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Diffstat (limited to 'thirdparty/libwebp/src/dec/vp8l_dec.c')
-rw-r--r--thirdparty/libwebp/src/dec/vp8l_dec.c103
1 files changed, 78 insertions, 25 deletions
diff --git a/thirdparty/libwebp/src/dec/vp8l_dec.c b/thirdparty/libwebp/src/dec/vp8l_dec.c
index 0570f53a77..333bb3e80d 100644
--- a/thirdparty/libwebp/src/dec/vp8l_dec.c
+++ b/thirdparty/libwebp/src/dec/vp8l_dec.c
@@ -362,12 +362,19 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
VP8LMetadata* const hdr = &dec->hdr_;
uint32_t* huffman_image = NULL;
HTreeGroup* htree_groups = NULL;
+ // When reading htrees, some might be unused, as the format allows it.
+ // We will still read them but put them in this htree_group_bogus.
+ HTreeGroup htree_group_bogus;
HuffmanCode* huffman_tables = NULL;
+ HuffmanCode* huffman_tables_bogus = NULL;
HuffmanCode* next = NULL;
int num_htree_groups = 1;
+ int num_htree_groups_max = 1;
int max_alphabet_size = 0;
int* code_lengths = NULL;
const int table_size = kTableSize[color_cache_bits];
+ int* mapping = NULL;
+ int ok = 0;
if (allow_recursion && VP8LReadBits(br, 1)) {
// use meta Huffman codes.
@@ -384,9 +391,41 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
// The huffman data is stored in red and green bytes.
const int group = (huffman_image[i] >> 8) & 0xffff;
huffman_image[i] = group;
- if (group >= num_htree_groups) {
- num_htree_groups = group + 1;
+ if (group >= num_htree_groups_max) {
+ num_htree_groups_max = group + 1;
+ }
+ }
+ // Check the validity of num_htree_groups_max. If it seems too big, use a
+ // smaller value for later. This will prevent big memory allocations to end
+ // up with a bad bitstream anyway.
+ // The value of 1000 is totally arbitrary. We know that num_htree_groups_max
+ // is smaller than (1 << 16) and should be smaller than the number of pixels
+ // (though the format allows it to be bigger).
+ if (num_htree_groups_max > 1000 || num_htree_groups_max > xsize * ysize) {
+ // Create a mapping from the used indices to the minimal set of used
+ // values [0, num_htree_groups)
+ mapping = (int*)WebPSafeMalloc(num_htree_groups_max, sizeof(*mapping));
+ if (mapping == NULL) {
+ dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
+ goto Error;
+ }
+ // -1 means a value is unmapped, and therefore unused in the Huffman
+ // image.
+ memset(mapping, 0xff, num_htree_groups_max * sizeof(*mapping));
+ for (num_htree_groups = 0, i = 0; i < huffman_pixs; ++i) {
+ // Get the current mapping for the group and remap the Huffman image.
+ int* const mapped_group = &mapping[huffman_image[i]];
+ if (*mapped_group == -1) *mapped_group = num_htree_groups++;
+ huffman_image[i] = *mapped_group;
+ }
+ huffman_tables_bogus = (HuffmanCode*)WebPSafeMalloc(
+ table_size, sizeof(*huffman_tables_bogus));
+ if (huffman_tables_bogus == NULL) {
+ dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
+ goto Error;
}
+ } else {
+ num_htree_groups = num_htree_groups_max;
}
}
@@ -403,11 +442,11 @@ 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);
- code_lengths = (int*)WebPSafeCalloc((uint64_t)max_alphabet_size,
- sizeof(*code_lengths));
if (htree_groups == NULL || code_lengths == NULL || huffman_tables == NULL) {
dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
@@ -415,28 +454,35 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
}
next = huffman_tables;
- for (i = 0; i < num_htree_groups; ++i) {
- HTreeGroup* const htree_group = &htree_groups[i];
+ for (i = 0; i < num_htree_groups_max; ++i) {
+ // If the index "i" is unused in the Huffman image, read the coefficients
+ // but store them to a bogus htree_group.
