update ChangeLog

Bug: webp:620
Change-Id: I5703f222de7262736339dbfd6ba82f2039dfc850

ChangeLog

@@ -1,3 +1,7 @@
+1ace578c update NEWS
+63234c42 bump version to 1.3.2
+2af26267 Fix OOB write in BuildHuffmanTable.
+fd7bb21c update ChangeLog (tag: v1.3.1-rc2, tag: v1.3.1)
 e1adea50 update NEWS
 43393320 enc/*: normalize WebPEncodingSetError() calls
 287fdefe enc/*: add missing WebPEncodingSetError() calls

NEWS

@@ -1,3 +1,7 @@
+- 9/13/2023: version 1.3.2
+  This is a binary compatible release.
+  * security fix for lossless decoder (chromium: #1479274, CVE-2023-4863)
+
 - 6/23/2023: version 1.3.1
   This is a binary compatible release.
   * security fixes for lossless encoder (#603, chromium: #1420107, #1455619,

README.md

@@ -7,7 +7,7 @@
       \__\__/\____/\_____/__/ ____  ___
             / _/ /    \    \ /  _ \/ _/
            /  \_/   / /   \ \   __/  \__
-           \____/____/\_____/_____/____/v1.3.1
+           \____/____/\_____/_____/____/v1.3.2
 ```
 
 WebP codec is a library to encode and decode images in WebP format. This package

configure.ac

@@ -1,4 +1,4 @@
-AC_INIT([libwebp], [1.3.1],
+AC_INIT([libwebp], [1.3.2],
         [https://bugs.chromium.org/p/webp],,
         [https://developers.google.com/speed/webp])
 AC_CANONICAL_HOST

extras/extras.c

@@ -19,7 +19,7 @@
 
 #define XTRA_MAJ_VERSION 1
 #define XTRA_MIN_VERSION 3
-#define XTRA_REV_VERSION 1
+#define XTRA_REV_VERSION 2
 
 //------------------------------------------------------------------------------
 

src/Makefile.am

@@ -36,7 +36,7 @@ libwebp_la_LIBADD += utils/libwebputils.la
 # other than the ones listed on the command line, i.e., after linking, it will
 # not have unresolved symbols. Some platforms (Windows among them) require all
 # symbols in shared libraries to be resolved at library creation.
-libwebp_la_LDFLAGS = -no-undefined -version-info 8:7:1
+libwebp_la_LDFLAGS = -no-undefined -version-info 8:8:1
 libwebpincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebp.pc
 
@@ -48,7 +48,7 @@ if BUILD_LIBWEBPDECODER
   libwebpdecoder_la_LIBADD += dsp/libwebpdspdecode.la
   libwebpdecoder_la_LIBADD += utils/libwebputilsdecode.la
 
-  libwebpdecoder_la_LDFLAGS = -no-undefined -version-info 4:7:1
+  libwebpdecoder_la_LDFLAGS = -no-undefined -version-info 4:8:1
   pkgconfig_DATA += libwebpdecoder.pc
 endif
 

src/dec/vp8i_dec.h

@@ -32,7 +32,7 @@ extern "C" {
 // version numbers
 #define DEC_MAJ_VERSION 1
 #define DEC_MIN_VERSION 3
-#define DEC_REV_VERSION 1
+#define DEC_REV_VERSION 2
 
 // YUV-cache parameters. Cache is 32-bytes wide (= one cacheline).
 // Constraints are: We need to store one 16x16 block of luma samples (y),

src/dec/vp8l_dec.c

@@ -253,11 +253,11 @@ static int ReadHuffmanCodeLengths(
   int symbol;
   int max_symbol;
   int prev_code_len = DEFAULT_CODE_LENGTH;
-  HuffmanCode table[1 << LENGTHS_TABLE_BITS];
+  HuffmanTables tables;
 
-  if (!VP8LBuildHuffmanTable(table, LENGTHS_TABLE_BITS,
-                             code_length_code_lengths,
-                             NUM_CODE_LENGTH_CODES)) {
+  if (!VP8LHuffmanTablesAllocate(1 << LENGTHS_TABLE_BITS, &tables) ||
+      !VP8LBuildHuffmanTable(&tables, LENGTHS_TABLE_BITS,
+                             code_length_code_lengths, NUM_CODE_LENGTH_CODES)) {
     goto End;
   }
 
@@ -277,7 +277,7 @@ static int ReadHuffmanCodeLengths(
     int code_len;
     if (max_symbol-- == 0) break;
     VP8LFillBitWindow(br);
-    p = &table[VP8LPrefetchBits(br) & LENGTHS_TABLE_MASK];
+    p = &tables.curr_segment->start[VP8LPrefetchBits(br) & LENGTHS_TABLE_MASK];
     VP8LSetBitPos(br, br->bit_pos_ + p->bits);
     code_len = p->value;
     if (code_len < kCodeLengthLiterals) {
@@ -300,6 +300,7 @@ static int ReadHuffmanCodeLengths(
   ok = 1;
 
  End:
+  VP8LHuffmanTablesDeallocate(&tables);
   if (!ok) dec->status_ = VP8_STATUS_BITSTREAM_ERROR;
   return ok;
 }
@@ -307,7 +308,8 @@ static int ReadHuffmanCodeLengths(
 // 'code_lengths' is pre-allocated temporary buffer, used for creating Huffman
 // tree.
