mirror of
https://github.com/webmproject/libwebp.git
synced 2024-11-20 04:18:26 +01:00
trap two unchecked error conditions
CostModelBuild() and TrackBackwards() returns weren't checked
+ code clean-up
+ de-inline VP8LBackwardRefs non-critical methods
+ shuffle the .h around to group things together
+ extract some constants as #define's
+ fixed the "if (!(cc_init = ...)) {...}" constructs
+ removed some unneeded VP8L prefixes
Change-Id: Ic634cb87bc6b2033242d3e8e8731fab4c134f327
This commit is contained in:
Pascal Massimino
parent
87b4a908a5
commit
1875d926e7
@ -17,10 +17,30 @@
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#include "./backward_references.h"
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#include "./histogram.h"
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#include "../utils/color_cache.h"
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#include "../webp/format_constants.h"
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#define VALUES_IN_BYTE 256
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#define HASH_BITS 18
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#define HASH_SIZE (1 << HASH_BITS)
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#define HASH_MULTIPLIER (0xc6a4a7935bd1e995ULL)
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// 1M window (4M bytes) minus 120 special codes for short distances.
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#define WINDOW_SIZE ((1 << 20) - 120)
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// Bounds for the match length.
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#define MIN_LENGTH 2
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#define MAX_LENGTH 4096
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typedef struct {
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// Stores the most recently added position with the given hash value.
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int32_t hash_to_first_index_[HASH_SIZE];
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// chain_[pos] stores the previous position with the same hash value
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// for every pixel in the image.
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int32_t* chain_;
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} HashChain;
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// -----------------------------------------------------------------------------
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static const uint8_t plane_to_code_lut[128] = {
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96, 73, 55, 39, 23, 13, 5, 1, 255, 255, 255, 255, 255, 255, 255, 255,
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101, 78, 58, 42, 26, 16, 8, 2, 0, 3, 9, 17, 27, 43, 59, 79,
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@ -29,11 +49,9 @@ static const uint8_t plane_to_code_lut[128] = {
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110, 99, 82, 66, 48, 35, 30, 24, 22, 25, 31, 36, 49, 67, 83, 100,
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115, 108, 94, 76, 64, 50, 44, 40, 34, 41, 45, 51, 65, 77, 95, 109,
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118, 113, 103, 92, 80, 68, 60, 56, 54, 57, 61, 69, 81, 93, 104, 114,
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119, 116, 111, 106, 97, 88, 84, 74, 72, 75, 85, 89, 98, 107, 112, 117,
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119, 116, 111, 106, 97, 88, 84, 74, 72, 75, 85, 89, 98, 107, 112, 117
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};
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static const int kMinLength = 2;
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static int DistanceToPlaneCode(int xsize, int dist) {
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const int yoffset = dist / xsize;
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const int xoffset = dist - yoffset * xsize;
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@ -55,30 +73,44 @@ static WEBP_INLINE int FindMatchLength(const uint32_t* const array1,
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return match_len;
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}
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#define HASH_BITS 18
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#define HASH_SIZE (1 << HASH_BITS)
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static const uint64_t kHashMultiplier = 0xc6a4a7935bd1e995ULL;
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static const int kWindowSize = (1 << 20) - 120; // A window with 1M pixels
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// (4 megabytes) - 120
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// special codes for short
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// distances.
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// -----------------------------------------------------------------------------
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// VP8LBackwardRefs
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void VP8LInitBackwardRefs(VP8LBackwardRefs* const refs) {
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if (refs != NULL) {
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refs->refs = NULL;
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refs->size = 0;
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refs->max_size = 0;
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}
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}
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void VP8LClearBackwardRefs(VP8LBackwardRefs* const refs) {
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if (refs != NULL) {
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free(refs->refs);
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VP8LInitBackwardRefs(refs);
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}
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}
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int VP8LBackwardRefsAlloc(VP8LBackwardRefs* const refs, int max_size) {
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assert(refs != NULL);
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refs->size = 0;
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refs->max_size = 0;
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refs->refs = (PixOrCopy*)malloc(max_size * sizeof(*refs->refs));
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if (refs->refs == NULL) return 0;
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refs->max_size = max_size;
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return 1;
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}
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// -----------------------------------------------------------------------------
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// Hash chains
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static WEBP_INLINE uint64_t GetPixPairHash64(const uint32_t* const argb) {
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uint64_t key = ((uint64_t)(argb[1]) << 32) | argb[0];
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key *= kHashMultiplier;
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key >>= 64 - HASH_BITS;
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key = (key * HASH_MULTIPLIER) >> (64 - HASH_BITS);
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return key;
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}
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typedef struct {
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// Stores the most recently added position with the given hash value.
