internal int celt_decoder_init(int sampling_rate, int channels)
{
int ret;
ret = this.opus_custom_decoder_init(CeltMode.mode48000_960_120, channels);
if (ret != OpusError.OPUS_OK)
{
return(ret);
}
this.downsample = CeltCommon.resampling_factor(sampling_rate);
if (this.downsample == 0)
{
return(OpusError.OPUS_BAD_ARG);
}
else
{
return(OpusError.OPUS_OK);
}
}
internal int celt_decode_with_ec(byte[] data, int data_ptr,
int len, short[] pcm, int pcm_ptr, int frame_size, EntropyCoder dec, int accum)
{
int c, i, N;
int spread_decision;
int bits;
int[][] X;
int[] fine_quant;
int[] pulses;
int[] cap;
int[] offsets;
int[] fine_priority;
int[] tf_res;
byte[] collapse_masks;
int[][] out_syn = new int[2][];
int[] out_syn_ptrs = new int[2];
int[] oldBandE, oldLogE, oldLogE2, backgroundLogE;
int shortBlocks;
int isTransient;
int intra_ener;
int CC = this.channels;
int LM, M;
int start;
int end;
int effEnd;
int codedBands;
int alloc_trim;
int postfilter_pitch;
int postfilter_gain;
int intensity = 0;
int dual_stereo = 0;
int total_bits;
int balance;
int tell;
int dynalloc_logp;
int postfilter_tapset;
int anti_collapse_rsv;
int anti_collapse_on = 0;
int silence;
int C = this.stream_channels;
CeltMode mode; // porting note: pointer
int nbEBands;
int overlap;
short[] eBands;
mode = this.mode;
nbEBands = mode.nbEBands;
overlap = mode.overlap;
eBands = mode.eBands;
start = this.start;
end = this.end;
frame_size *= this.downsample;
oldBandE = this.oldEBands;
oldLogE = this.oldLogE;
oldLogE2 = this.oldLogE2;
backgroundLogE = this.backgroundLogE;
{
for (LM = 0; LM <= mode.maxLM; LM++)
{
if (mode.shortMdctSize << LM == frame_size)
{
break;
}
}
if (LM > mode.maxLM)
{
return(OpusError.OPUS_BAD_ARG);
}
}
M = 1 << LM;
if (len < 0 || len > 1275 || pcm == null)
{
return(OpusError.OPUS_BAD_ARG);
}
N = M * mode.shortMdctSize;
c = 0; do
{
out_syn[c] = this.decode_mem[c];
out_syn_ptrs[c] = CeltConstants.DECODE_BUFFER_SIZE - N;
} while (++c < CC);
effEnd = end;
if (effEnd > mode.effEBands)
{
effEnd = mode.effEBands;
}
if (data == null || len <= 1)
{
this.celt_decode_lost(N, LM);
CeltCommon.deemphasis(out_syn, out_syn_ptrs, pcm, pcm_ptr, N, CC, this.downsample, mode.preemph, this.preemph_memD, accum);
return(frame_size / this.downsample);
}
if (dec == null)
{
// If no entropy decoder was passed into this function, we need to create
// a new one here for local use only. It only exists in this function scope.