 static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
-                           int* const code_lengths, HuffmanCode* const table) {
+                           int* const code_lengths,
+                           HuffmanTables* const table) {
   int ok = 0;
   int size = 0;
   VP8LBitReader* const br = &dec->br_;
@@ -362,8 +364,7 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
   VP8LMetadata* const hdr = &dec->hdr_;
   uint32_t* huffman_image = NULL;
   HTreeGroup* htree_groups = NULL;
-  HuffmanCode* huffman_tables = NULL;
-  HuffmanCode* huffman_table = NULL;
+  HuffmanTables* huffman_tables = &hdr->huffman_tables_;
   int num_htree_groups = 1;
   int num_htree_groups_max = 1;
   int max_alphabet_size = 0;
@@ -372,6 +373,10 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
   int* mapping = NULL;
   int ok = 0;
 
+  // Check the table has been 0 initialized (through InitMetadata).
+  assert(huffman_tables->root.start == NULL);
+  assert(huffman_tables->curr_segment == NULL);
+
   if (allow_recursion && VP8LReadBits(br, 1)) {
     // use meta Huffman codes.
     const int huffman_precision = VP8LReadBits(br, 3) + 2;
@@ -434,16 +439,15 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
 
   code_lengths = (int*)WebPSafeCalloc((uint64_t)max_alphabet_size,
                                       sizeof(*code_lengths));
-  huffman_tables = (HuffmanCode*)WebPSafeMalloc(num_htree_groups * table_size,
-                                                sizeof(*huffman_tables));
   htree_groups = VP8LHtreeGroupsNew(num_htree_groups);
 
-  if (htree_groups == NULL || code_lengths == NULL || huffman_tables == NULL) {
+  if (htree_groups == NULL || code_lengths == NULL ||
+      !VP8LHuffmanTablesAllocate(num_htree_groups * table_size,
+                                 huffman_tables)) {
     dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
     goto Error;
   }
 
-  huffman_table = huffman_tables;
   for (i = 0; i < num_htree_groups_max; ++i) {
     // If the index "i" is unused in the Huffman image, just make sure the
     // coefficients are valid but do not store them.
@@ -468,19 +472,20 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
       int max_bits = 0;
       for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
         int alphabet_size = kAlphabetSize[j];
-        htrees[j] = huffman_table;
         if (j == 0 && color_cache_bits > 0) {
           alphabet_size += (1 << color_cache_bits);
         }
-        size = ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_table);
+        size =
+            ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_tables);
+        htrees[j] = huffman_tables->curr_segment->curr_table;
         if (size == 0) {
           goto Error;
         }
         if (is_trivial_literal && kLiteralMap[j] == 1) {
-          is_trivial_literal = (huffman_table->bits == 0);
+          is_trivial_literal = (htrees[j]->bits == 0);
         }
-        total_size += huffman_table->bits;
-        huffman_table += size;
+        total_size += htrees[j]->bits;
+        huffman_tables->curr_segment->curr_table += size;
         if (j <= ALPHA) {
           int local_max_bits = code_lengths[0];
           int k;
@@ -515,14 +520,13 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
   hdr->huffman_image_ = huffman_image;
   hdr->num_htree_groups_ = num_htree_groups;
   hdr->htree_groups_ = htree_groups;
-  hdr->huffman_tables_ = huffman_tables;
 
  Error:
   WebPSafeFree(code_lengths);
   WebPSafeFree(mapping);
   if (!ok) {
     WebPSafeFree(huffman_image);
-    WebPSafeFree(huffman_tables);
+    VP8LHuffmanTablesDeallocate(huffman_tables);
     VP8LHtreeGroupsFree(htree_groups);
   }
   return ok;
@@ -1358,7 +1362,7 @@ static void ClearMetadata(VP8LMetadata* const hdr) {
   assert(hdr != NULL);
 
   WebPSafeFree(hdr->huffman_image_);
-  WebPSafeFree(hdr->huffman_tables_);
+  VP8LHuffmanTablesDeallocate(&hdr->huffman_tables_);
   VP8LHtreeGroupsFree(hdr->htree_groups_);
   VP8LColorCacheClear(&hdr->color_cache_);
