Chat-O-Matic/libs/libmsn/libsiren/huffman.cpp

383 lines
11 KiB
C++

/*
* Siren Encoder/Decoder library
*
* @author: Youness Alaoui <kakaroto@kakaroto.homelinux.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "siren7.h"
#include "huffman_consts.h"
static short current_word = 0;
static int bit_idx = 0;
static int *bitstream_ptr = NULL;
int next_bit() {
if (bitstream_ptr == NULL)
return -1;
if (bit_idx == 0) {
current_word = *bitstream_ptr++;
bit_idx = 16;
}
return (current_word >> --bit_idx) & 1;
}
void set_bitstream(int *stream) {
bitstream_ptr = stream;
current_word = *bitstream_ptr;
bit_idx = 0;
}
int compute_region_powers(int number_of_regions, float *coefs, int *drp_num_bits, int *drp_code_bits, int *absolute_region_power_index, int esf_adjustment) {
float region_power = 0;
int num_bits;
int idx;
int max_idx, min_idx;
int region, i;
for (region = 0; region < number_of_regions; region++) {
region_power = 0.0f;
for (i = 0 ; i < region_size; i++) {
region_power += coefs[(region*region_size)+i] * coefs[(region*region_size)+i];
}
region_power *= region_size_inverse;
min_idx = 0;
max_idx = 64;
for (i = 0; i < 6; i++) {
idx = (min_idx + max_idx) / 2;
if (region_power_table_boundary[idx-1] <= region_power) {
min_idx = idx;
} else {
max_idx = idx;
}
}
absolute_region_power_index[region] = min_idx - 24;
}
for (region = number_of_regions-2; region >= 0; region--) {
if (absolute_region_power_index[region] < absolute_region_power_index[region+1] - 11)
absolute_region_power_index[region] = absolute_region_power_index[region+1] - 11;
}
if (absolute_region_power_index[0] < (1-esf_adjustment))
absolute_region_power_index[0] = (1-esf_adjustment);
if (absolute_region_power_index[0] > (31-esf_adjustment))
absolute_region_power_index[0] = (31-esf_adjustment);
drp_num_bits[0] = 5;
drp_code_bits[0] = absolute_region_power_index[0] + esf_adjustment;
for(region = 1; region < number_of_regions; region++) {
if (absolute_region_power_index[region] < (-8 - esf_adjustment))
absolute_region_power_index[region] = (-8 - esf_adjustment);
if (absolute_region_power_index[region] > (31-esf_adjustment))
absolute_region_power_index[region] = (31-esf_adjustment);
}
num_bits = 5;
for(region = 0; region < number_of_regions-1; region++) {
idx = absolute_region_power_index[region+1] - absolute_region_power_index[region] + 12;
if (idx < 0)
idx = 0;
absolute_region_power_index[region+1] = absolute_region_power_index[region] + idx - 12;
drp_num_bits[region+1] = differential_region_power_bits[region][idx];
drp_code_bits[region+1] = differential_region_power_codes[region][idx];
num_bits += drp_num_bits[region+1];
}
return num_bits;
}
int decode_envelope(int number_of_regions, float *decoder_standard_deviation, int *absolute_region_power_index, int esf_adjustment) {
int index;
int i;
int envelope_bits = 0;
index = 0;
for (i = 0; i < 5; i++)
index = (index<<1) | next_bit();
envelope_bits = 5;
absolute_region_power_index[0] = index - esf_adjustment;
decoder_standard_deviation[0] = standard_deviation[absolute_region_power_index[0] + 24];
for (i = 1; i < number_of_regions; i++) {
index = 0;
do {
index = differential_decoder_tree[i-1][index][next_bit()];
envelope_bits++;
} while (index > 0);
absolute_region_power_index[i] = absolute_region_power_index[i-1] - index - 12;
decoder_standard_deviation[i] = standard_deviation[absolute_region_power_index[i] + 24];
}
return envelope_bits;
}
static int huffman_vector(int category, int power_idx, float *mlts, int *out) {
int i, j;
float temp_value = deviation_inverse[power_idx] * step_size_inverse[category];
int sign_idx, idx, non_zeroes, max, bits_available;
int current_word = 0;
int region_bits = 0;
bits_available = 32;
for (i = 0; i < number_of_vectors[category]; i++) {
sign_idx = idx = non_zeroes = 0;
for (j = 0; j < vector_dimension[category]; j++) {
max = (int) ((fabs(*mlts) * temp_value) + dead_zone[category]);
if (max != 0) {
sign_idx <<= 1;
non_zeroes++;
if (*mlts > 0)
sign_idx++;
if (max > max_bin[category] || max < 0)
max = max_bin[category];
}
mlts++;
idx = (idx * (max_bin[category] + 1)) + max;
}
region_bits += bitcount_tables[category][idx] + non_zeroes;
bits_available -= bitcount_tables[category][idx] + non_zeroes;
if (bits_available < 0) {
*out++ = current_word + (((code_tables[category][idx] << non_zeroes) + sign_idx) >> -bits_available);
bits_available += 32;
current_word = ((code_tables[category][idx] << non_zeroes) + sign_idx) << bits_available;
} else {
current_word += ((code_tables[category][idx] << non_zeroes) + sign_idx) << bits_available;
}
}
*out = current_word;