+ const int is_bogus = (mapping != NULL && mapping[i] == -1);
+ HTreeGroup* const htree_group =
+ is_bogus ? &htree_group_bogus :
+ &htree_groups[(mapping == NULL) ? i : mapping[i]];
HuffmanCode** const htrees = htree_group->htrees;
+ HuffmanCode* huffman_tables_i = is_bogus ? huffman_tables_bogus : next;
int size;
int total_size = 0;
int is_trivial_literal = 1;
int max_bits = 0;
for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
int alphabet_size = kAlphabetSize[j];
- htrees[j] = next;
+ htrees[j] = huffman_tables_i;
if (j == 0 && color_cache_bits > 0) {
alphabet_size += 1 << color_cache_bits;
}
- size = ReadHuffmanCode(alphabet_size, dec, code_lengths, next);
+ size =
+ ReadHuffmanCode(alphabet_size, dec, code_lengths, huffman_tables_i);
if (size == 0) {
goto Error;
}
if (is_trivial_literal && kLiteralMap[j] == 1) {
- is_trivial_literal = (next->bits == 0);
+ is_trivial_literal = (huffman_tables_i->bits == 0);
}
- total_size += next->bits;
- next += size;
+ total_size += huffman_tables_i->bits;
+ huffman_tables_i += size;
if (j <= ALPHA) {
int local_max_bits = code_lengths[0];
int k;
@@ -448,38 +494,41 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
max_bits += local_max_bits;
}
}
+ if (!is_bogus) next = huffman_tables_i;
htree_group->is_trivial_literal = is_trivial_literal;
htree_group->is_trivial_code = 0;
if (is_trivial_literal) {
const int red = htrees[RED][0].value;
const int blue = htrees[BLUE][0].value;
const int alpha = htrees[ALPHA][0].value;
- htree_group->literal_arb =
- ((uint32_t)alpha << 24) | (red << 16) | blue;
+ htree_group->literal_arb = ((uint32_t)alpha << 24) | (red << 16) | blue;
if (total_size == 0 && htrees[GREEN][0].value < NUM_LITERAL_CODES) {
htree_group->is_trivial_code = 1;
htree_group->literal_arb |= htrees[GREEN][0].value << 8;
}
}
- htree_group->use_packed_table = !htree_group->is_trivial_code &&
- (max_bits < HUFFMAN_PACKED_BITS);
+ htree_group->use_packed_table =
+ !htree_group->is_trivial_code && (max_bits < HUFFMAN_PACKED_BITS);
if (htree_group->use_packed_table) BuildPackedTable(htree_group);
}
- WebPSafeFree(code_lengths);
+ ok = 1;
- // All OK. Finalize pointers and return.
+ // All OK. Finalize pointers.
hdr->huffman_image_ = huffman_image;
hdr->num_htree_groups_ = num_htree_groups;
hdr->htree_groups_ = htree_groups;
hdr->huffman_tables_ = huffman_tables;
- return 1;
Error:
WebPSafeFree(code_lengths);
- WebPSafeFree(huffman_image);
- WebPSafeFree(huffman_tables);
- VP8LHtreeGroupsFree(htree_groups);
- return 0;
+ WebPSafeFree(huffman_tables_bogus);
+ WebPSafeFree(mapping);
+ if (!ok) {
+ WebPSafeFree(huffman_image);
+ WebPSafeFree(huffman_tables);
+ VP8LHtreeGroupsFree(htree_groups);
+ }
+ return ok;
}
//------------------------------------------------------------------------------
@@ -884,7 +933,11 @@ static WEBP_INLINE void CopyBlock8b(uint8_t* const dst, int dist, int length) {
#endif
break;
case 2:
+#if !defined(WORDS_BIGENDIAN)
memcpy(&pattern, src, sizeof(uint16_t));
+#else
+ pattern = ((uint32_t)src[0] << 8) | src[1];
+#endif
#if defined(__arm__) || defined(_M_ARM)
pattern |= pattern << 16;
#elif defined(WEBP_USE_MIPS_DSP_R2)
@@ -1523,7 +1576,6 @@ int VP8LDecodeAlphaHeader(ALPHDecoder* const alph_dec,
if (dec == NULL) return 0;
assert(alph_dec != NULL);
- alph_dec->vp8l_dec_ = dec;
dec->width_ = alph_dec->width_;
dec->height_ = alph_dec->height_;
@@ -1555,11 +1607,12 @@ int VP8LDecodeAlphaHeader(ALPHDecoder* const alph_dec,
if (!ok) goto Err;
+ // Only set here, once we are sure it is valid (to avoid thread races).
+ alph_dec->vp8l_dec_ = dec;
return 1;
Err:
- VP8LDelete(alph_dec->vp8l_dec_);
- alph_dec->vp8l_dec_ = NULL;
+ VP8LDelete(dec);
return 0;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-15 17:34:04 +0000