   VP8LColorCacheClear(&hdr->saved_color_cache_);
@@ -1673,7 +1677,7 @@ int VP8LDecodeImage(VP8LDecoder* const dec) {
 
   if (dec == NULL) return 0;
 
-  assert(dec->hdr_.huffman_tables_ != NULL);
+  assert(dec->hdr_.huffman_tables_.root.start != NULL);
   assert(dec->hdr_.htree_groups_ != NULL);
   assert(dec->hdr_.num_htree_groups_ > 0);
 

src/dec/vp8li_dec.h

@@ -51,7 +51,7 @@ typedef struct {
   uint32_t*       huffman_image_;
   int             num_htree_groups_;
   HTreeGroup*     htree_groups_;
-  HuffmanCode*    huffman_tables_;
+  HuffmanTables   huffman_tables_;
 } VP8LMetadata;
 
 typedef struct VP8LDecoder VP8LDecoder;

src/demux/Makefile.am

@@ -13,6 +13,6 @@ noinst_HEADERS =
 noinst_HEADERS += ../webp/format_constants.h
 
 libwebpdemux_la_LIBADD = ../libwebp.la
-libwebpdemux_la_LDFLAGS = -no-undefined -version-info 2:13:0
+libwebpdemux_la_LDFLAGS = -no-undefined -version-info 2:14:0
 libwebpdemuxincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebpdemux.pc

src/demux/demux.c

@@ -25,7 +25,7 @@
 
 #define DMUX_MAJ_VERSION 1
 #define DMUX_MIN_VERSION 3
-#define DMUX_REV_VERSION 1
+#define DMUX_REV_VERSION 2
 
 typedef struct {
   size_t start_;        // start location of the data

src/demux/libwebpdemux.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,1
+ FILEVERSION 1,0,3,2
+ PRODUCTVERSION 1,0,3,2
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpdemux DLL"
-            VALUE "FileVersion", "1.3.1"
+            VALUE "FileVersion", "1.3.2"
             VALUE "InternalName", "libwebpdemux.dll"
             VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpdemux.dll"
             VALUE "ProductName", "WebP Image Demuxer"
-            VALUE "ProductVersion", "1.3.1"
+            VALUE "ProductVersion", "1.3.2"
         END
     END
     BLOCK "VarFileInfo"

src/enc/vp8i_enc.h

@@ -32,7 +32,7 @@ extern "C" {
 // version numbers
 #define ENC_MAJ_VERSION 1
 #define ENC_MIN_VERSION 3
-#define ENC_REV_VERSION 1
+#define ENC_REV_VERSION 2
 
 enum { MAX_LF_LEVELS = 64,       // Maximum loop filter level
        MAX_VARIABLE_LEVEL = 67,  // last (inclusive) level with variable cost

src/libwebp.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,1
+ FILEVERSION 1,0,3,2
+ PRODUCTVERSION 1,0,3,2
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebp DLL"
-            VALUE "FileVersion", "1.3.1"
+            VALUE "FileVersion", "1.3.2"
             VALUE "InternalName", "libwebp.dll"
             VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebp.dll"
             VALUE "ProductName", "WebP Image Codec"
-            VALUE "ProductVersion", "1.3.1"
+            VALUE "ProductVersion", "1.3.2"
         END
     END
     BLOCK "VarFileInfo"

src/libwebpdecoder.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,1
+ FILEVERSION 1,0,3,2
+ PRODUCTVERSION 1,0,3,2
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpdecoder DLL"
-            VALUE "FileVersion", "1.3.1"
+            VALUE "FileVersion", "1.3.2"
             VALUE "InternalName", "libwebpdecoder.dll"
             VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpdecoder.dll"
             VALUE "ProductName", "WebP Image Decoder"
-            VALUE "ProductVersion", "1.3.1"
+            VALUE "ProductVersion", "1.3.2"
         END
     END
     BLOCK "VarFileInfo"

src/mux/Makefile.am

@@ -17,6 +17,6 @@ noinst_HEADERS =
 noinst_HEADERS += ../webp/format_constants.h
 
 libwebpmux_la_LIBADD = ../libwebp.la
-libwebpmux_la_LDFLAGS = -no-undefined -version-info 3:12:0 -lm
+libwebpmux_la_LDFLAGS = -no-undefined -version-info 3:13:0 -lm
 libwebpmuxincludedir = $(includedir)/webp
 pkgconfig_DATA = libwebpmux.pc

src/mux/libwebpmux.rc

@@ -6,8 +6,8 @@
 LANGUAGE LANG_ENGLISH, SUBLANG_ENGLISH_US
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 1,0,3,1
- PRODUCTVERSION 1,0,3,1
+ FILEVERSION 1,0,3,2
+ PRODUCTVERSION 1,0,3,2
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -24,12 +24,12 @@ BEGIN
         BEGIN
             VALUE "CompanyName", "Google, Inc."