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int32_t hash_to_first_index_[HASH_SIZE];
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// chain_[pos] stores the previous position with the same hash value
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// for every pixel in the image.
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int32_t* chain_;
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} VP8LHashChain;
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static int VP8LHashChainInit(VP8LHashChain* const p, int size) {
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static int HashChainInit(HashChain* const p, int size) {
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int i;
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p->chain_ = (int*)malloc(size * sizeof(*p->chain_));
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if (p->chain_ == NULL) {
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@ -93,23 +125,25 @@ static int VP8LHashChainInit(VP8LHashChain* const p, int size) {
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return 1;
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}
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static void VP8LHashChainClear(VP8LHashChain* const p) {
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static void HashChainDelete(HashChain* const p) {
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if (p != NULL) {
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free(p->chain_);
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free(p);
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}
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}
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static void VP8LHashChainInsert(VP8LHashChain* const p,
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const uint32_t* const argb, int32_t pos) {
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// Insertion of two pixels at a time.
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static void HashChainInsert(HashChain* const p,
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const uint32_t* const argb, int pos) {
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const uint64_t hash_code = GetPixPairHash64(argb);
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p->chain_[pos] = p->hash_to_first_index_[hash_code];
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p->hash_to_first_index_[hash_code] = pos;
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}
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static int HashChainFindCopy(
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const VP8LHashChain* const p, int quality, int index, int xsize,
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const uint32_t* const argb, int maxlen, int* const distance_ptr,
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static int HashChainFindCopy(const HashChain* const p,
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int quality, int index, int xsize,
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const uint32_t* const argb, int maxlen,
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int* const distance_ptr,
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int* const length_ptr) {
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const uint64_t hash_code = GetPixPairHash64(&argb[index]);
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int prev_length = 0;
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@ -117,7 +151,7 @@ static int HashChainFindCopy(
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const int iter_min_mult = (quality < 50) ? 2 : (quality <= 75) ? 4 : 8;
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const int iter_min = -quality * iter_min_mult;
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int iter_cnt = 10 + (quality >> 1);
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const int min_pos = (index > kWindowSize) ? index - kWindowSize : 0;
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const int min_pos = (index > WINDOW_SIZE) ? index - WINDOW_SIZE : 0;
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int32_t pos;
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int64_t val;
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int best_length = 0;
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@ -162,7 +196,7 @@ static int HashChainFindCopy(
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best_val = val;
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best_length = curr_length;
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best_distance = index - pos;
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if (curr_length >= kMaxLength) {
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if (curr_length >= MAX_LENGTH) {
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break;
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}
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if ((best_distance == 1 || best_distance == xsize) &&
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@ -173,28 +207,32 @@ static int HashChainFindCopy(
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}
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*distance_ptr = best_distance;
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*length_ptr = best_length;
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return best_length >= kMinLength;
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return (best_length >= MIN_LENGTH);
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}
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static WEBP_INLINE void PushBackCopy(VP8LBackwardRefs* const refs, int length) {
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while (length >= kMaxLength) {
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refs->refs[refs->size++] = PixOrCopyCreateCopy(1, kMaxLength);
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length -= kMaxLength;
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int size = refs->size;
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while (length >= MAX_LENGTH) {
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refs->refs[size++] = PixOrCopyCreateCopy(1, MAX_LENGTH);
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length -= MAX_LENGTH;
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}
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if (length > 0) {
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refs->refs[refs->size++] = PixOrCopyCreateCopy(1, length);
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refs->refs[size++] = PixOrCopyCreateCopy(1, length);
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}
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refs->size = size;
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}
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static void BackwardReferencesRle(
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int xsize, int ysize, const uint32_t* const argb,
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static void BackwardReferencesRle(int xsize, int ysize,
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const uint32_t* const argb,
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VP8LBackwardRefs* const refs) {
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const int pix_count = xsize * ysize;
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int match_len = 0;
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int i;
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refs->size = 0;
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for (i = 0; i < pix_count; ++i) {
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if (i >= 1 && argb[i] == argb[i - 1]) {
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PushBackCopy(refs, match_len); // i=0 case
