public SOXResampler(AudioPCMConfig inputPCM, AudioPCMConfig outputPCM, SOXResamplerConfig config)
{
this.inputPCM = inputPCM;
this.outputPCM = outputPCM;
if (inputPCM.ChannelCount != outputPCM.ChannelCount)
throw new NotSupportedException();
if (outputPCM.SampleRate == inputPCM.SampleRate * 4 && config.Quality >= SOXResamplerQuality.Medium)
{
this.rate = new rate_t[inputPCM.ChannelCount];
this.shared = new rate_shared_t();
this.rateUp2 = new rate_t[inputPCM.ChannelCount];
this.sharedUp2 = new rate_shared_t();
for (int i = 0; i < inputPCM.ChannelCount; i++)
{
rateUp2[i] = new rate_t(inputPCM.SampleRate, inputPCM.SampleRate * 2, sharedUp2, 0.5,
config.Quality, -1, config.Phase, config.Bandwidth, config.AllowAliasing);
rate[i] = new rate_t(inputPCM.SampleRate * 2, inputPCM.SampleRate * 4, shared, 0.5,
config.Quality, -1, 50, 90, true);
}
}
else
{
this.rate = new rate_t[inputPCM.ChannelCount];
this.shared = new rate_shared_t();
for (int i = 0; i < inputPCM.ChannelCount; i++)
{
rate[i] = new rate_t(inputPCM.SampleRate, outputPCM.SampleRate, shared, (double)inputPCM.SampleRate / outputPCM.SampleRate,
config.Quality, -1, config.Phase, config.Bandwidth, config.AllowAliasing);
}
}
}
static void half_band_filter_init(rate_shared_t p, int which,
int num_taps, double[] h, double Fp, double att, int multiplier,
double phase, bool allow_aliasing)
{
dft_filter_t f = p.half_band[which];
int dft_length, i;
if (f.num_taps != 0)
{
return;
}
if (h != null)
{
dft_length = lsx_set_dft_length(num_taps);
f.coefs = new double[dft_length];
for (i = 0; i < num_taps; ++i)
{
f.coefs[(i + dft_length - num_taps + 1) & (dft_length - 1)]
= h[Math.Abs(num_taps / 2 - i)] / dft_length * 2 * multiplier;
}
f.post_peak = num_taps / 2;
}
else
{
h = lsx_design_lpf(Fp, 1.0, 2.0, allow_aliasing, att, ref num_taps, 0);
if (phase != 50)
{
lsx_fir_to_phase(ref h, ref num_taps, ref f.post_peak, phase, p.info);
}
else
{
f.post_peak = num_taps / 2;
}
dft_length = lsx_set_dft_length(num_taps);
f.coefs = new double[dft_length];
for (i = 0; i < num_taps; ++i)
{
f.coefs[(i + dft_length - num_taps + 1) & (dft_length - 1)]
= h[i] / dft_length * 2 * multiplier;
}
}
//assert(num_taps & 1);
f.num_taps = num_taps;
f.dft_length = dft_length;
//lsx_debug("fir_len=%i dft_length=%i Fp=%g att=%g mult=%i",
//num_taps, dft_length, Fp, att, multiplier);
SOXFft.safe_rdft(dft_length, 1, f.coefs, p.info);
}
internal stage_t(rate_shared_t shared)
{
this.shared = shared;
}
public rate_t(int in_samplerate, int out_samplerate, rate_shared_t shared, double factor,
SOXResamplerQuality quality, int interp_order, double phase, double bandwidth,
bool allow_aliasing)
{
this.in_samplerate = in_samplerate;
this.out_samplerate = out_samplerate;
int i, mult, divisor = 1;
//assert(factor > 0);
this.factor = factor;
if (quality < SOXResamplerQuality.Quick || quality > SOXResamplerQuality.Very)
{
quality = SOXResamplerQuality.High;
}
if (quality != SOXResamplerQuality.Quick)
{
const int max_divisor = 2048; /* Keep coef table size ~< 500kb */
const double epsilon = 4 / MULT32; /* Scaled to half this at max_divisor */
this.upsample = this.factor < 1;
this.level = 0;
for (int fi = (int)factor >> 1; fi != 0; fi >>= 1)
{
++this.level;/* log base 2 */
}
factor /= 1 << (this.level + (this.upsample ? 0 : 1));
for (i = 2; i <= max_divisor && divisor == 1; ++i)
{
double try_d = factor * i;
int itry = (int)(try_d + .5);
if (Math.Abs(itry - try_d) < itry * epsilon * (1 - (.5 / max_divisor) * i))
{
if (itry == i) /* Rounded to 1:1? */
{
factor = 1;
divisor = 2;
this.upsample = false;
}
else
{
factor = itry;
divisor = i;
}
}
}
}
this.stages = new stage_t[this.level + 4]; // offset by 1!!! + 3?