             VALUE "FileDescription", "libwebpmux DLL"
-            VALUE "FileVersion", "1.3.1"
+            VALUE "FileVersion", "1.3.2"
             VALUE "InternalName", "libwebpmux.dll"
             VALUE "LegalCopyright", "Copyright (C) 2023"
             VALUE "OriginalFilename", "libwebpmux.dll"
             VALUE "ProductName", "WebP Image Muxer"
-            VALUE "ProductVersion", "1.3.1"
+            VALUE "ProductVersion", "1.3.2"
         END
     END
     BLOCK "VarFileInfo"

src/mux/muxi.h

@@ -29,7 +29,7 @@ extern "C" {
 
 #define MUX_MAJ_VERSION 1
 #define MUX_MIN_VERSION 3
-#define MUX_REV_VERSION 1
+#define MUX_REV_VERSION 2
 
 // Chunk object.
 typedef struct WebPChunk WebPChunk;

src/utils/huffman_utils.c

@@ -177,21 +177,24 @@ static int BuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
       if (num_open < 0) {
         return 0;
       }
-      if (root_table == NULL) continue;
       for (; count[len] > 0; --count[len]) {
         HuffmanCode code;
         if ((key & mask) != low) {
-          table += table_size;
+          if (root_table != NULL) table += table_size;
           table_bits = NextTableBitSize(count, len, root_bits);
           table_size = 1 << table_bits;
           total_size += table_size;
           low = key & mask;
-          root_table[low].bits = (uint8_t)(table_bits + root_bits);
-          root_table[low].value = (uint16_t)((table - root_table) - low);
+          if (root_table != NULL) {
+            root_table[low].bits = (uint8_t)(table_bits + root_bits);
+            root_table[low].value = (uint16_t)((table - root_table) - low);
+          }
+        }
+        if (root_table != NULL) {
+          code.bits = (uint8_t)(len - root_bits);
+          code.value = (uint16_t)sorted[symbol++];
+          ReplicateValue(&table[key >> root_bits], step, table_size, code);
         }
-        code.bits = (uint8_t)(len - root_bits);
-        code.value = (uint16_t)sorted[symbol++];
-        ReplicateValue(&table[key >> root_bits], step, table_size, code);
         key = GetNextKey(key, len);
       }
     }
@@ -211,25 +214,83 @@ static int BuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
   ((1 << MAX_CACHE_BITS) + NUM_LITERAL_CODES + NUM_LENGTH_CODES)
 // Cut-off value for switching between heap and stack allocation.
 #define SORTED_SIZE_CUTOFF 512
-int VP8LBuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
+int VP8LBuildHuffmanTable(HuffmanTables* const root_table, int root_bits,
                           const int code_lengths[], int code_lengths_size) {
-  int total_size;
+  const int total_size =
+      BuildHuffmanTable(NULL, root_bits, code_lengths, code_lengths_size, NULL);
   assert(code_lengths_size <= MAX_CODE_LENGTHS_SIZE);
-  if (root_table == NULL) {
-    total_size = BuildHuffmanTable(NULL, root_bits,
-                                   code_lengths, code_lengths_size, NULL);
-  } else if (code_lengths_size <= SORTED_SIZE_CUTOFF) {
+  if (total_size == 0 || root_table == NULL) return total_size;
+
+  if (root_table->curr_segment->curr_table + total_size >=
+      root_table->curr_segment->start + root_table->curr_segment->size) {
+    // If 'root_table' does not have enough memory, allocate a new segment.
+    // The available part of root_table->curr_segment is left unused because we
+    // need a contiguous buffer.
+    const int segment_size = root_table->curr_segment->size;
+    struct HuffmanTablesSegment* next =
+        (HuffmanTablesSegment*)WebPSafeMalloc(1, sizeof(*next));
+    if (next == NULL) return 0;
+    // Fill the new segment.
+    // We need at least 'total_size' but if that value is small, it is better to
+    // allocate a big chunk to prevent more allocations later. 'segment_size' is
+    // therefore chosen (any other arbitrary value could be chosen).
