INNER CODE UNIT · C
doRewrite
EhViewer-NekoInverter/EhViewer · app/src/main/cpp/gifutils.c:49
static void doRewrite(byte *addr, size_t size) {
if (size < 7 || !isGif(addr)) return;
for (size_t i = 0; i < size - 8; i++) {
// TODO: Optimize this hex find with SIMD?
if (addr[i] == FRAME_DELAY_START_MARKER[3] && addr[i + 1] == FRAME_DELAY_START_MARKER[2] &&
addr[i + 2] == FRAME_DELAY_START_MARKER[1] &&
addr[i + 3] == FRAME_DELAY_START_MARKER[0]) {
byte *end = addr + i + 4;
if (end[4] != 0) continue;
int frameDelay = end[2] << 8 | end[1];
if (frameDelay >= MINIMUM_FRAME_DELAY)
break; // Quit if the first block looks normal, for performance
end[1] = DEFAULT_FRAME_DELAY;
end[2] = 0;
}
}
}