123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286 |
- // Copyright 2011 Google Inc. All Rights Reserved.
- //
- // Use of this source code is governed by a BSD-style license
- // that can be found in the COPYING file in the root of the source
- // tree. An additional intellectual property rights grant can be found
- // in the file PATENTS. All contributing project authors may
- // be found in the AUTHORS file in the root of the source tree.
- // -----------------------------------------------------------------------------
- //
- // Paginated token buffer
- //
- // A 'token' is a bit value associated with a probability, either fixed
- // or a later-to-be-determined after statistics have been collected.
- // For dynamic probability, we just record the slot id (idx) for the probability
- // value in the final probability array (uint8_t* probas in VP8EmitTokens).
- //
- // Author: Skal (pascal.massimino@gmail.com)
- #include <assert.h>
- #include <stdlib.h>
- #include <string.h>
- #include "./cost.h"
- #include "./vp8enci.h"
- #include "../utils/utils.h"
- #if !defined(DISABLE_TOKEN_BUFFER)
- // we use pages to reduce the number of memcpy()
- #define MIN_PAGE_SIZE 8192 // minimum number of token per page
- #define FIXED_PROBA_BIT (1u << 14)
- typedef uint16_t token_t; // bit#15: bit
- // bit #14: constant proba or idx
- // bits 0..13: slot or constant proba
- struct VP8Tokens {
- VP8Tokens* next_; // pointer to next page
- };
- // Token data is located in memory just after the next_ field.
- // This macro is used to return their address and hide the trick.
- #define TOKEN_DATA(p) ((token_t*)&(p)[1])
- //------------------------------------------------------------------------------
- void VP8TBufferInit(VP8TBuffer* const b, int page_size) {
- b->tokens_ = NULL;
- b->pages_ = NULL;
- b->last_page_ = &b->pages_;
- b->left_ = 0;
- b->page_size_ = (page_size < MIN_PAGE_SIZE) ? MIN_PAGE_SIZE : page_size;
- b->error_ = 0;
- }
- void VP8TBufferClear(VP8TBuffer* const b) {
- if (b != NULL) {
- const VP8Tokens* p = b->pages_;
- while (p != NULL) {
- const VP8Tokens* const next = p->next_;
- WebPSafeFree((void*)p);
- p = next;
- }
- VP8TBufferInit(b, b->page_size_);
- }
- }
- static int TBufferNewPage(VP8TBuffer* const b) {
- VP8Tokens* page = NULL;
- const size_t size = sizeof(*page) + b->page_size_ * sizeof(token_t);
- if (!b->error_) {
- page = (VP8Tokens*)WebPSafeMalloc(1ULL, size);
- }
- if (page == NULL) {
- b->error_ = 1;
- return 0;
- }
- page->next_ = NULL;
- *b->last_page_ = page;
- b->last_page_ = &page->next_;
- b->left_ = b->page_size_;
- b->tokens_ = TOKEN_DATA(page);
- return 1;
- }
- //------------------------------------------------------------------------------
- #define TOKEN_ID(t, b, ctx, p) \
- ((p) + NUM_PROBAS * ((ctx) + NUM_CTX * ((b) + NUM_BANDS * (t))))
- static WEBP_INLINE int AddToken(VP8TBuffer* const b,
- int bit, uint32_t proba_idx) {
- assert(proba_idx < FIXED_PROBA_BIT);
- assert(bit == 0 || bit == 1);
- if (b->left_ > 0 || TBufferNewPage(b)) {
- const int slot = --b->left_;
- b->tokens_[slot] = (bit << 15) | proba_idx;
- }
- return bit;
- }
- static WEBP_INLINE void AddConstantToken(VP8TBuffer* const b,
- int bit, int proba) {
- assert(proba < 256);
- assert(bit == 0 || bit == 1);
- if (b->left_ > 0 || TBufferNewPage(b)) {
- const int slot = --b->left_;
- b->tokens_[slot] = (bit << 15) | FIXED_PROBA_BIT | proba;
- }
- }
- int VP8RecordCoeffTokens(int ctx, int coeff_type, int first, int last,
- const int16_t* const coeffs,
- VP8TBuffer* const tokens) {
- int n = first;
- uint32_t base_id = TOKEN_ID(coeff_type, n, ctx, 0);
- if (!AddToken(tokens, last >= 0, base_id + 0)) {
- return 0;
- }
- while (n < 16) {
- const int c = coeffs[n++];
- const int sign = c < 0;
- int v = sign ? -c : c;
- if (!AddToken(tokens, v != 0, base_id + 1)) {
- ctx = 0;
- base_id = TOKEN_ID(coeff_type, VP8EncBands[n], ctx, 0);
- continue;
- }
- if (!AddToken(tokens, v > 1, base_id + 2)) {
- ctx = 1;
- } else {
- if (!AddToken(tokens, v > 4, base_id + 3)) {
