Ejemplo n.º 1
0
void ZopfliCopyLZ77Store(
    const ZopfliLZ77Store* source, ZopfliLZ77Store* dest) {
  size_t i;
  ZopfliCleanLZ77Store(dest);
  dest->litlens =
      (unsigned short*)malloc(sizeof(*dest->litlens) * source->size);
  dest->dists = (unsigned short*)malloc(sizeof(*dest->dists) * source->size);

  if (!dest->litlens || !dest->dists) exit(-1); /* Allocation failed. */

  dest->size = source->size;
  for (i = 0; i < source->size; i++) {
    dest->litlens[i] = source->litlens[i];
    dest->dists[i] = source->dists[i];
  }
}
Ejemplo n.º 2
0
void ZopfliBlockSplit(const ZopfliOptions* options,
                      const unsigned char* in, size_t instart, size_t inend,
                      size_t maxblocks, size_t** splitpoints, size_t* npoints) {
  size_t pos = 0;
  size_t i;
  ZopfliBlockState s;
  size_t* lz77splitpoints = 0;
  size_t nlz77points = 0;
  ZopfliLZ77Store store;
  ZopfliHash hash;
  ZopfliHash* h = &hash;

  ZopfliInitLZ77Store(in, &store);
  ZopfliInitBlockState(options, instart, inend, 0, &s);
  ZopfliAllocHash(ZOPFLI_WINDOW_SIZE, h);

  *npoints = 0;
  *splitpoints = 0;

  /* Unintuitively, Using a simple LZ77 method here instead of ZopfliLZ77Optimal
  results in better blocks. */
  ZopfliLZ77Greedy(&s, in, instart, inend, &store, h);

  ZopfliBlockSplitLZ77(options,
                       &store, maxblocks,
                       &lz77splitpoints, &nlz77points);

  /* Convert LZ77 positions to positions in the uncompressed input. */
  pos = instart;
  if (nlz77points > 0) {
    for (i = 0; i < store.size; i++) {
      size_t length = store.dists[i] == 0 ? 1 : store.litlens[i];
      if (lz77splitpoints[*npoints] == i) {
        ZOPFLI_APPEND_DATA(pos, splitpoints, npoints);
        if (*npoints == nlz77points) break;
      }
      pos += length;
    }
  }
  assert(*npoints == nlz77points);

  free(lz77splitpoints);
  ZopfliCleanBlockState(&s);
  ZopfliCleanLZ77Store(&store);
  ZopfliCleanHash(h);
}
Ejemplo n.º 3
0
void ZopfliBlockSplit(const ZopfliOptions* options,
                      const unsigned char* in, size_t instart, size_t inend,
                      size_t maxblocks, size_t** splitpoints, size_t* npoints, size_t* startnpoints) {
  size_t pos = 0;
  size_t i;
  ZopfliBlockState s;
  size_t* lz77splitpoints = 0;
  size_t nlz77points = 0;
  ZopfliLZ77Store store;

  ZopfliInitLZ77Store(&store);

  s.options = options;
  s.blockstart = instart;
  s.blockend = inend;
#ifdef ZOPFLI_LONGEST_MATCH_CACHE
  s.lmc = 0;
#endif

  *npoints = 0;
  *splitpoints = 0;

  /* Unintuitively, Using a simple LZ77 method here instead of ZopfliLZ77Optimal
  results in better blocks. */
  ZopfliLZ77Greedy(&s, in, instart, inend, &store, options);
  ZopfliBlockSplitLZ77(options,
                       store.litlens, store.dists, store.size, maxblocks,
                       &lz77splitpoints, &nlz77points, *startnpoints);
  /* Convert LZ77 positions to positions in the uncompressed input. */
  pos = instart;
  if (nlz77points > 0) {
    for (i = 0; i < store.size; i++) {
      size_t length = store.dists[i] == 0 ? 1 : store.litlens[i];
      if (lz77splitpoints[*npoints] == i) {
        ZOPFLI_APPEND_DATA(pos, splitpoints, npoints);
        if (*npoints == nlz77points) break;
      }
      pos += length;
    }
  }
  assert(*npoints == nlz77points);

  free(lz77splitpoints);
  ZopfliCleanLZ77Store(&store);
}