dec = new EntropyCoder();
dec.dec_init(data, data_ptr, (uint)len);
}
if (C == 1)
{
for (i = 0; i < nbEBands; i++)
{
oldBandE[i] = Inlines.MAX16(oldBandE[i], oldBandE[nbEBands + i]);
}
}
total_bits = len * 8;
tell = dec.tell();
if (tell >= total_bits)
{
silence = 1;
}
else if (tell == 1)
{
silence = dec.dec_bit_logp(15);
}
else
{
silence = 0;
}
if (silence != 0)
{
/* Pretend we've read all the remaining bits */
tell = len * 8;
dec.nbits_total += tell - dec.tell();
}
postfilter_gain = 0;
postfilter_pitch = 0;
postfilter_tapset = 0;
if (start == 0 && tell + 16 <= total_bits)
{
if (dec.dec_bit_logp(1) != 0)
{
int qg, octave;
octave = (int)dec.dec_uint(6);
postfilter_pitch = (16 << octave) + (int)dec.dec_bits(4 + (uint)octave) - 1;
qg = (int)dec.dec_bits(3);
if (dec.tell() + 2 <= total_bits)
{
postfilter_tapset = dec.dec_icdf(Tables.tapset_icdf, 2);
}
postfilter_gain = ((short)(0.5 + (.09375f) * (((int)1) << (15)))) /*Inlines.QCONST16(.09375f, 15)*/ * (qg + 1);
}
tell = dec.tell();
}
if (LM > 0 && tell + 3 <= total_bits)
{
isTransient = dec.dec_bit_logp(3);
tell = dec.tell();
}
else
{
isTransient = 0;
}
if (isTransient != 0)
{
shortBlocks = M;
}
else
{
shortBlocks = 0;
}
/* Decode the global flags (first symbols in the stream) */
intra_ener = tell + 3 <= total_bits?dec.dec_bit_logp(3) : 0;
/* Get band energies */
QuantizeBands.unquant_coarse_energy(mode, start, end, oldBandE,
intra_ener, dec, C, LM);
tf_res = new int[nbEBands];
CeltCommon.tf_decode(start, end, isTransient, tf_res, LM, dec);
tell = dec.tell();
spread_decision = Spread.SPREAD_NORMAL;
if (tell + 4 <= total_bits)
{
spread_decision = dec.dec_icdf(Tables.spread_icdf, 5);
}
cap = new int[nbEBands];
CeltCommon.init_caps(mode, cap, LM, C);
offsets = new int[nbEBands];
dynalloc_logp = 6;
total_bits <<= EntropyCoder.BITRES;
tell = (int)dec.tell_frac();
for (i = start; i < end; i++)
{
int width, quanta;
int dynalloc_loop_logp;
int boost;
width = C * (eBands[i + 1] - eBands[i]) << LM;
/* quanta is 6 bits, but no more than 1 bit/sample
* and no less than 1/8 bit/sample */
quanta = Inlines.IMIN(width << EntropyCoder.BITRES, Inlines.IMAX(6 << EntropyCoder.BITRES, width));
dynalloc_loop_logp = dynalloc_logp;
boost = 0;
while (tell + (dynalloc_loop_logp << EntropyCoder.BITRES) < total_bits && boost < cap[i])
{
int flag;
flag = dec.dec_bit_logp((uint)dynalloc_loop_logp);
tell = (int)dec.tell_frac();
if (flag == 0)
{
break;
}
boost += quanta;
total_bits -= quanta;
dynalloc_loop_logp = 1;
}
offsets[i] = boost;
/* Making dynalloc more likely */
if (boost > 0)
{
dynalloc_logp = Inlines.IMAX(2, dynalloc_logp - 1);
}
}
fine_quant = new int[nbEBands];
alloc_trim = tell + (6 << EntropyCoder.BITRES) <= total_bits?
dec.dec_icdf(Tables.trim_icdf, 7) : 5;
bits = (((int)len * 8) << EntropyCoder.BITRES) - (int)dec.tell_frac() - 1;
anti_collapse_rsv = isTransient != 0 && LM >= 2 && bits >= ((LM + 2) << EntropyCoder.BITRES) ? (1 << EntropyCoder.BITRES) : 0;
bits -= anti_collapse_rsv;
pulses = new int[nbEBands];
fine_priority = new int[nbEBands];
codedBands = Rate.compute_allocation(mode, start, end, offsets, cap,
alloc_trim, ref intensity, ref dual_stereo, bits, out balance, pulses,
fine_quant, fine_priority, C, LM, dec, 0, 0, 0);
QuantizeBands.unquant_fine_energy(mode, start, end, oldBandE, fine_quant, dec, C);
c = 0;
