uint8_t curbit = (sample[p / 8] & ((uint8_t) 1 << (p % 8)));
uint8_t prevbit = (ctx->prevsample[p / 8] &
((uint8_t) 1 << (p % 8)));
uint8_t curbit = (sample[p / 8] & ((uint8_t) 1 << (p % 8)));
uint8_t prevbit = (ctx->prevsample[p / 8] &
((uint8_t) 1 << (p % 8)));