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refs->refs[refs->size++] = PixOrCopyCreateLiteral(argb[0]);
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for (i = 1; i < pix_count; ++i) {
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if (argb[i] == argb[i - 1]) {
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++match_len;
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} else {
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PushBackCopy(refs, match_len);
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@ -205,22 +243,23 @@ static void BackwardReferencesRle(
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PushBackCopy(refs, match_len);
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}
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static int BackwardReferencesHashChain(
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int xsize, int ysize, const uint32_t* const argb,
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int cache_bits, int quality, VP8LBackwardRefs* const refs) {
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static int BackwardReferencesHashChain(int xsize, int ysize,
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const uint32_t* const argb,
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int cache_bits, int quality,
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VP8LBackwardRefs* const refs) {
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int i;
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int ok = 0;
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int cc_init = 0;
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const int use_color_cache = (cache_bits > 0);
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const int pix_count = xsize * ysize;
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VP8LHashChain* hash_chain = (VP8LHashChain*)malloc(sizeof(*hash_chain));
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HashChain* const hash_chain = (HashChain*)malloc(sizeof(*hash_chain));
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VP8LColorCache hashers;
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if (hash_chain == NULL) return 0;
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if (!(cc_init = VP8LColorCacheInit(&hashers, cache_bits)) ||
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!VP8LHashChainInit(hash_chain, pix_count)) {
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goto Error;
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}
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cc_init = VP8LColorCacheInit(&hashers, cache_bits);
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if (!cc_init) goto Error;
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if (!HashChainInit(hash_chain, pix_count)) goto Error;
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refs->size = 0;
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for (i = 0; i < pix_count; ) {
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@ -229,23 +268,23 @@ static int BackwardReferencesHashChain(
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int len = 0;
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if (i < pix_count - 1) { // FindCopy(i,..) reads pixels at [i] and [i + 1].
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int maxlen = pix_count - i;
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if (maxlen > kMaxLength) {
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maxlen = kMaxLength;
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if (maxlen > MAX_LENGTH) {
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maxlen = MAX_LENGTH;
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}
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HashChainFindCopy(hash_chain, quality, i, xsize, argb, maxlen,
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&offset, &len);
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}
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if (len >= kMinLength) {
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if (len >= MIN_LENGTH) {
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// Alternative#2: Insert the pixel at 'i' as literal, and code the
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// pixels starting at 'i + 1' using backward reference.
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int offset2 = 0;
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int len2 = 0;
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int k;
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VP8LHashChainInsert(hash_chain, &argb[i], i);
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HashChainInsert(hash_chain, &argb[i], i);
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if (i < pix_count - 2) { // FindCopy(i+1,..) reads [i + 1] and [i + 2].
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int maxlen = pix_count - (i + 1);
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if (maxlen > kMaxLength) {
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maxlen = kMaxLength;
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if (maxlen > MAX_LENGTH) {
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maxlen = MAX_LENGTH;
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}
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HashChainFindCopy(hash_chain, quality,
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i + 1, xsize, argb, maxlen, &offset2, &len2);
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@ -264,15 +303,15 @@ static int BackwardReferencesHashChain(
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offset = offset2;
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}
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}
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if (len >= kMaxLength) {
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len = kMaxLength - 1;
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if (len >= MAX_LENGTH) {
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len = MAX_LENGTH - 1;
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}
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refs->refs[refs->size++] = PixOrCopyCreateCopy(offset, len);
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for (k = 0; k < len; ++k) {
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VP8LColorCacheInsert(&hashers, argb[i + k]);
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if (k != 0 && i + k + 1 < pix_count) {
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// Add to the hash_chain (but cannot add the last pixel).
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VP8LHashChainInsert(hash_chain, &argb[i + k], i + k);
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HashChainInsert(hash_chain, &argb[i + k], i + k);
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}
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}
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i += len;
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@ -287,7 +326,7 @@ static int BackwardReferencesHashChain(
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++refs->size;
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VP8LColorCacheInsert(&hashers, argb[i]);
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if (i + 1 < pix_count) {
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VP8LHashChainInsert(hash_chain, &argb[i], i);
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HashChainInsert(hash_chain, &argb[i], i);
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}
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++i;
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}
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@ -295,8 +334,7 @@ static int BackwardReferencesHashChain(
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ok = 1;