do
{
Arrays.MemMoveInt(decode_mem[c], N, 0, CeltConstants.DECODE_BUFFER_SIZE - N + overlap / 2);
} while (++c < CC);
/* Decode fixed codebook */
collapse_masks = new byte[C * nbEBands];
X = Arrays.InitTwoDimensionalArray <int>(C, N); /**< Interleaved normalised MDCTs */
Bands.quant_all_bands(0, mode, start, end, X[0], C == 2 ? X[1] : null, collapse_masks,
null, pulses, shortBlocks, spread_decision, dual_stereo, intensity, tf_res,
len * (8 << EntropyCoder.BITRES) - anti_collapse_rsv, balance, dec, LM, codedBands, ref this.rng);
if (anti_collapse_rsv > 0)
{
anti_collapse_on = (int)dec.dec_bits(1);
}
QuantizeBands.unquant_energy_finalise(mode, start, end, oldBandE,
fine_quant, fine_priority, len * 8 - dec.tell(), dec, C);
if (anti_collapse_on != 0)
{
Bands.anti_collapse(mode, X, collapse_masks, LM, C, N,
start, end, oldBandE, oldLogE, oldLogE2, pulses, this.rng);
}
if (silence != 0)
{
for (i = 0; i < C * nbEBands; i++)
{
oldBandE[i] = -((short)(0.5 + (28.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(28.0f, CeltConstants.DB_SHIFT)*/;
}
}
CeltCommon.celt_synthesis(mode, X, out_syn, out_syn_ptrs, oldBandE, start, effEnd,
C, CC, isTransient, LM, this.downsample, silence);
c = 0; do
{
this.postfilter_period = Inlines.IMAX(this.postfilter_period, CeltConstants.COMBFILTER_MINPERIOD);
this.postfilter_period_old = Inlines.IMAX(this.postfilter_period_old, CeltConstants.COMBFILTER_MINPERIOD);
CeltCommon.comb_filter(out_syn[c], out_syn_ptrs[c], out_syn[c], out_syn_ptrs[c], this.postfilter_period_old, this.postfilter_period, mode.shortMdctSize,
this.postfilter_gain_old, this.postfilter_gain, this.postfilter_tapset_old, this.postfilter_tapset,
mode.window, overlap);
if (LM != 0)
{
CeltCommon.comb_filter(
out_syn[c], out_syn_ptrs[c] + (mode.shortMdctSize),
out_syn[c], out_syn_ptrs[c] + (mode.shortMdctSize),
this.postfilter_period, postfilter_pitch, N - mode.shortMdctSize,
this.postfilter_gain, postfilter_gain, this.postfilter_tapset, postfilter_tapset,
mode.window, overlap);
}
} while (++c < CC);
this.postfilter_period_old = this.postfilter_period;
this.postfilter_gain_old = this.postfilter_gain;
this.postfilter_tapset_old = this.postfilter_tapset;
this.postfilter_period = postfilter_pitch;
this.postfilter_gain = postfilter_gain;
this.postfilter_tapset = postfilter_tapset;
if (LM != 0)
{
this.postfilter_period_old = this.postfilter_period;
this.postfilter_gain_old = this.postfilter_gain;
this.postfilter_tapset_old = this.postfilter_tapset;
}
if (C == 1)
{
Array.Copy(oldBandE, 0, oldBandE, nbEBands, nbEBands);
}
/* In case start or end were to change */
if (isTransient == 0)
{
int max_background_increase;
Array.Copy(oldLogE, oldLogE2, 2 * nbEBands);
Array.Copy(oldBandE, oldLogE, 2 * nbEBands);
/* In normal circumstances, we only allow the noise floor to increase by
* up to 2.4 dB/second, but when we're in DTX, we allow up to 6 dB
* increase for each update.*/
if (this.loss_count < 10)
{
max_background_increase = M * ((short)(0.5 + (0.001f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(0.001f, CeltConstants.DB_SHIFT)*/;
}
else
{
max_background_increase = ((short)(0.5 + (1.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(1.0f, CeltConstants.DB_SHIFT)*/;
}
for (i = 0; i < 2 * nbEBands; i++)
{
backgroundLogE[i] = Inlines.MIN16(backgroundLogE[i] + max_background_increase, oldBandE[i]);
