summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--src/app/deflatetest/main.cc77
1 files changed, 60 insertions, 17 deletions
diff --git a/src/app/deflatetest/main.cc b/src/app/deflatetest/main.cc
index 21c48bd..221d881 100644
--- a/src/app/deflatetest/main.cc
+++ b/src/app/deflatetest/main.cc
@@ -100,23 +100,27 @@ static uint16_t udeflate_get_bits(uint8_t num_bits)
* sets. We don't do that; instead, we expect the uncompressed source to
* be no more than a few kB of data.
*/
-uint8_t udeflate_bl_count[12];
-uint16_t udeflate_next_code[12];
-// TODO specify bl_count and next_code lists
-// (length and distance codes may use separate alphabets)
-static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size)
+// used for huffman alphabet in type 2 and literal/length alphabet in type 1&2
+uint8_t udeflate_bl_count_ll[12];
+uint16_t udeflate_next_code_ll[12];
+
+// used for distance alphabet in types 1&2
+uint8_t udeflate_bl_count_d[12];
+uint16_t udeflate_next_code_d[12];
+
+static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size, uint8_t* bl_count, uint16_t* next_code)
{
uint16_t i;
uint16_t code = 0;
- uint8_t max_len = 0;
+ uint16_t max_len = 0;
for (i = 0; i < 12; i++) {
- udeflate_bl_count[i] = 0;
+ bl_count[i] = 0;
}
for (i = 0; i < size; i++) {
if (lengths[i]) {
- udeflate_bl_count[lengths[i]]++;
+ bl_count[lengths[i]]++;
}
if (lengths[i] > max_len) {
max_len = lengths[i];
@@ -124,26 +128,26 @@ static void udeflate_build_alphabet(uint8_t* lengths, uint16_t size)
}
for (i = 1; i < max_len+1; i++) {
- code = (code + udeflate_bl_count[i-1]) << 1;
- udeflate_next_code[i] = code;
+ code = (code + bl_count[i-1]) << 1;
+ next_code[i] = code;
}
for (i = 0; i < 12; i++) {
- kout << "bl_count[" << i << "] = " << udeflate_bl_count[i] << endl;
+ kout << "bl_count[" << i << "] = " << bl_count[i] << endl;
}
for (i = 0; i < 12; i++) {
- kout << "next_code[" << i << "] = " << udeflate_next_code[i] << endl;
+ kout << "next_code[" << i << "] = " << next_code[i] << endl;
}
}
-static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size)
+static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size, uint8_t* bl_count, uint16_t* next_code)
{
uint16_t next_word = udeflate_get_word();
for (uint8_t num_bits = 1; num_bits < 12; num_bits++) {
uint16_t next_bits = udeflate_rev_word(next_word, num_bits);
// TODO benötigt bit reversal bei der Abgleichung code <-> next_bits
// (geeignete is_bit_eq(next_bits, code_candidate, num_bits) Funktion?)
- if (udeflate_bl_count[num_bits] && next_bits >= udeflate_next_code[num_bits] && next_bits < udeflate_next_code[num_bits] + udeflate_bl_count[num_bits] ) {
+ if (bl_count[num_bits] && next_bits >= next_code[num_bits] && next_bits < next_code[num_bits] + bl_count[num_bits] ) {
kout << "found huffman code, length = " << num_bits << endl;
udeflate_bit_offset += num_bits;
while (udeflate_bit_offset >= 8) {
@@ -151,7 +155,7 @@ static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size)
udeflate_bit_offset -= 8;
}
uint8_t len_pos = next_bits;
- uint8_t cur_pos = udeflate_next_code[num_bits];
+ uint8_t cur_pos = next_code[num_bits];
for (uint16_t i = 0; i < size; i++) {
if (lengths[i] == num_bits) {
if (cur_pos == len_pos) {
@@ -165,6 +169,39 @@ static uint16_t udeflate_huff(uint8_t* lengths, uint16_t size)
return 65535;
}
+static int8_t udeflate_huffman(uint8_t* ll_lengths, uint16_t ll_size, uint8_t* d_lengths, uint8_t d_size)
+{
+ uint16_t code;
+ uint16_t dcode;
+ uint16_t output_pos = 0;
+ while (1) {
+ code = udeflate_huff(ll_lengths, ll_size, udeflate_bl_count_ll, udeflate_next_code_ll);
+ kout << "code " << code << endl;
+ if (code < 256) {
+ deflate_output[output_pos] = code;
+ output_pos++;
+ } else if (code == 256) {
+ return 0;
+ } else {
+ uint16_t len_val = udeflate_length_offsets[code - 257];
+ uint8_t extra_bits = udeflate_length_bits[code - 257];
+ if (extra_bits) {
+ len_val += udeflate_get_bits(extra_bits);
+ }
+ dcode = udeflate_huff(d_lengths, d_size, udeflate_bl_count_d, udeflate_next_code_d);
+ uint16_t dist_val = udeflate_distance_offsets[dcode];
+ extra_bits = udeflate_distance_bits[dcode];
+ if (extra_bits) {
+ dist_val += udeflate_get_bits(extra_bits);
+ }
+ while (len_val--) {
+ deflate_output[output_pos] = deflate_output[output_pos-dist_val];
+ output_pos++;
+ }
+ }
+ }
+}
+
static int8_t udeflate_dynamic_huffman()
{
uint8_t i;
@@ -182,11 +219,11 @@ static int8_t udeflate_dynamic_huffman()
udeflate_hc_lengths[udeflate_hclen_index[i]] = 0;
}
- udeflate_build_alphabet(udeflate_hc_lengths, sizeof(udeflate_hc_lengths));
+ udeflate_build_alphabet(udeflate_hc_lengths, sizeof(udeflate_hc_lengths), udeflate_bl_count_ll, udeflate_next_code_ll);
uint16_t items_processed = 0;
while (items_processed < hlit + hdist) {
- uint8_t code = udeflate_huff(udeflate_hc_lengths, 19);
+ uint8_t code = udeflate_huff(udeflate_hc_lengths, 19, udeflate_bl_count_ll, udeflate_next_code_ll);
kout << "code = " << code << endl;
if (code == 16) {
uint8_t copy_count = 3 + udeflate_get_bits(2);
@@ -215,6 +252,11 @@ static int8_t udeflate_dynamic_huffman()
}
}
+ udeflate_build_alphabet(udeflate_lld_lengths, hlit, udeflate_bl_count_ll, udeflate_next_code_ll);
+ udeflate_build_alphabet(udeflate_lld_lengths + hlit, hdist, udeflate_bl_count_d, udeflate_next_code_d);
+
+ return udeflate_huffman(udeflate_lld_lengths, hlit, udeflate_lld_lengths + hlit, hdist);
+
return 0;
}
@@ -266,6 +308,7 @@ int main(void)
for (uint8_t i = 0; i < 5; i++) {
int8_t ret = udeflate_zlib((unsigned char*)deflate_input, sizeof(deflate_input));
kout << "udeflate returned " << ret << endl;
+ kout << "Output: " << (char*)deflate_output << endl;
}
arch.idle();