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Error:
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if (cc_init) VP8LColorCacheClear(&hashers);
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VP8LHashChainClear(hash_chain);
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free(hash_chain);
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HashChainDelete(hash_chain);
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return ok;
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}
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@ -339,16 +377,15 @@ static int CostModelBuild(CostModel* const p, int xsize, int ysize,
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}
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VP8LHistogramCreate(&histo, &refs, cache_bits);
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VP8LConvertPopulationCountTableToBitEstimates(
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VP8LHistogramNumCodes(&histo),
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&histo.literal_[0], &p->literal_[0]);
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VP8LHistogramNumCodes(&histo), histo.literal_, p->literal_);
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VP8LConvertPopulationCountTableToBitEstimates(
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VALUES_IN_BYTE, &histo.red_[0], &p->red_[0]);
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VALUES_IN_BYTE, histo.red_, p->red_);
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VP8LConvertPopulationCountTableToBitEstimates(
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VALUES_IN_BYTE, &histo.blue_[0], &p->blue_[0]);
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VALUES_IN_BYTE, histo.blue_, p->blue_);
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VP8LConvertPopulationCountTableToBitEstimates(
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VALUES_IN_BYTE, &histo.alpha_[0], &p->alpha_[0]);
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VALUES_IN_BYTE, histo.alpha_, p->alpha_);
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VP8LConvertPopulationCountTableToBitEstimates(
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NUM_DISTANCE_CODES, &histo.distance_[0], &p->distance_[0]);
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NUM_DISTANCE_CODES, histo.distance_, p->distance_);
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ok = 1;
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Error:
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@ -391,23 +428,25 @@ static int BackwardReferencesHashChainDistanceOnly(
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const int quality = 100;
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const int pix_count = xsize * ysize;
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const int use_color_cache = (cache_bits > 0);
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double* cost = (double*)malloc(pix_count * sizeof(*cost));
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double* const cost = (double*)malloc(pix_count * sizeof(*cost));
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CostModel* cost_model = (CostModel*)malloc(sizeof(*cost_model));
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VP8LHashChain* hash_chain = (VP8LHashChain*)malloc(sizeof(*hash_chain));
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HashChain* hash_chain = (HashChain*)malloc(sizeof(*hash_chain));
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VP8LColorCache hashers;
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const double mul0 = (recursive_cost_model != 0) ? 1.0 : 0.68;
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const double mul1 = (recursive_cost_model != 0) ? 1.0 : 0.82;
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if (cost == NULL ||
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cost_model == NULL ||
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hash_chain == NULL ||
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!(cc_init = VP8LColorCacheInit(&hashers, cache_bits)) ||
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!VP8LHashChainInit(hash_chain, pix_count)) {
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if (cost == NULL || cost_model == NULL || hash_chain == NULL) goto Error;
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cc_init = VP8LColorCacheInit(&hashers, cache_bits);
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if (!cc_init || !HashChainInit(hash_chain, pix_count)) goto Error;
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if (!CostModelBuild(cost_model, xsize, ysize, recursive_cost_model, argb,
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cache_bits)) {
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goto Error;
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}
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CostModelBuild(cost_model, xsize, ysize, recursive_cost_model, argb,
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cache_bits);
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for (i = 0; i < pix_count; ++i) {
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cost[i] = 1e100;
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}
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for (i = 0; i < pix_count; ++i) cost[i] = 1e100;
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// We loop one pixel at a time, but store all currently best points to
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// non-processed locations from this point.
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dist_array[0] = 0;
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@ -421,14 +460,14 @@ static int BackwardReferencesHashChainDistanceOnly(
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int offset = 0;
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int len = 0;
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if (i < pix_count - 1) { // FindCopy reads pixels at [i] and [i + 1].
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int maxlen = shortmax ? 2 : kMaxLength;
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int maxlen = shortmax ? 2 : MAX_LENGTH;
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if (maxlen > pix_count - i) {
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maxlen = pix_count - i;
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}
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HashChainFindCopy(hash_chain, quality, i, xsize, argb, maxlen,
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&offset, &len);
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}
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if (len >= kMinLength) {
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if (len >= MIN_LENGTH) {
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const int code = DistanceToPlaneCode(xsize, offset);
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const double distance_cost =
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prev_cost + GetDistanceCost(cost_model, code);
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@ -451,7 +490,7 @@ static int BackwardReferencesHashChainDistanceOnly(
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VP8LColorCacheInsert(&hashers, argb[i + k]);
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if (i + k + 1 < pix_count) {
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// Add to the hash_chain (but cannot add the last pixel).
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VP8LHashChainInsert(hash_chain, &argb[i + k], i + k);
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HashChainInsert(hash_chain, &argb[i + k], i + k);
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}
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}
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// 2) jump.