}
}
else
{
for (i = 0; i < 2 * nbEBands; i++)
{
oldLogE[i] = Inlines.MIN16(oldLogE[i], oldBandE[i]);
}
}
c = 0; do
{
for (i = 0; i < start; i++)
{
oldBandE[c * nbEBands + i] = 0;
oldLogE[c * nbEBands + i] = oldLogE2[c * nbEBands + i] = -((short)(0.5 + (28.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(28.0f, CeltConstants.DB_SHIFT)*/;
}
for (i = end; i < nbEBands; i++)
{
oldBandE[c * nbEBands + i] = 0;
oldLogE[c * nbEBands + i] = oldLogE2[c * nbEBands + i] = -((short)(0.5 + (28.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(28.0f, CeltConstants.DB_SHIFT)*/;
}
} while (++c < 2);
this.rng = dec.rng;
CeltCommon.deemphasis(out_syn, out_syn_ptrs, pcm, pcm_ptr, N, CC, this.downsample, mode.preemph, this.preemph_memD, accum);
this.loss_count = 0;
if (dec.tell() > 8 * len)
{
return(OpusError.OPUS_INTERNAL_ERROR);
}
if (dec.get_error() != 0)
{
this.error = 1;
}
return(frame_size / this.downsample);
}
internal void celt_decode_lost(int N, int LM)
{
int c;
int i;
int C = this.channels;
int[][] out_syn = new int[2][];
int[] out_syn_ptrs = new int[2];
CeltMode mode;
int nbEBands;
int overlap;
int noise_based;
short[] eBands;
mode = this.mode;
nbEBands = mode.nbEBands;
overlap = mode.overlap;
eBands = mode.eBands;
c = 0; do
{
out_syn[c] = this.decode_mem[c];
out_syn_ptrs[c] = CeltConstants.DECODE_BUFFER_SIZE - N;
} while (++c < C);
noise_based = (loss_count >= 5 || start != 0) ? 1 : 0;
if (noise_based != 0)
{
/* Noise-based PLC/CNG */
int[][] X;
uint seed;
int end;
int effEnd;
int decay;
end = this.end;
effEnd = Inlines.IMAX(start, Inlines.IMIN(end, mode.effEBands));
X = Arrays.InitTwoDimensionalArray <int>(C, N); /**< Interleaved normalised MDCTs */
/* Energy decay */
decay = loss_count == 0 ? ((short)(0.5 + (1.5f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(1.5f, CeltConstants.DB_SHIFT)*/ : ((short)(0.5 + (0.5f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(0.5f, CeltConstants.DB_SHIFT)*/;
c = 0; do
{
for (i = start; i < end; i++)
{
this.oldEBands[c * nbEBands + i] = Inlines.MAX16(backgroundLogE[c * nbEBands + i], this.oldEBands[c * nbEBands + i] - decay);
}
} while (++c < C);
seed = this.rng;
for (c = 0; c < C; c++)
{
for (i = start; i < effEnd; i++)
{
int j;
int boffs;
int blen;
boffs = (eBands[i] << LM);
blen = (eBands[i + 1] - eBands[i]) << LM;
for (j = 0; j < blen; j++)
{
seed = Bands.celt_lcg_rand(seed);
X[c][boffs + j] = (unchecked ((int)seed) >> 20);
}
VQ.renormalise_vector(X[c], 0, blen, CeltConstants.Q15ONE);
}
}
this.rng = seed;
c = 0;
do
{
Arrays.MemMoveInt(this.decode_mem[c], N, 0, CeltConstants.DECODE_BUFFER_SIZE - N + (overlap >> 1));
} while (++c < C);
CeltCommon.celt_synthesis(mode, X, out_syn, out_syn_ptrs, this.oldEBands, start, effEnd, C, C, 0, LM, this.downsample, 0);
}
else
{
/* Pitch-based PLC */
int[] window;
int fade = CeltConstants.Q15ONE;
int pitch_index;
int[] etmp;
int[] exc;
if (loss_count == 0)
{
this.last_pitch_index = pitch_index = CeltCommon.celt_plc_pitch_search(this.decode_mem, C);
}
else
{
pitch_index = this.last_pitch_index;
fade = ((short)(0.5 + (.8f) * (((int)1) << (15)))) /*Inlines.QCONST16(.8f, 15)*/;
}
etmp = new int[overlap];
exc = new int[CeltConstants.MAX_PERIOD];
window = mode.window;
c = 0; do
{
int decay;
int attenuation;
int S1 = 0;
int[] buf;