- if (AddToken(tokens, v != 2, base_id + 4))
- AddToken(tokens, v == 4, base_id + 5);
- } else if (!AddToken(tokens, v > 10, base_id + 6)) {
- if (!AddToken(tokens, v > 6, base_id + 7)) {
- AddConstantToken(tokens, v == 6, 159);
- } else {
- AddConstantToken(tokens, v >= 9, 165);
- AddConstantToken(tokens, !(v & 1), 145);
- }
- } else {
- int mask;
- const uint8_t* tab;
- if (v < 3 + (8 << 1)) { // VP8Cat3 (3b)
- AddToken(tokens, 0, base_id + 8);
- AddToken(tokens, 0, base_id + 9);
- v -= 3 + (8 << 0);
- mask = 1 << 2;
- tab = VP8Cat3;
- } else if (v < 3 + (8 << 2)) { // VP8Cat4 (4b)
- AddToken(tokens, 0, base_id + 8);
- AddToken(tokens, 1, base_id + 9);
- v -= 3 + (8 << 1);
- mask = 1 << 3;
- tab = VP8Cat4;
- } else if (v < 3 + (8 << 3)) { // VP8Cat5 (5b)
- AddToken(tokens, 1, base_id + 8);
- AddToken(tokens, 0, base_id + 10);
- v -= 3 + (8 << 2);
- mask = 1 << 4;
- tab = VP8Cat5;
- } else { // VP8Cat6 (11b)
- AddToken(tokens, 1, base_id + 8);
- AddToken(tokens, 1, base_id + 10);
- v -= 3 + (8 << 3);
- mask = 1 << 10;
- tab = VP8Cat6;
- }
- while (mask) {
- AddConstantToken(tokens, !!(v & mask), *tab++);
- mask >>= 1;
- }
- }
- ctx = 2;
- }
- AddConstantToken(tokens, sign, 128);
- base_id = TOKEN_ID(coeff_type, VP8EncBands[n], ctx, 0);
- if (n == 16 || !AddToken(tokens, n <= last, base_id + 0)) {
- return 1; // EOB
- }
- }
- return 1;
- }
- #undef TOKEN_ID
- //------------------------------------------------------------------------------
- // This function works, but isn't currently used. Saved for later.
- #if 0
- static void Record(int bit, proba_t* const stats) {
- proba_t p = *stats;
- if (p >= 0xffff0000u) { // an overflow is inbound.
- p = ((p + 1u) >> 1) & 0x7fff7fffu; // -> divide the stats by 2.
- }
- // record bit count (lower 16 bits) and increment total count (upper 16 bits).
- p += 0x00010000u + bit;
- *stats = p;
- }
- void VP8TokenToStats(const VP8TBuffer* const b, proba_t* const stats) {
- const VP8Tokens* p = b->pages_;
- while (p != NULL) {
- const int N = (p->next_ == NULL) ? b->left_ : 0;
- int n = MAX_NUM_TOKEN;
- const token_t* const tokens = TOKEN_DATA(p);
- while (n-- > N) {
- const token_t token = tokens[n];
- if (!(token & FIXED_PROBA_BIT)) {
- Record((token >> 15) & 1, stats + (token & 0x3fffu));
- }
- }
- p = p->next_;
- }
- }
- #endif // 0
- //------------------------------------------------------------------------------
- // Final coding pass, with known probabilities
- int VP8EmitTokens(VP8TBuffer* const b, VP8BitWriter* const bw,
- const uint8_t* const probas, int final_pass) {
- const VP8Tokens* p = b->pages_;
- (void)final_pass;
- assert(!b->error_);
- while (p != NULL) {
- const VP8Tokens* const next = p->next_;
- const int N = (next == NULL) ? b->left_ : 0;
- int n = b->page_size_;
- const token_t* const tokens = TOKEN_DATA(p);
- while (n-- > N) {
- const token_t token = tokens[n];
- const int bit = (token >> 15) & 1;
- if (token & FIXED_PROBA_BIT) {
- VP8PutBit(bw, bit, token & 0xffu); // constant proba
- } else {
- VP8PutBit(bw, bit, probas[token & 0x3fffu]);
- }
- }
- if (final_pass) WebPSafeFree((void*)p);
- p = next;
- }
- if (final_pass) b->pages_ = NULL;
- return 1;
- }
- // Size estimation
- size_t VP8EstimateTokenSize(VP8TBuffer* const b, const uint8_t* const probas) {
- size_t size = 0;
- const VP8Tokens* p = b->pages_;
- assert(!b->error_);
- while (p != NULL) {
- const VP8Tokens* const next = p->next_;
- const int N = (next == NULL) ? b->left_ : 0;
- int n = b->page_size_;
- const token_t* const tokens = TOKEN_DATA(p);
- while (n-- > N) {
- const token_t token = tokens[n];
- const int bit = token & (1 << 15);
- if (token & FIXED_PROBA_BIT) {
- size += VP8BitCost(bit, token & 0xffu);
- } else {
- size += VP8BitCost(bit, probas[token & 0x3fffu]);
- }
- }
- p = next;
- }
- return size;
- }
- //------------------------------------------------------------------------------
- #else // DISABLE_TOKEN_BUFFER
- void VP8TBufferInit(VP8TBuffer* const b) {
- (void)b;
- }
- void VP8TBufferClear(VP8TBuffer* const b) {
- (void)b;
- }
- #endif // !DISABLE_TOKEN_BUFFER
|