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@ -461,19 +500,13 @@ static int BackwardReferencesHashChainDistanceOnly(
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}
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}
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if (i < pix_count - 1) {
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VP8LHashChainInsert(hash_chain, &argb[i], i);
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HashChainInsert(hash_chain, &argb[i], i);
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}
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{
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// inserting a literal pixel
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double cost_val = prev_cost;
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double mul0 = 1.0;
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double mul1 = 1.0;
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if (recursive_cost_model == 0) {
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mul0 = 0.68;
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mul1 = 0.82;
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}
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if (use_color_cache && VP8LColorCacheContains(&hashers, argb[i])) {
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int ix = VP8LColorCacheGetIndex(&hashers, argb[i]);
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const int ix = VP8LColorCacheGetIndex(&hashers, argb[i]);
|
||||
cost_val += GetCacheCost(cost_model, ix) * mul0;
|
||||
} else {
|
||||
cost_val += GetLiteralCost(cost_model, argb[i]) * mul1;
|
||||
@ -491,16 +524,16 @@ static int BackwardReferencesHashChainDistanceOnly(
|
||||
ok = 1;
|
||||
Error:
|
||||
if (cc_init) VP8LColorCacheClear(&hashers);
|
||||
VP8LHashChainClear(hash_chain);
|
||||
free(hash_chain);
|
||||
HashChainDelete(hash_chain);
|
||||
free(cost_model);
|
||||
free(cost);
|
||||
return ok;
|
||||
}
|
||||
|
||||
static void TraceBackwards(
|
||||
const uint32_t* const dist_array, int dist_array_size,
|
||||
uint32_t** const chosen_path, int* const chosen_path_size) {
|
||||
static int TraceBackwards(const uint32_t* const dist_array,
|
||||
int dist_array_size,
|
||||
uint32_t** const chosen_path,
|
||||
int* const chosen_path_size) {
|
||||
int i;
|
||||
// Count how many.
|
||||
int count = 0;
|
||||
@ -513,6 +546,8 @@ static void TraceBackwards(
|
||||
// Allocate.
|
||||
*chosen_path_size = count;
|
||||
*chosen_path = (uint32_t*)malloc(count * sizeof(*chosen_path));
|
||||
if (*chosen_path == NULL) return 0;
|
||||
|
||||
// Write in reverse order.
|
||||
for (i = dist_array_size - 1; i >= 0; ) {
|
||||
int k = dist_array[i];
|
||||
@ -520,6 +555,7 @@ static void TraceBackwards(
|
||||
(*chosen_path)[--count] = k;
|
||||
i -= k;
|
||||
}
|
||||
return 1;
|
||||
}
|
||||
|
||||
static int BackwardReferencesHashChainFollowChosenPath(
|
||||
@ -535,12 +571,12 @@ static int BackwardReferencesHashChainFollowChosenPath(
|
||||
int ix;
|
||||
int ok = 0;
|
||||
int cc_init = 0;
|
||||
VP8LHashChain* hash_chain = (VP8LHashChain*)malloc(sizeof(*hash_chain));
|
||||
HashChain* hash_chain = (HashChain*)malloc(sizeof(*hash_chain));
|
||||
VP8LColorCache hashers;
|
||||
|
||||
if (hash_chain == NULL ||
|
||||
!(cc_init = VP8LColorCacheInit(&hashers, cache_bits)) ||
|
||||
!VP8LHashChainInit(hash_chain, pix_count)) {
|
||||
!HashChainInit(hash_chain, pix_count)) {
|
||||
goto Error;
|
||||
}
|
||||
|
||||
@ -558,7 +594,7 @@ static int BackwardReferencesHashChainFollowChosenPath(
|
||||
VP8LColorCacheInsert(&hashers, argb[i + k]);
|
||||
if (i + k + 1 < pix_count) {
|
||||
// Add to the hash_chain (but cannot add the last pixel).
|
||||
VP8LHashChainInsert(hash_chain, &argb[i + k], i + k);
|
||||
HashChainInsert(hash_chain, &argb[i + k], i + k);
|
||||
}
|
||||
}
|
||||
i += len;
|
||||
@ -572,7 +608,7 @@ static int BackwardReferencesHashChainFollowChosenPath(
|
||||
}
|
||||
VP8LColorCacheInsert(&hashers, argb[i]);
|
||||
if (i + 1 < pix_count) {
|
||||
VP8LHashChainInsert(hash_chain, &argb[i], i);
|
||||
HashChainInsert(hash_chain, &argb[i], i);
|
||||
}
|
||||
++i;
|
||||
}
|
||||
@ -582,31 +618,35 @@ static int BackwardReferencesHashChainFollowChosenPath(
|
||||
ok = 1;
|
||||
Error:
|
||||
if (cc_init) VP8LColorCacheClear(&hashers);
|
||||
VP8LHashChainClear(hash_chain);
|
||||
free(hash_chain);
|
||||
HashChainDelete(hash_chain);
|
||||
return ok;
|
||||
}
|
||||
|
||||
// Returns 1 on success.