int extrapolation_offset;
int extrapolation_len;
int exc_length;
int j;
buf = this.decode_mem[c];
for (i = 0; i < CeltConstants.MAX_PERIOD; i++)
{
exc[i] = Inlines.ROUND16(buf[CeltConstants.DECODE_BUFFER_SIZE - CeltConstants.MAX_PERIOD + i], CeltConstants.SIG_SHIFT);
}
if (loss_count == 0)
{
int[] ac = new int[CeltConstants.LPC_ORDER + 1];
/* Compute LPC coefficients for the last MAX_PERIOD samples before
* the first loss so we can work in the excitation-filter domain. */
Autocorrelation._celt_autocorr(exc, ac, window, overlap,
CeltConstants.LPC_ORDER, CeltConstants.MAX_PERIOD);
/* Add a noise floor of -40 dB. */
ac[0] += Inlines.SHR32(ac[0], 13);
/* Use lag windowing to stabilize the Levinson-Durbin recursion. */
for (i = 1; i <= CeltConstants.LPC_ORDER; i++)
{
/*ac[i] *= exp(-.5*(2*M_PI*.002*i)*(2*M_PI*.002*i));*/
ac[i] -= Inlines.MULT16_32_Q15(2 * i * i, ac[i]);
}
CeltLPC.celt_lpc(this.lpc[c], ac, CeltConstants.LPC_ORDER);
}
/* We want the excitation for 2 pitch periods in order to look for a
* decaying signal, but we can't get more than MAX_PERIOD. */
exc_length = Inlines.IMIN(2 * pitch_index, CeltConstants.MAX_PERIOD);
/* Initialize the LPC history with the samples just before the start
* of the region for which we're computing the excitation. */
{
int[] lpc_mem = new int[CeltConstants.LPC_ORDER];
for (i = 0; i < CeltConstants.LPC_ORDER; i++)
{
lpc_mem[i] =
Inlines.ROUND16(buf[CeltConstants.DECODE_BUFFER_SIZE - exc_length - 1 - i], CeltConstants.SIG_SHIFT);
}
/* Compute the excitation for exc_length samples before the loss. */
Kernels.celt_fir(exc, (CeltConstants.MAX_PERIOD - exc_length), this.lpc[c], 0,
exc, (CeltConstants.MAX_PERIOD - exc_length), exc_length, CeltConstants.LPC_ORDER, lpc_mem);
}
/* Check if the waveform is decaying, and if so how fast.
* We do this to avoid adding energy when concealing in a segment
* with decaying energy. */
{
int E1 = 1, E2 = 1;
int decay_length;
int shift = Inlines.IMAX(0, 2 * Inlines.celt_zlog2(Inlines.celt_maxabs16(exc, (CeltConstants.MAX_PERIOD - exc_length), exc_length)) - 20);
decay_length = exc_length >> 1;
for (i = 0; i < decay_length; i++)
{
int e;
e = exc[CeltConstants.MAX_PERIOD - decay_length + i];
E1 += Inlines.SHR32(Inlines.MULT16_16(e, e), shift);
e = exc[CeltConstants.MAX_PERIOD - 2 * decay_length + i];
E2 += Inlines.SHR32(Inlines.MULT16_16(e, e), shift);
}
E1 = Inlines.MIN32(E1, E2);
decay = Inlines.celt_sqrt(Inlines.frac_div32(Inlines.SHR32(E1, 1), E2));
}
/* Move the decoder memory one frame to the left to give us room to
* add the data for the new frame. We ignore the overlap that extends
* past the end of the buffer, because we aren't going to use it. */
Arrays.MemMoveInt(buf, N, 0, CeltConstants.DECODE_BUFFER_SIZE - N);
/* Extrapolate from the end of the excitation with a period of
* "pitch_index", scaling down each period by an additional factor of
* "decay". */
extrapolation_offset = CeltConstants.MAX_PERIOD - pitch_index;
/* We need to extrapolate enough samples to cover a complete MDCT
* window (including overlap/2 samples on both sides). */
extrapolation_len = N + overlap;
/* We also apply fading if this is not the first loss. */
attenuation = Inlines.MULT16_16_Q15(fade, decay);
for (i = j = 0; i < extrapolation_len; i++, j++)
{
int tmp;
if (j >= pitch_index)
{
j -= pitch_index;
