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Reduce number of memory allocations while decoding lossless.

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This change reduces the number of calls to WebPSafeMalloc from 200 to
100. The overall memory consumption is down 3% for Lenna image.

Change-Id: I1b351a1f61abf2634c035ef1ccb34050b7876bdd
This commit is contained in:
Vikas Arora
2014-04-30 21:41:32 +00:00
committed by James Zern
parent 888e63edc9
commit 9383afd5c7
4 changed files with 133 additions and 86 deletions
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82
src/dec/vp8l.c
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@ -187,9 +187,10 @@ static int ReadHuffmanCodeLengths(
int max_symbol;
int prev_code_len = DEFAULT_CODE_LENGTH;
HuffmanTree tree;
int huff_codes[NUM_CODE_LENGTH_CODES] = { 0 };
if (!HuffmanTreeBuildImplicit(&tree, code_length_code_lengths,
NUM_CODE_LENGTH_CODES)) {
if (!VP8LHuffmanTreeBuildImplicit(&tree, code_length_code_lengths,
huff_codes, NUM_CODE_LENGTH_CODES)) {
dec->status_ = VP8_STATUS_BITSTREAM_ERROR;
return 0;
}
@ -232,11 +233,14 @@ static int ReadHuffmanCodeLengths(
ok = 1;
End:
HuffmanTreeRelease(&tree);
VP8LHuffmanTreeFree(&tree);
return ok;
}
// '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, int* const huff_codes,
HuffmanTree* const tree) {
int ok = 0;
VP8LBitReader* const br = &dec->br_;
@ -245,7 +249,6 @@ static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
if (simple_code) { // Read symbols, codes & code lengths directly.
int symbols[2];
int codes[2];
int code_lengths[2];
const int num_symbols = VP8LReadBits(br, 1) + 1;
const int first_symbol_len_code = VP8LReadBits(br, 1);
// The first code is either 1 bit or 8 bit code.
@ -258,10 +261,9 @@ static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
codes[1] = 1;
code_lengths[1] = num_symbols - 1;
}
ok = HuffmanTreeBuildExplicit(tree, code_lengths, codes, symbols,
alphabet_size, num_symbols);
ok = VP8LHuffmanTreeBuildExplicit(tree, code_lengths, codes, symbols,
alphabet_size, num_symbols);
} else { // Decode Huffman-coded code lengths.
int* code_lengths = NULL;
int i;
int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
const int num_codes = VP8LReadBits(br, 4) + 4;
@ -270,22 +272,15 @@ static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
return 0;
}
code_lengths =
(int*)WebPSafeCalloc((uint64_t)alphabet_size, sizeof(*code_lengths));
if (code_lengths == NULL) {
dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
return 0;
}
memset(code_lengths, 0, alphabet_size * sizeof(*code_lengths));
for (i = 0; i < num_codes; ++i) {
code_length_code_lengths[kCodeLengthCodeOrder[i]] = VP8LReadBits(br, 3);
}
ok = ReadHuffmanCodeLengths(dec, code_length_code_lengths, alphabet_size,
code_lengths);
if (ok) {
ok = HuffmanTreeBuildImplicit(tree, code_lengths, alphabet_size);
}
WebPSafeFree(code_lengths);
ok = ok && VP8LHuffmanTreeBuildImplicit(tree, code_lengths, huff_codes,
alphabet_size);
}
ok = ok && !br->error_;
if (!ok) {
@ -295,19 +290,6 @@ static int ReadHuffmanCode(int alphabet_size, VP8LDecoder* const dec,
return 1;
}
static void DeleteHtreeGroups(HTreeGroup* htree_groups, int num_htree_groups) {
if (htree_groups != NULL) {
int i, j;
for (i = 0; i < num_htree_groups; ++i) {
HuffmanTree* const htrees = htree_groups[i].htrees_;
for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
HuffmanTreeRelease(&htrees[j]);
}
}
WebPSafeFree(htree_groups);
}
}
static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
int color_cache_bits, int allow_recursion) {
int i, j;
@ -316,6 +298,9 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
uint32_t* huffman_image = NULL;
HTreeGroup* htree_groups = NULL;
int num_htree_groups = 1;
int max_alphabet_size = 0;
int* code_lengths = NULL;
int* huff_codes = NULL;
if (allow_recursion && VP8LReadBits(br, 1)) {
// use meta Huffman codes.
@ -341,11 +326,24 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
if (br->error_) goto Error;
assert(num_htree_groups <= 0x10000);
htree_groups =
(HTreeGroup*)WebPSafeCalloc((uint64_t)num_htree_groups,
sizeof(*htree_groups));
if (htree_groups == NULL) {
// Find maximum alphabet size for the htree group.
for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
int alphabet_size = kAlphabetSize[j];
if (j == 0 && color_cache_bits > 0) {
alphabet_size += 1 << color_cache_bits;
}
if (max_alphabet_size < alphabet_size) {
max_alphabet_size = alphabet_size;
}
}
htree_groups = VP8LHtreeGroupsNew(num_htree_groups);
code_lengths =
(int*)WebPSafeCalloc((uint64_t)max_alphabet_size, sizeof(*code_lengths));
huff_codes =
(int*)WebPSafeMalloc((uint64_t)max_alphabet_size, sizeof(*huff_codes));
if (htree_groups == NULL || code_lengths == NULL || huff_codes == NULL) {
dec->status_ = VP8_STATUS_OUT_OF_MEMORY;
goto Error;
}
@ -354,12 +352,18 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
HuffmanTree* const htrees = htree_groups[i].htrees_;
for (j = 0; j < HUFFMAN_CODES_PER_META_CODE; ++j) {
int alphabet_size = kAlphabetSize[j];
HuffmanTree* const htree = htrees + j;
if (j == 0 && color_cache_bits > 0) {
alphabet_size += 1 << color_cache_bits;
}
if (!ReadHuffmanCode(alphabet_size, dec, htrees + j)) goto Error;
if (!ReadHuffmanCode(alphabet_size, dec, code_lengths, huff_codes,
htree)) {
goto Error;
}
}
}
WebPSafeFree(huff_codes);
WebPSafeFree(code_lengths);
// All OK. Finalize pointers and return.
hdr->huffman_image_ = huffman_image;
@ -368,8 +372,10 @@ static int ReadHuffmanCodes(VP8LDecoder* const dec, int xsize, int ysize,
return 1;
Error:
WebPSafeFree(huff_codes);
WebPSafeFree(code_lengths);
WebPSafeFree(huffman_image);
DeleteHtreeGroups(htree_groups, num_htree_groups);
VP8LHtreeGroupsFree(htree_groups, num_htree_groups);
return 0;
}
@ -1028,7 +1034,7 @@ static void ClearMetadata(VP8LMetadata* const hdr) {
assert(hdr);
WebPSafeFree(hdr->huffman_image_);
DeleteHtreeGroups(hdr->htree_groups_, hdr->num_htree_groups_);
VP8LHtreeGroupsFree(hdr->htree_groups_, hdr->num_htree_groups_);
VP8LColorCacheClear(&hdr->color_cache_);
InitMetadata(hdr);
}