|
||||
static int BackwardReferencesTraceBackwards(
|
||||
int xsize, int ysize, int recursive_cost_model, const uint32_t* const argb,
|
||||
int cache_bits, VP8LBackwardRefs* const refs) {
|
||||
static int BackwardReferencesTraceBackwards(int xsize, int ysize,
|
||||
int recursive_cost_model,
|
||||
const uint32_t* const argb,
|
||||
int cache_bits,
|
||||
VP8LBackwardRefs* const refs) {
|
||||
int ok = 0;
|
||||
const int dist_array_size = xsize * ysize;
|
||||
uint32_t* chosen_path = NULL;
|
||||
int chosen_path_size = 0;
|
||||
uint32_t* const dist_array =
|
||||
uint32_t* dist_array =
|
||||
(uint32_t*)malloc(dist_array_size * sizeof(*dist_array));
|
||||
if (dist_array == NULL) {
|
||||
goto Error;
|
||||
}
|
||||
|
||||
if (dist_array == NULL) goto Error;
|
||||
|
||||
if (!BackwardReferencesHashChainDistanceOnly(
|
||||
xsize, ysize, recursive_cost_model, argb, cache_bits, dist_array)) {
|
||||
free(dist_array);
|
||||
goto Error;
|
||||
}
|
||||
TraceBackwards(dist_array, dist_array_size, &chosen_path, &chosen_path_size);
|
||||
free(dist_array);
|
||||
if (!TraceBackwards(dist_array, dist_array_size,
|
||||
&chosen_path, &chosen_path_size)) {
|
||||
goto Error;
|
||||
}
|
||||
free(dist_array); // no need to retain this memory any longer
|
||||
dist_array = NULL;
|
||||
if (!BackwardReferencesHashChainFollowChosenPath(
|
||||
xsize, ysize, argb, cache_bits, chosen_path, chosen_path_size, refs)) {
|
||||
goto Error;
|
||||
@ -614,6 +654,7 @@ static int BackwardReferencesTraceBackwards(
|
||||
ok = 1;
|
||||
Error:
|
||||
free(chosen_path);
|
||||
free(dist_array);
|
||||
return ok;
|
||||
}
|
||||
|
||||
@ -693,9 +734,8 @@ int VP8LGetBackwardReferences(int width, int height,
|
||||
*best = refs_rle;
|
||||
}
|
||||
|
||||
if (use_2d_locality) { // Use backward reference with 2D locality.
|
||||
BackwardReferences2DLocality(width, best);
|
||||
}
|
||||
if (use_2d_locality) BackwardReferences2DLocality(width, best);
|
||||
|
||||
ok = 1;
|
||||
|
||||
End:
|
||||
@ -706,17 +746,18 @@ int VP8LGetBackwardReferences(int width, int height,
|
||||
}
|
||||
|
||||
// Returns 1 on success.
|
||||
static int ComputeCacheHistogram(
|
||||
const uint32_t* const argb, int xsize, int ysize,
|
||||
const VP8LBackwardRefs* const refs, int cache_bits,
|
||||
static int ComputeCacheHistogram(const uint32_t* const argb,
|
||||
int xsize, int ysize,
|
||||
const VP8LBackwardRefs* const refs,
|
||||
int cache_bits,
|
||||
VP8LHistogram* const histo) {
|
||||
int pixel_index = 0;
|
||||
int i;
|
||||
uint32_t k;
|
||||
VP8LColorCache hashers;
|
||||
if (!VP8LColorCacheInit(&hashers, cache_bits)) {
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (!VP8LColorCacheInit(&hashers, cache_bits)) return 0;
|
||||
|
||||
for (i = 0; i < refs->size; ++i) {
|
||||
const PixOrCopy* const v = &refs->refs[i];
|
||||
if (PixOrCopyIsLiteral(v)) {
|
||||
@ -745,8 +786,8 @@ static int ComputeCacheHistogram(
|
||||
}
|
||||
|
||||
// Returns how many bits are to be used for a color cache.
|
||||
int VP8LCalculateEstimateForCacheSize(
|
||||
const uint32_t* const argb, int xsize, int ysize,
|
||||
int VP8LCalculateEstimateForCacheSize(const uint32_t* const argb,
|
||||
int xsize, int ysize,
|
||||
int* const best_cache_bits) {
|
||||
int ok = 0;
|
||||
int cache_bits;
|
||||
@ -758,7 +799,7 @@ int VP8LCalculateEstimateForCacheSize(
|
||||
!BackwardReferencesHashChain(xsize, ysize, argb, 0, quality, &refs)) {
|
||||
goto Error;
|
||||
}
|
||||
for (cache_bits = 0; cache_bits <= kColorCacheBitsMax; ++cache_bits) {
|
||||
for (cache_bits = 0; cache_bits <= MAX_COLOR_CACHE_BITS; ++cache_bits) {
|
||||
double cur_entropy;
|
||||
VP8LHistogram histo;
|
||||
VP8LHistogramInit(&histo, cache_bits);
|
||||
|
||||
@ -17,16 +17,22 @@
|
||||
#include <stdint.h>
|
||||
#include <stdlib.h>
|
||||
#include "../webp/types.h"
|
||||
#include "../webp/format_constants.h"
|
||||
|
||||
#if defined(__cplusplus) || defined(c_plusplus)
|
||||
extern "C" {
|
||||
#endif
|
||||
|
||||
// The spec allows 11, we use 9 bits to reduce memory consumption in encoding.