attenuation = Inlines.MULT16_16_Q15(attenuation, decay);
}
buf[CeltConstants.DECODE_BUFFER_SIZE - N + i] =
Inlines.SHL32((Inlines.MULT16_16_Q15(attenuation,
exc[extrapolation_offset + j])), CeltConstants.SIG_SHIFT);
/* Compute the energy of the previously decoded signal whose
* excitation we're copying. */
tmp = Inlines.ROUND16(
buf[CeltConstants.DECODE_BUFFER_SIZE - CeltConstants.MAX_PERIOD - N + extrapolation_offset + j],
CeltConstants.SIG_SHIFT);
S1 += Inlines.SHR32(Inlines.MULT16_16(tmp, tmp), 8);
}
{
int[] lpc_mem = new int[CeltConstants.LPC_ORDER];
/* Copy the last decoded samples (prior to the overlap region) to
* synthesis filter memory so we can have a continuous signal. */
for (i = 0; i < CeltConstants.LPC_ORDER; i++)
{
lpc_mem[i] = Inlines.ROUND16(buf[CeltConstants.DECODE_BUFFER_SIZE - N - 1 - i], CeltConstants.SIG_SHIFT);
}
/* Apply the synthesis filter to convert the excitation back into
* the signal domain. */
CeltLPC.celt_iir(buf, CeltConstants.DECODE_BUFFER_SIZE - N, this.lpc[c],
buf, CeltConstants.DECODE_BUFFER_SIZE - N, extrapolation_len, CeltConstants.LPC_ORDER,
lpc_mem);
}
/* Check if the synthesis energy is higher than expected, which can
* happen with the signal changes during our window. If so,
* attenuate. */
{
int S2 = 0;
for (i = 0; i < extrapolation_len; i++)
{
int tmp = Inlines.ROUND16(buf[CeltConstants.DECODE_BUFFER_SIZE - N + i], CeltConstants.SIG_SHIFT);
S2 += Inlines.SHR32(Inlines.MULT16_16(tmp, tmp), 8);
}
/* This checks for an "explosion" in the synthesis. */
if (!(S1 > Inlines.SHR32(S2, 2)))
{
for (i = 0; i < extrapolation_len; i++)
{
buf[CeltConstants.DECODE_BUFFER_SIZE - N + i] = 0;
}
}
else if (S1 < S2)
{
int ratio = Inlines.celt_sqrt(Inlines.frac_div32(Inlines.SHR32(S1, 1) + 1, S2 + 1));
for (i = 0; i < overlap; i++)
{
int tmp_g = CeltConstants.Q15ONE
- Inlines.MULT16_16_Q15(window[i], CeltConstants.Q15ONE - ratio);
buf[CeltConstants.DECODE_BUFFER_SIZE - N + i] =
Inlines.MULT16_32_Q15(tmp_g, buf[CeltConstants.DECODE_BUFFER_SIZE - N + i]);
}
for (i = overlap; i < extrapolation_len; i++)
{
buf[CeltConstants.DECODE_BUFFER_SIZE - N + i] =
Inlines.MULT16_32_Q15(ratio, buf[CeltConstants.DECODE_BUFFER_SIZE - N + i]);
}
}
}
/* Apply the pre-filter to the MDCT overlap for the next frame because
* the post-filter will be re-applied in the decoder after the MDCT
* overlap. */
CeltCommon.comb_filter(etmp, 0, buf, CeltConstants.DECODE_BUFFER_SIZE,
this.postfilter_period, this.postfilter_period, overlap,
-this.postfilter_gain, -this.postfilter_gain,
this.postfilter_tapset, this.postfilter_tapset, null, 0);
/* Simulate TDAC on the concealed audio so that it blends with the
* MDCT of the next frame. */
for (i = 0; i < overlap / 2; i++)
{
buf[CeltConstants.DECODE_BUFFER_SIZE + i] =
Inlines.MULT16_32_Q15(window[i], etmp[overlap - 1 - i])
+ Inlines.MULT16_32_Q15(window[overlap - i - 1], etmp[i]);
}
} while (++c < C);
}
this.loss_count = loss_count + 1;
}
// fixme: test the perf of this alternate implementation
//int logSum(int a, int b)
//{
// return log2(pow(4, a) + pow(4, b)) / 2;
//}
internal static void surround_analysis <T>(CeltMode celt_mode, T[] pcm, int pcm_ptr,
int[] bandLogE, int[] mem, int[] preemph_mem,
int len, int overlap, int channels, int rate, opus_copy_channel_in_func <T> copy_channel_in
)
{
int c;
int i;
int LM;
