/**
*
*
* <PRE>
* -oo dB => -1.00
* - 6 dB => -0.97
* - 3 dB => -0.80
* - 2 dB => -0.64
* - 1 dB => -0.38
* 0 dB => 0.00
* + 1 dB => +0.49
* + 2 dB => +1.06
* + 3 dB => +1.68
* + 6 dB => +3.69
* +10 dB => +6.45
* </PRE>
*/
public final int calc_noise(
final GrInfo cod_info,
final float[] l3_xmin,
final float[] distort,
final CalcNoiseResult res,
final CalcNoiseData prev_noise) {
int distortPos = 0;
int l3_xminPos = 0;
int sfb, l, over = 0;
float over_noise_db = 0;
/* 0 dB relative to masking */
float tot_noise_db = 0;
/* -200 dB relative to masking */
float max_noise = -20.0f;
int j = 0;
final int[] scalefac = cod_info.scalefac;
int scalefacPos = 0;
res.over_SSD = 0;
for (sfb = 0; sfb < cod_info.psymax; sfb++) {
final int s =
cod_info.global_gain
- (((scalefac[scalefacPos++]) + (cod_info.preflag != 0 ? pretab[sfb] : 0))
<< (cod_info.scalefac_scale + 1))
- cod_info.subblock_gain[cod_info.window[sfb]] * 8;
float noise = 0.0f;
if (prev_noise != null && (prev_noise.step[sfb] == s)) {
/* use previously computed values */
noise = prev_noise.noise[sfb];
j += cod_info.width[sfb];
distort[distortPos++] = noise / l3_xmin[l3_xminPos++];
noise = prev_noise.noise_log[sfb];
} else {
final float step = POW20(s);
l = cod_info.width[sfb] >> 1;
if ((j + cod_info.width[sfb]) > cod_info.max_nonzero_coeff) {
int usefullsize;
usefullsize = cod_info.max_nonzero_coeff - j + 1;
if (usefullsize > 0) l = usefullsize >> 1;
else l = 0;
}
StartLine sl = new StartLine(j);
noise = calc_noise_core(cod_info, sl, l, step);
j = sl.s;
if (prev_noise != null) {
/* save noise values */
prev_noise.step[sfb] = s;
prev_noise.noise[sfb] = noise;
}
noise = distort[distortPos++] = noise / l3_xmin[l3_xminPos++];
/* multiplying here is adding in dB, but can overflow */
noise = Util.FAST_LOG10((float) Math.max(noise, 1E-20));
if (prev_noise != null) {
/* save noise values */
prev_noise.noise_log[sfb] = noise;
}
}
if (prev_noise != null) {
/* save noise values */
prev_noise.global_gain = cod_info.global_gain;
}
tot_noise_db += noise;
if (noise > 0.0) {
int tmp;
tmp = Math.max((int) (noise * 10 + .5), 1);
res.over_SSD += tmp * tmp;
over++;
/* multiplying here is adding in dB -but can overflow */
/* over_noise *= noise; */
over_noise_db += noise;
}
max_noise = Math.max(max_noise, noise);
}
res.over_count = over;
res.tot_noise = tot_noise_db;
res.over_noise = over_noise_db;
res.max_noise = max_noise;
return over;
}
/** count_bit */
public int noquant_count_bits(
final LameInternalFlags gfc, final GrInfo gi, CalcNoiseData prev_noise) {
final int[] ix = gi.l3_enc;
int i = Math.min(576, ((gi.max_nonzero_coeff + 2) >> 1) << 1);
if (prev_noise != null) prev_noise.sfb_count1 = 0;
/* Determine count1 region */
for (; i > 1; i -= 2) if ((ix[i - 1] | ix[i - 2]) != 0) break;
gi.count1 = i;
/* Determines the number of bits to encode the quadruples. */
int a1 = 0;
int a2 = 0;
for (; i > 3; i -= 4) {
int p;
/* hack to check if all values <= 1 */
if ((((long) ix[i - 1] | (long) ix[i - 2] | (long) ix[i - 3] | (long) ix[i - 4])
& 0xffffffffL)
> 1L) break;
p = ((ix[i - 4] * 2 + ix[i - 3]) * 2 + ix[i - 2]) * 2 + ix[i - 1];
a1 += Tables.t32l[p];
a2 += Tables.t33l[p];
}
int bits = a1;
gi.count1table_select = 0;
if (a1 > a2) {
bits = a2;
gi.count1table_select = 1;
}
gi.count1bits = bits;
gi.big_values = i;
if (i == 0) return bits;
if (gi.block_type == Encoder.SHORT_TYPE) {
a1 = 3 * gfc.scalefac_band.s[3];
if (a1 > gi.big_values) a1 = gi.big_values;
a2 = gi.big_values;
} else if (gi.block_type == Encoder.NORM_TYPE) {
assert (i <= 576); /* bv_scf has 576 entries (0..575) */
a1 = gi.region0_count = gfc.bv_scf[i - 2];
a2 = gi.region1_count = gfc.bv_scf[i - 1];
assert (a1 + a2 + 2 < Encoder.SBPSY_l);
a2 = gfc.scalefac_band.l[a1 + a2 + 2];
a1 = gfc.scalefac_band.l[a1 + 1];
if (a2 < i) {
Bits bi = new Bits(bits);
gi.table_select[2] = choose_table(ix, a2, i, bi);
bits = bi.bits;
}
} else {
gi.region0_count = 7;
/* gi.region1_count = SBPSY_l - 7 - 1; */
gi.region1_count = Encoder.SBMAX_l - 1 - 7 - 1;
a1 = gfc.scalefac_band.l[7 + 1];
a2 = i;
if (a1 > a2) {
a1 = a2;
}
}
/* have to allow for the case when bigvalues < region0 < region1 */
/* (and region0, region1 are ignored) */
a1 = Math.min(a1, i);
a2 = Math.min(a2, i);
assert (a1 >= 0);
assert (a2 >= 0);
/* Count the number of bits necessary to code the bigvalues region. */
if (0 < a1) {
Bits bi = new Bits(bits);
gi.table_select[0] = choose_table(ix, 0, a1, bi);
bits = bi.bits;
}
if (a1 < a2) {
Bits bi = new Bits(bits);
gi.table_select[1] = choose_table(ix, a1, a2, bi);
bits = bi.bits;
}
if (gfc.use_best_huffman == 2) {
gi.part2_3_length = bits;
best_huffman_divide(gfc, gi);
bits = gi.part2_3_length;
}
if (prev_noise != null) {
if (gi.block_type == Encoder.NORM_TYPE) {
int sfb = 0;
while (gfc.scalefac_band.l[sfb] < gi.big_values) {
sfb++;
}
prev_noise.sfb_count1 = sfb;
}
}
return bits;
}