|
||||
// Having 9 instead of 11 removes about 0.25 % of compression density.
|
||||
static const int kColorCacheBitsMax = 9;
|
||||
#define PIX_OR_COPY_CODES_MAX (256 + 24 + (1 << 9))
|
||||
static const int kMaxLength = 4096;
|
||||
// Having 9 instead of 11 only removes about 0.25 % of compression density.
|
||||
#define MAX_COLOR_CACHE_BITS 9
|
||||
|
||||
// Max ever number of codes we'll use:
|
||||
#define PIX_OR_COPY_CODES_MAX \
|
||||
(NUM_LITERAL_CODES + NUM_LENGTH_CODES + (1 << MAX_COLOR_CACHE_BITS))
|
||||
|
||||
// -----------------------------------------------------------------------------
|
||||
// PrefixEncode()
|
||||
|
||||
// use GNU builtins where available.
|
||||
#if defined(__GNUC__) && \
|
||||
@ -36,16 +42,14 @@ static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
|
||||
}
|
||||
#else
|
||||
static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
|
||||
int log;
|
||||
uint32_t value;
|
||||
int log = 0;
|
||||
uint32_t value = n;
|
||||
int i;
|
||||
if (n == 0)
|
||||
return -1;
|
||||
log = 0;
|
||||
value = n;
|
||||
|
||||
if (value == 0) return -1;
|
||||
for (i = 4; i >= 0; --i) {
|
||||
int shift = (1 << i);
|
||||
uint32_t x = value >> shift;
|
||||
const int shift = (1 << i);
|
||||
const uint32_t x = value >> shift;
|
||||
if (x != 0) {
|
||||
value = x;
|
||||
log += shift;
|
||||
@ -56,7 +60,7 @@ static WEBP_INLINE int BitsLog2Floor(uint32_t n) {
|
||||
#endif
|
||||
|
||||
static WEBP_INLINE int VP8LBitsLog2Ceiling(uint32_t n) {
|
||||
int floor = BitsLog2Floor(n);
|
||||
const int floor = BitsLog2Floor(n);
|
||||
if (n == (n & ~(n - 1))) // zero or a power of two.
|
||||
return floor;
|
||||
else
|
||||
@ -66,28 +70,29 @@ static WEBP_INLINE int VP8LBitsLog2Ceiling(uint32_t n) {
|
||||
// Splitting of distance and length codes into prefixes and
|
||||
// extra bits. The prefixes are encoded with an entropy code
|
||||
// while the extra bits are stored just as normal bits.
|
||||
static WEBP_INLINE void PrefixEncode(
|
||||
int distance,
|
||||
int *code,
|
||||
int *extra_bits_count,
|
||||
int *extra_bits_value) {
|
||||
static WEBP_INLINE void PrefixEncode(int distance, int* const code,
|
||||
int* const extra_bits_count,
|
||||
int* const extra_bits_value) {
|
||||
// Collect the two most significant bits where the highest bit is 1.
|
||||
const int highest_bit = BitsLog2Floor(--distance);
|
||||
// & 0x3f is to make behavior well defined when highest_bit
|
||||
// does not exist or is the least significant bit.