int[] pos = { 0, 0, 0, 0, 0, 0, 0, 0 };
int upsample;
int frame_size;
int channel_offset;
int[][] bandE = Arrays.InitTwoDimensionalArray <int>(1, 21);
int[][] maskLogE = Arrays.InitTwoDimensionalArray <int>(3, 21);
int[] input;
short[] x;
int[][] freq;
upsample = CeltCommon.resampling_factor(rate);
frame_size = len * upsample;
for (LM = 0; LM < celt_mode.maxLM; LM++)
{
if (celt_mode.shortMdctSize << LM == frame_size)
{
break;
}
}
input = new int[frame_size + overlap];
x = new short[len];
freq = Arrays.InitTwoDimensionalArray <int>(1, frame_size);
channel_pos(channels, pos);
for (c = 0; c < 3; c++)
{
for (i = 0; i < 21; i++)
{
maskLogE[c][i] = -((short)(0.5 + (28.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(28.0f, CeltConstants.DB_SHIFT)*/;
}
}
for (c = 0; c < channels; c++)
{
Array.Copy(mem, c * overlap, input, 0, overlap);
copy_channel_in(x, 0, 1, pcm, pcm_ptr, channels, c, len);
BoxedValueInt boxed_preemph = new BoxedValueInt(preemph_mem[c]);
CeltCommon.celt_preemphasis(x, input, overlap, frame_size, 1, upsample, celt_mode.preemph, boxed_preemph, 0);
preemph_mem[c] = boxed_preemph.Val;
MDCT.clt_mdct_forward(
celt_mode.mdct,
input,
0,
freq[0],
0,
celt_mode.window,
overlap,
celt_mode.maxLM - LM,
1);
if (upsample != 1)
{
int bound = len;
for (i = 0; i < bound; i++)
{
freq[0][i] *= upsample;
}
for (; i < frame_size; i++)
{
freq[0][i] = 0;
}
}
Bands.compute_band_energies(celt_mode, freq, bandE, 21, 1, LM);
QuantizeBands.amp2Log2(celt_mode, 21, 21, bandE[0], bandLogE, 21 * c, 1);
/* Apply spreading function with -6 dB/band going up and -12 dB/band going down. */
for (i = 1; i < 21; i++)
{
bandLogE[21 * c + i] = Inlines.MAX16(bandLogE[21 * c + i], bandLogE[21 * c + i - 1] - ((short)(0.5 + (1.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(1.0f, CeltConstants.DB_SHIFT)*/);
}
for (i = 19; i >= 0; i--)
{
bandLogE[21 * c + i] = Inlines.MAX16(bandLogE[21 * c + i], bandLogE[21 * c + i + 1] - ((short)(0.5 + (2.0f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(2.0f, CeltConstants.DB_SHIFT)*/);
}
if (pos[c] == 1)
{
for (i = 0; i < 21; i++)
{
maskLogE[0][i] = logSum(maskLogE[0][i], bandLogE[21 * c + i]);
}
}
else if (pos[c] == 3)
{
for (i = 0; i < 21; i++)
{
maskLogE[2][i] = logSum(maskLogE[2][i], bandLogE[21 * c + i]);
}
}
else if (pos[c] == 2)
{
for (i = 0; i < 21; i++)
{
maskLogE[0][i] = logSum(maskLogE[0][i], bandLogE[21 * c + i] - ((short)(0.5 + (.5f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(.5f, CeltConstants.DB_SHIFT)*/);
maskLogE[2][i] = logSum(maskLogE[2][i], bandLogE[21 * c + i] - ((short)(0.5 + (.5f) * (((int)1) << (CeltConstants.DB_SHIFT)))) /*Inlines.QCONST16(.5f, CeltConstants.DB_SHIFT)*/);
}
}
Array.Copy(input, frame_size, mem, c * overlap, overlap);
}
for (i = 0; i < 21; i++)
{
maskLogE[1][i] = Inlines.MIN32(maskLogE[0][i], maskLogE[2][i]);
}
channel_offset = Inlines.HALF16(Inlines.celt_log2(((int)(0.5 + (2.0f) * (((int)1) << (14)))) /*Inlines.QCONST32(2.0f, 14)*/ / (channels - 1)));
for (c = 0; c < 3; c++)
{
for (i = 0; i < 21; i++)
{
maskLogE[c][i] += channel_offset;
}
}
for (c = 0; c < channels; c++)
{
int[] mask;
if (pos[c] != 0)
{
mask = maskLogE[pos[c] - 1];
for (i = 0; i < 21; i++)
{
bandLogE[21 * c + i] = bandLogE[21 * c + i] - mask[i];
}
}
else
{
for (i = 0; i < 21; i++)
{
bandLogE[21 * c + i] = 0;
}
}
}
}