for (i = 0; i < this.level + 4; ++i)
{
this.stages[i] = new stage_t(shared);
}
this.pre_stage = this.stages[0];
this.last_stage = this.stages[this.level + 1];
this.post_stage = this.stages[this.level + 2];
this.last_stage.step = (long)(factor * MULT32 + .5);
this.last_stage.out_in_ratio = MULT32 * divisor / this.last_stage.step;
//if (divisor != 1)
// assert(!last_stage.step.parts.fraction);
//else if (quality != Quick)
// assert(!last_stage.step.parts.integer);
//lsx_debug("i/o=%g; %.9g:%i @ level %i", this.factor, factor, divisor, this.level);
mult = 1 + (this.upsample ? 1 : 0); /* Compensate for zero-stuffing in double_sample */
this.input_stage_num = this.upsample ? 0 : 1;
this.output_stage_num = this.level + 1;
if (quality == SOXResamplerQuality.Quick)
{
++this.output_stage_num;
last_stage.fn = cubic_spline;
last_stage.pre_post = Math.Max(3, (int)(last_stage.step >> 32));
last_stage.preload = last_stage.pre = 1;
}
else if (last_stage.out_in_ratio != 2 || (this.upsample && quality == SOXResamplerQuality.Low))
{
int n = (this.upsample ? 4 : 0) + range_limit((int)quality, (int)SOXResamplerQuality.Medium, (int)SOXResamplerQuality.Very) - (int)SOXResamplerQuality.Medium;
if (interp_order < 0)
{
interp_order = quality > SOXResamplerQuality.High ? 1 : 0;
}
interp_order = divisor == 1 ? 1 + interp_order : 0;
last_stage.divisor = divisor;
this.output_stage_num += 2;
if (this.upsample && quality == SOXResamplerQuality.Low)
{
mult = 1;
++this.input_stage_num;
--this.output_stage_num;
--n;
}
poly_fir_t f = poly_firs[n];
poly_fir1_t f1 = f.interp[interp_order];
if (last_stage.shared.poly_fir_coefs == null)
{
int num_taps = 0, phases = divisor == 1 ? (1 << f1.phase_bits) : divisor;
double[] coefs = lsx_design_lpf(
f.pass, f.stop, 1.0, false, f.att, ref num_taps, phases);
//assert(num_taps == f->num_coefs * phases - 1);
last_stage.shared.poly_fir_coefs =
prepare_coefs(coefs, f.num_coefs, phases, interp_order, mult);
//lsx_debug("fir_len=%i phases=%i coef_interp=%i mult=%i size=%s",
// f->num_coefs, phases, interp_order, mult,
// lsx_sigfigs3((num_taps +1.) * (interp_order + 1) * sizeof(double)));
//free(coefs);
}
last_stage.fn = f1.fn;
last_stage.pre_post = f.num_coefs - 1;
last_stage.pre = 0;
last_stage.preload = last_stage.pre_post >> 1;
mult = 1;
}
if (quality > SOXResamplerQuality.Low)
{
// typedef struct {int len; double const * h; double bw, a;} filter_t;
// static filter_t const filters[] = {
// {2 * array_length(half_fir_coefs_low) - 1, half_fir_coefs_low, 0,0},
// {0, NULL, .931, 110}, {0, NULL, .931, 125}, {0, NULL, .931, 170}};
// filter_t const * f = &filters[quality - Low];
int[] fa = new int[] { 0, 110, 125, 170 };
double[] fbw = new double[] { 0.0, 0.931, 0.931, 0.931 };
double a = fa[quality - SOXResamplerQuality.Low];
double att = allow_aliasing ? (34.0 / 33) * a : a; /* negate att degrade */
double bw = bandwidth != 0 ? 1 - (1 - bandwidth / 100) / LSX_TO_3dB : fbw[quality - SOXResamplerQuality.Low];
double min = 1 - (allow_aliasing ? LSX_MAX_TBW0A : LSX_MAX_TBW0) / 100;
// assert((size_t)(quality - Low) < array_length(filters));
half_band_filter_init(shared, this.upsample ? 1 : 0, 0, null, bw, att, mult, phase, allow_aliasing);
if (this.upsample)
{
pre_stage.fn = double_sample; /* Finish off setting up pre-stage */
pre_stage.preload = shared.half_band[1].post_peak >> 1;
/* Start setting up post-stage; TODO don't use dft for short filters */
if ((1 - this.factor) / (1 - bw) > 2)
{
half_band_filter_init(shared, 0, 0, null, Math.Max(this.factor, min), att, 1, phase, allow_aliasing);
}
else
{
shared.half_band[0] = shared.half_band[1];
}
}
else if (this.level > 0 && this.output_stage_num > this.level)
{
double pass = bw * divisor / factor / 2;
if ((1 - pass) / (1 - bw) > 2)
{
half_band_filter_init(shared, 1, 0, null, Math.Max(pass, min), att, 1, phase, allow_aliasing);
}
}
post_stage.fn = half_sample;
post_stage.preload = shared.half_band[0].post_peak;
}
else if (quality == SOXResamplerQuality.Low && !this.upsample)
{ /* dft is slower here, so */
post_stage.fn = half_sample_low; /* use normal convolution */
post_stage.pre_post = 2 * (half_fir_coefs_low.Length - 1);
post_stage.preload = post_stage.pre = post_stage.pre_post >> 1;
}
if (this.level > 0)
{
stage_t s = this.stages[this.level];
if (shared.half_band[1].num_taps != 0)
{
s.fn = half_sample;
s.preload = shared.half_band[1].post_peak;
s.which = 1;
}
else
{
//*s = post_stage
this.stages[this.level] = post_stage;
// ?????????