+    next->size = total_size > segment_size ? total_size : segment_size;
+    next->start =
+        (HuffmanCode*)WebPSafeMalloc(next->size, sizeof(*next->start));
+    if (next->start == NULL) {
+      WebPSafeFree(next);
+      return 0;
+    }
+    next->curr_table = next->start;
+    next->next = NULL;
+    // Point to the new segment.
+    root_table->curr_segment->next = next;
+    root_table->curr_segment = next;
+  }
+  if (code_lengths_size <= SORTED_SIZE_CUTOFF) {
     // use local stack-allocated array.
     uint16_t sorted[SORTED_SIZE_CUTOFF];
-    total_size = BuildHuffmanTable(root_table, root_bits,
-                                   code_lengths, code_lengths_size, sorted);
-  } else {   // rare case. Use heap allocation.
+    BuildHuffmanTable(root_table->curr_segment->curr_table, root_bits,
+                      code_lengths, code_lengths_size, sorted);
+  } else {  // rare case. Use heap allocation.
     uint16_t* const sorted =
         (uint16_t*)WebPSafeMalloc(code_lengths_size, sizeof(*sorted));
     if (sorted == NULL) return 0;
-    total_size = BuildHuffmanTable(root_table, root_bits,
-                                   code_lengths, code_lengths_size, sorted);
+    BuildHuffmanTable(root_table->curr_segment->curr_table, root_bits,
+                      code_lengths, code_lengths_size, sorted);
     WebPSafeFree(sorted);
   }
   return total_size;
 }
+
+int VP8LHuffmanTablesAllocate(int size, HuffmanTables* huffman_tables) {
+  // Have 'segment' point to the first segment for now, 'root'.
+  HuffmanTablesSegment* const root = &huffman_tables->root;
+  huffman_tables->curr_segment = root;
+  // Allocate root.
+  root->start = (HuffmanCode*)WebPSafeMalloc(size, sizeof(*root->start));
+  if (root->start == NULL) return 0;
+  root->curr_table = root->start;
+  root->next = NULL;
+  root->size = size;
+  return 1;
+}
+
+void VP8LHuffmanTablesDeallocate(HuffmanTables* const huffman_tables) {
+  HuffmanTablesSegment *current, *next;
+  if (huffman_tables == NULL) return;
+  // Free the root node.
+  current = &huffman_tables->root;
+  next = current->next;
+  WebPSafeFree(current->start);
+  current->start = NULL;
+  current->next = NULL;
+  current = next;
+  // Free the following nodes.
+  while (current != NULL) {
+    next = current->next;
+    WebPSafeFree(current->start);
+    WebPSafeFree(current);
+    current = next;
+  }
+}

src/utils/huffman_utils.h

@@ -43,6 +43,29 @@ typedef struct {
                     // or non-literal symbol otherwise
 } HuffmanCode32;
 
+// Contiguous memory segment of HuffmanCodes.
+typedef struct HuffmanTablesSegment {
+  HuffmanCode* start;
+  // Pointer to where we are writing into the segment. Starts at 'start' and
+  // cannot go beyond 'start' + 'size'.
+  HuffmanCode* curr_table;
+  // Pointer to the next segment in the chain.
+  struct HuffmanTablesSegment* next;
+  int size;
+} HuffmanTablesSegment;
+
+// Chained memory segments of HuffmanCodes.
+typedef struct HuffmanTables {
+  HuffmanTablesSegment root;
+  // Currently processed segment. At first, this is 'root'.
+  HuffmanTablesSegment* curr_segment;
+} HuffmanTables;
+
+// Allocates a HuffmanTables with 'size' contiguous HuffmanCodes. Returns 0 on
+// memory allocation error, 1 otherwise.
+int VP8LHuffmanTablesAllocate(int size, HuffmanTables* huffman_tables);
+void VP8LHuffmanTablesDeallocate(HuffmanTables* const huffman_tables);
+
 #define HUFFMAN_PACKED_BITS 6
 #define HUFFMAN_PACKED_TABLE_SIZE (1u << HUFFMAN_PACKED_BITS)
 
@@ -78,9 +101,7 @@ void VP8LHtreeGroupsFree(HTreeGroup* const htree_groups);
 // the huffman table.
 // Returns built table size or 0 in case of error (invalid tree or
 // memory error).
-// If root_table is NULL, it returns 0 if a lookup cannot be built, something
-// > 0 otherwise (but not the table size).
-int VP8LBuildHuffmanTable(HuffmanCode* const root_table, int root_bits,
+int VP8LBuildHuffmanTable(HuffmanTables* const root_table, int root_bits,
                           const int code_lengths[], int code_lengths_size);
 
 #ifdef __cplusplus