|
||||
const int second_highest_bit =
|
||||
(distance >> ((highest_bit - 1) & 0x3f)) & 1;
|
||||
*extra_bits_count = (highest_bit > 0) ? highest_bit - 1 : 0;
|
||||
*extra_bits_count = (highest_bit > 0) ? (highest_bit - 1) : 0;
|
||||
*extra_bits_value = distance & ((1 << *extra_bits_count) - 1);
|
||||
*code = (highest_bit > 0) ? 2 * highest_bit + second_highest_bit :
|
||||
(highest_bit == 0) ? 1 : 0;
|
||||
*code = (highest_bit > 0) ? (2 * highest_bit + second_highest_bit)
|
||||
: (highest_bit == 0) ? 1 : 0;
|
||||
}
|
||||
|
||||
// -----------------------------------------------------------------------------
|
||||
// PixOrCopy
|
||||
|
||||
enum Mode {
|
||||
kLiteral,
|
||||
kCacheIdx,
|
||||
kCopy,
|
||||
kNone,
|
||||
kNone
|
||||
};
|
||||
|
||||
typedef struct {
|
||||
@ -97,7 +102,6 @@ typedef struct {
|
||||
uint32_t argb_or_distance;
|
||||
} PixOrCopy;
|
||||
|
||||
|
||||
static WEBP_INLINE PixOrCopy PixOrCopyCreateCopy(uint32_t distance,
|
||||
uint16_t len) {
|
||||
PixOrCopy retval;
|
||||
@ -110,7 +114,7 @@ static WEBP_INLINE PixOrCopy PixOrCopyCreateCopy(uint32_t distance,
|
||||
static WEBP_INLINE PixOrCopy PixOrCopyCreateCacheIdx(int idx) {
|
||||
PixOrCopy retval;
|
||||
assert(idx >= 0);
|
||||
assert(idx < (1 << kColorCacheBitsMax));
|
||||
assert(idx < (1 << MAX_COLOR_CACHE_BITS));
|
||||
retval.mode = kCacheIdx;
|
||||
retval.argb_or_distance = idx;
|
||||
retval.len = 1;
|
||||
@ -154,7 +158,7 @@ static WEBP_INLINE uint32_t PixOrCopyArgb(const PixOrCopy* const p) {
|
||||
|
||||
static WEBP_INLINE uint32_t PixOrCopyCacheIdx(const PixOrCopy* const p) {
|
||||
assert(p->mode == kCacheIdx);
|
||||
assert(p->argb_or_distance < (1U << kColorCacheBitsMax));
|
||||
assert(p->argb_or_distance < (1U << MAX_COLOR_CACHE_BITS));
|
||||
return p->argb_or_distance;
|
||||
}
|
||||
|
||||
@ -172,33 +176,17 @@ typedef struct {
|
||||
int max_size; // maximum capacity
|
||||
} VP8LBackwardRefs;
|
||||
|
||||
// Initialize the object. Must be called first. 'refs' can be NULL.
|
||||
void VP8LInitBackwardRefs(VP8LBackwardRefs* const refs);
|
||||
|
||||
static WEBP_INLINE void VP8LInitBackwardRefs(VP8LBackwardRefs* const refs) {
|
||||
if (refs != NULL) {
|
||||
refs->refs = NULL;
|
||||
refs->size = 0;
|
||||
refs->max_size = 0;
|
||||
}
|
||||
}
|
||||
|
||||
static WEBP_INLINE void VP8LClearBackwardRefs(VP8LBackwardRefs* const refs) {
|
||||
if (refs != NULL) {
|
||||
free(refs->refs);
|
||||
VP8LInitBackwardRefs(refs);
|
||||
}
|
||||
}
|
||||
// Release memory and re-initialize the object. 'refs' can be NULL.
|
||||
void VP8LClearBackwardRefs(VP8LBackwardRefs* const refs);
|
||||
|
||||
// Allocate 'max_size' references. Returns false in case of memory error.
|
||||
static WEBP_INLINE int VP8LBackwardRefsAlloc(VP8LBackwardRefs* const refs,
|
||||
int max_size) {
|
||||
assert(refs != NULL);
|
||||
refs->size = 0;
|
||||
refs->max_size = 0;
|
||||
refs->refs = (PixOrCopy*)malloc(max_size * sizeof(*refs->refs));
|
||||
if (refs->refs == NULL) return 0;
|
||||
refs->max_size = max_size;
|
||||
return 1;
|
||||
}
|
||||
int VP8LBackwardRefsAlloc(VP8LBackwardRefs* const refs, int max_size);
|
||||
|
||||
// -----------------------------------------------------------------------------
|
||||
// Main entry points
|
||||
|
||||
// Evaluates best possible backward references for specified quality.
|
||||
// Further optimize for 2D locality if use_2d_locality flag is set.
|
||||
@ -208,8 +196,8 @@ int VP8LGetBackwardReferences(int width, int height,
|
||||
VP8LBackwardRefs* const best);
|
||||
|
||||
// Produce an estimate for a good color cache size for the image.
|
||||
int VP8LCalculateEstimateForCacheSize(
|
||||
const uint32_t* const argb, int xsize, int ysize,
|
||||
int VP8LCalculateEstimateForCacheSize(const uint32_t* const argb,
|
||||
int xsize, int ysize,
|
||||
int* const best_cache_bits);
|
||||
|
||||
#if defined(__cplusplus) || defined(c_plusplus)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user