return region_bits;
}
int quantize_mlt(int number_of_regions, int rate_control_possibilities, int number_of_available_bits, float *coefs, int *absolute_region_power_index, int *power_categories, int *category_balance, int *region_mlt_bit_counts, int *region_mlt_bits) {
int region;
int mlt_bits = 0;
int rate_control;
for (rate_control = 0; rate_control < ((rate_control_possibilities >> 1) - 1); rate_control++)
power_categories[category_balance[rate_control]]++;
for (region = 0; region < number_of_regions; region++) {
if (power_categories[region] > 6)
region_mlt_bit_counts[region] = 0;
else
region_mlt_bit_counts[region] = huffman_vector(power_categories[region], absolute_region_power_index[region], coefs + (region_size * region),
region_mlt_bits + (4*region));
mlt_bits += region_mlt_bit_counts[region];
}
while (mlt_bits < number_of_available_bits && rate_control > 0) {
rate_control--;
region = category_balance[rate_control];
power_categories[region]--;
if (power_categories[region] < 0)
power_categories[region] = 0;
mlt_bits -= region_mlt_bit_counts[region];
if (power_categories[region] > 6)
region_mlt_bit_counts[region] = 0;
else
region_mlt_bit_counts[region] = huffman_vector(power_categories[region], absolute_region_power_index[region], coefs + (region_size * region),
region_mlt_bits + (4*region));
mlt_bits += region_mlt_bit_counts[region];
}
while(mlt_bits > number_of_available_bits && rate_control < rate_control_possibilities) {
region = category_balance[rate_control];
power_categories[region]++;
mlt_bits -= region_mlt_bit_counts[region];
if (power_categories[region] > 6)
region_mlt_bit_counts[region] = 0;
else
region_mlt_bit_counts[region] = huffman_vector(power_categories[region], absolute_region_power_index[region], coefs + (region_size * region),
region_mlt_bits + (4*region));
mlt_bits += region_mlt_bit_counts[region];
rate_control++;
}
return rate_control;
}
static int get_dw(SirenDecoder decoder) {
int ret = decoder->dw1 + decoder->dw4;
if ((ret & 0x8000) != 0)
ret++;
decoder->dw1 = decoder->dw2;
decoder->dw2 = decoder->dw3;
decoder->dw3 = decoder->dw4;
decoder->dw4 = ret;
return ret;
}
int decode_vector(SirenDecoder decoder, int number_of_regions, int number_of_available_bits, float *decoder_standard_deviation, int *power_categories, float *coefs, int scale_factor) {
float *coefs_ptr;
float decoded_value;
float noise;
int *decoder_tree;
int region;
int category;
int i, j;
int index;
int error;
int dw1;
int dw2;
error = 0;
for (region = 0; region < number_of_regions; region++) {
category = power_categories[region];
coefs_ptr = coefs + (region * region_size);
if (category < 7) {
decoder_tree = decoder_tables[category];
for (i = 0; i < number_of_vectors[category]; i++) {
index = 0;
do {
if (number_of_available_bits <= 0) {
error = 1;
break;
}
index = decoder_tree[index + next_bit()];
number_of_available_bits--;
} while ((index & 1) == 0);
index >>= 1;
if (error == 0 && number_of_available_bits >= 0) {
for (j = 0; j < vector_dimension[category]; j++) {
decoded_value = mlt_quant[category][index & ((1 << index_table[category]) - 1)];
index >>= index_table[category];
if (decoded_value != 0) {
if (next_bit() == 0)
decoded_value *= -decoder_standard_deviation[region];
else
decoded_value *= decoder_standard_deviation[region];
number_of_available_bits--;
}
*coefs_ptr++ = decoded_value * scale_factor;
}
} else {
error = 1;
break;
}
}
if (error == 1) {
for (j = region + 1; j < number_of_regions; j++)
power_categories[j] = 7;
category = 7;
}
}
coefs_ptr = coefs + (region * region_size);
if (category == 5) {
i = 0;
for (j = 0; j < region_size; j++) {
if (*coefs_ptr != 0) {
i++;
if (fabs(*coefs_ptr) > 2.0 * decoder_standard_deviation[region]) {
i += 3;
}
}
coefs_ptr++;
}
noise = decoder_standard_deviation[region] * noise_category5[i];
} else if (category == 6) {
i = 0;
for (j = 0; j < region_size; j++) {
if (*coefs_ptr++ != 0)
i++;
}
noise = decoder_standard_deviation[region] * noise_category6[i];
} else if (category == 7) {
noise = decoder_standard_deviation[region] * noise_category7;
} else {
noise = 0;
}
coefs_ptr = coefs + (region * region_size);
if (category == 5 || category == 6 || category == 7) {
dw1 = get_dw(decoder);
dw2 = get_dw(decoder);
for (j=0; j<10; j++) {
if (category == 7 || *coefs_ptr == 0) {
if ((dw1 & 1))
*coefs_ptr = noise;
else
*coefs_ptr = -noise;
}
coefs_ptr++;
dw1 >>= 1;
if (category == 7 || *coefs_ptr == 0) {
if ((dw2 & 1))
*coefs_ptr = noise;
else
*coefs_ptr = -noise;
}
coefs_ptr++;
dw2 >>= 1;
}
}
}
return error == 1 ? -1 : number_of_available_bits;
}