public virtual void powerCompensation(ChannelUnitContext ctx, int chIndex, float[] sp, int rngIndex, int sb)
{
float[] pwcsp = new float[ATRAC3P_SUBBAND_SAMPLES];
int gcv = 0;
int swapCh = (ctx.unitType == CH_UNIT_STEREO && ctx.swapChannels[sb] ? 1 : 0);
if (ctx.channels[chIndex ^ swapCh].powerLevs[subband_to_powgrp[sb]] == ATRAC3P_POWER_COMP_OFF)
{
return;
}
// generate initial noise spectrum
for (int i = 0; i < ATRAC3P_SUBBAND_SAMPLES; i++, rngIndex++)
{
pwcsp[i] = noise_tab[rngIndex & 0x3FF];
}
// check gain control information
AtracGainInfo g1 = ctx.channels[chIndex ^ swapCh].gainData[sb];
AtracGainInfo g2 = ctx.channels[chIndex ^ swapCh].gainDataPrev[sb];
int gainLev = (g1.numPoints > 0 ? (6 - g1.levCode[0]) : 0);
for (int i = 0; i < g2.numPoints; i++)
{
gcv = max(gcv, gainLev - (g2.levCode[i] - 6));
}
for (int i = 0; i < g1.numPoints; i++)
{
gcv = max(gcv, 6 - g1.levCode[i]);
}
float grpLev = pwc_levs[ctx.channels[chIndex ^ swapCh].powerLevs[subband_to_powgrp[sb]]] / (1 << gcv);
// skip the lowest two quant units (frequencies 0...351 Hz) for subband 0
for (int qu = subband_to_qu[sb] + (sb == 0 ? 2 : 0); qu < subband_to_qu[sb + 1]; qu++)
{
if (ctx.channels[chIndex].quWordlen[qu] <= 0)
{
continue;
}
float quLev = ff_atrac3p_sf_tab[ctx.channels[chIndex].quSfIdx[qu]] * ff_atrac3p_mant_tab[ctx.channels[chIndex].quWordlen[qu]] / (1 << ctx.channels[chIndex].quWordlen[qu]) * grpLev;
int dst = ff_atrac3p_qu_to_spec_pos[qu];
int nsp = ff_atrac3p_qu_to_spec_pos[qu + 1] - ff_atrac3p_qu_to_spec_pos[qu];
for (int i = 0; i < nsp; i++)
{
sp[dst + i] += pwcsp[i] * quLev;
}
}
}
public virtual void generateTones(ChannelUnitContext ctx, int chNum, int sb, float[] @out, int outOffset)
{
float[] wavreg1 = new float[128];
float[] wavreg2 = new float[128];
WavesData tonesNow = ctx.channels[chNum].tonesInfoPrev[sb];
WavesData tonesNext = ctx.channels[chNum].tonesInfo[sb];
// reconstruct full envelopes for both overlapping regions
// from truncated bitstream data
if (tonesNext.pendEnv.hasStartPoint && tonesNext.pendEnv.startPos < tonesNext.pendEnv.stopPos)
{
tonesNext.currEnv.hasStartPoint = true;
tonesNext.currEnv.startPos = tonesNext.pendEnv.startPos + 32;
}
else if (tonesNow.pendEnv.hasStartPoint)
{
tonesNext.currEnv.hasStartPoint = true;
tonesNext.currEnv.startPos = tonesNow.pendEnv.startPos;
}
else
{
tonesNext.currEnv.hasStartPoint = false;
tonesNext.currEnv.startPos = 0;
}
if (tonesNow.pendEnv.hasStopPoint && tonesNow.pendEnv.stopPos >= tonesNext.currEnv.startPos)
{
tonesNext.currEnv.hasStopPoint = true;
tonesNext.currEnv.stopPos = tonesNow.pendEnv.stopPos;
}
else if (tonesNext.pendEnv.hasStopPoint)
{
tonesNext.currEnv.hasStopPoint = true;
tonesNext.currEnv.stopPos = tonesNext.pendEnv.stopPos + 32;
}
else
{
tonesNext.currEnv.hasStopPoint = false;
tonesNext.currEnv.stopPos = 64;
}
// is the visible part of the envelope non-zero?
bool reg1EnvNonzero = (tonesNow.currEnv.stopPos < 32 ? false : true);
bool reg2EnvNonzero = (tonesNext.currEnv.startPos >= 32 ? false : true);
// synthesize waves for both overlapping regions
if (tonesNow.numWavs > 0 && reg1EnvNonzero)
{
wavesSynth(ctx.wavesInfoPrev, tonesNow, tonesNow.currEnv, ctx.wavesInfoPrev.phaseShift[sb] && (chNum > 0), 128, wavreg1);
}
if (tonesNext.numWavs > 0 && reg2EnvNonzero)
{
wavesSynth(ctx.wavesInfo, tonesNext, tonesNext.currEnv, ctx.wavesInfo.phaseShift[sb] && (chNum > 0), 0, wavreg2);
}
// Hann windowing for non-faded wave signals
if (tonesNow.numWavs > 0 && tonesNext.numWavs > 0 && reg1EnvNonzero && reg2EnvNonzero)
{
vectorFmul(wavreg1, 0, wavreg1, 0, hann_window, 128, 128);
vectorFmul(wavreg2, 0, wavreg2, 0, hann_window, 0, 128);
}
else
{
if (tonesNow.numWavs > 0 && !tonesNow.currEnv.hasStopPoint)
{
vectorFmul(wavreg1, 0, wavreg1, 0, hann_window, 128, 128);
}
if (tonesNext.numWavs > 0 && !tonesNext.currEnv.hasStartPoint)
{
vectorFmul(wavreg2, 0, wavreg2, 0, hann_window, 0, 128);
}
}
// Overlap and add to residual
for (int i = 0; i < 128; i++)
{
@out[outOffset + i] += wavreg1[i] + wavreg2[i];
}
}