst, const uint64_t *stats)
+{
+    HeapElem h[256];
+    int up[2*256];
+    int len[2*256];
+    int offset, i, next;
+    int size = 256;
+
+    for (offset = 1; ; offset <<= 1) {
+        for (i=0; i < size; i++) {
+            h[i].name = i;
+            h[i].val = (stats[i] << 8) + offset;
+        }
+        for (i = size / 2 - 1; i >= 0; i--)
+            heap_sift(h, i, size);
+
+        for (next = size; next < size * 2 - 1; next++) {
+            // merge the two smallest entries, and put it back in the heap
+            uint64_t min1v = h[0].val;
+            up[h[0].name] = next;
+            h[0].val = INT64_MAX;
+            heap_sift(h, 0, size);
+            up[h[0].name] = next;
+            h[0].name = next;
+            h[0].val += min1v;
+            heap_sift(h, 0, size);
+        }
+
+        len[2 * size - 2] = 0;
+        for (i = 2 * size - 3; i >= size; i--)
+            len[i] = len[up[i]] + 1;
+        for (i = 0; i < size; i++) {
+            dst[i] = len[up[i]] + 1;
+            if (dst[i] >= 32) break;
+        }
+        if (i==size) break;
+    }
+}
 
 static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat,
                            Node *nodes, int node,
@@ -54,7 +114,7 @@ static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat,
     }
 }
 
-static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags)
+static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags, int nb_bits)
 {
     int no_zero_count = !(flags & FF_HUFFMAN_FLAG_ZERO_COUNT);
     uint32_t bits[256];
@@ -64,7 +124,7 @@ static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags)
 
     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);
+    return ff_init_vlc_sparse(vlc, nb_bits, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
 }
 
 
@@ -72,7 +132,7 @@ static int build_huff_tree(VLC *vlc, Node *nodes, int head, int flags)
  * 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,
+int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes, int nb_bits,
                        Node *nodes, HuffCmp cmp, int flags)
 {
     int i, j;
@@ -109,7 +169,7 @@ int ff_huff_build_tree(AVCodecContext *avctx, VLC *vlc, int nb_codes,
         }
         cur_node++;
     }
-    if (build_huff_tree(vlc, nodes, nb_codes * 2 - 2, flags) < 0) {
+    if (build_huff_tree(vlc, nodes, nb_codes * 2 - 2, flags, nb_bits) < 0) {
         av_log(avctx, AV_LOG_ERROR, "Error building tree\n");
         return -1;
     }