liblzma/rangecoder/range_encoder.h

55 rc_reset(lzma_range_encoder *rc)
57 	rc->low = 0;
58 	rc->cache_size = 1;
59 	rc->range = UINT32_MAX;
60 	rc->cache = 0;
61 	rc->count = 0;
62 	rc->pos = 0;
67 rc_bit(lzma_range_encoder *rc, probability *prob, uint32_t bit)
69 	rc->symbols[rc->count] = bit;
70 	rc->probs[rc->count] = prob;
71 	++rc->count;
76 rc_bittree(lzma_range_encoder *rc, probability *probs,
83 		rc_bit(rc, &probs[model_index], bit);
90 rc_bittree_reverse(lzma_range_encoder *rc, probability *probs,
98 		rc_bit(rc, &probs[model_index], bit);
105 rc_direct(lzma_range_encoder *rc,
109 		rc->symbols[rc->count++]
116 rc_flush(lzma_range_encoder *rc)
119 		rc->symbols[rc->count++] = RC_FLUSH;
124 rc_shift_low(lzma_range_encoder *rc,
127 	if ((uint32_t)(rc->low) < (uint32_t)(0xFF000000)
128 			|| (uint32_t)(rc->low >> 32) != 0) {
133 			out[*out_pos] = rc->cache + (uint8_t)(rc->low >> 32);
135 			rc->cache = 0xFF;
137 		} while (--rc->cache_size != 0);
139 		rc->cache = (rc->low >> 24) & 0xFF;
142 	++rc->cache_size;
143 	rc->low = (rc->low & 0x00FFFFFF) << RC_SHIFT_BITS;
150 rc_encode(lzma_range_encoder *rc,
153 	assert(rc->count <= RC_SYMBOLS_MAX);
155 	while (rc->pos < rc->count) {
157 		if (rc->range < RC_TOP_VALUE) {
158 			if (rc_shift_low(rc, out, out_pos, out_size))
161 			rc->range <<= RC_SHIFT_BITS;
165 		switch (rc->symbols[rc->pos]) {
167 			probability prob = *rc->probs[rc->pos];
168 			rc->range = (rc->range >> RC_BIT_MODEL_TOTAL_BITS)
171 			*rc->probs[rc->pos] = prob;
176 			probability prob = *rc->probs[rc->pos];
177 			const uint32_t bound = prob * (rc->range
179 			rc->low += bound;
180 			rc->range -= bound;
182 			*rc->probs[rc->pos] = prob;
187 			rc->range >>= 1;
191 			rc->range >>= 1;
192 			rc->low += rc->range;
197 			rc->range = UINT32_MAX;
201 				if (rc_shift_low(rc, out, out_pos, out_size))
203 			} while (++rc->pos < rc->count);
207 			rc_reset(rc);
215 		++rc->pos;
218 	rc->count = 0;
219 	rc->pos = 0;
226 rc_pending(const lzma_range_encoder *rc)
228 	return rc->cache_size + 5 - 1;