this.stages[this.level + 2] = s;
}
}
for (i = this.input_stage_num; i <= this.output_stage_num; ++i)
{
stage_t s = this.stages[i];
if (i > 0 && i < this.level)
{
s.fn = half_sample_25;
s.pre_post = 2 * (half_fir_coefs_25.Length - 1);
s.preload = s.pre = s.pre_post >> 1;
}
s.fifo = new fifo_t(sizeof(double));
s.fifo.reserve(s.preload);
// memset(fifo_reserve(&s->fifo, s->preload), 0, sizeof(double)*s->preload);
// if (i < this.output_stage_num)
// lsx_debug("stage=%-3ipre_post=%-3ipre=%-3ipreload=%i",
// i, s->pre_post, s->pre, s->preload);
}
}
internal stage_t(rate_shared_t shared)
{
this.shared = shared;
}
public rate_t(int in_samplerate, int out_samplerate, rate_shared_t shared, double factor,
SOXResamplerQuality quality, int interp_order, double phase, double bandwidth,
bool allow_aliasing)
{
this.in_samplerate = in_samplerate;
this.out_samplerate = out_samplerate;
int i, mult, divisor = 1;
//assert(factor > 0);
this.factor = factor;
if (quality < SOXResamplerQuality.Quick || quality > SOXResamplerQuality.Very)
quality = SOXResamplerQuality.High;
if (quality != SOXResamplerQuality.Quick)
{
const int max_divisor = 2048; /* Keep coef table size ~< 500kb */
const double epsilon = 4 / MULT32; /* Scaled to half this at max_divisor */
this.upsample = this.factor < 1;
this.level = 0;
for (int fi = (int)factor >> 1; fi != 0; fi >>= 1)
++this.level;/* log base 2 */
factor /= 1 << (this.level + (this.upsample ? 0 : 1));
for (i = 2; i <= max_divisor && divisor == 1; ++i)
{
double try_d = factor * i;
int itry = (int)(try_d + .5);
if (Math.Abs(itry - try_d) < itry * epsilon * (1 - (.5 / max_divisor) * i))
{
if (itry == i) /* Rounded to 1:1? */
{
factor = 1;
divisor = 2;
this.upsample = false;
}
else
{
factor = itry;
divisor = i;
}
}
}
}
this.stages = new stage_t[this.level + 4]; // offset by 1!!! + 3?
for (i = 0; i < this.level + 4; ++i)
this.stages[i] = new stage_t(shared);
this.pre_stage = this.stages[0];
this.last_stage = this.stages[this.level + 1];
this.post_stage = this.stages[this.level + 2];
this.last_stage.step = (long)(factor * MULT32 + .5);
this.last_stage.out_in_ratio = MULT32 * divisor / this.last_stage.step;
//if (divisor != 1)
// assert(!last_stage.step.parts.fraction);
//else if (quality != Quick)
// assert(!last_stage.step.parts.integer);
//lsx_debug("i/o=%g; %.9g:%i @ level %i", this.factor, factor, divisor, this.level);
mult = 1 + (this.upsample ? 1 : 0); /* Compensate for zero-stuffing in double_sample */
this.input_stage_num = this.upsample ? 0 : 1;
this.output_stage_num = this.level + 1;
if (quality == SOXResamplerQuality.Quick)
{
++this.output_stage_num;
last_stage.fn = cubic_spline;
last_stage.pre_post = Math.Max(3, (int)(last_stage.step >> 32));
last_stage.preload = last_stage.pre = 1;
}
else if (last_stage.out_in_ratio != 2 || (this.upsample && quality == SOXResamplerQuality.Low))
{
int n = (this.upsample ? 4 : 0) + range_limit((int)quality, (int)SOXResamplerQuality.Medium, (int)SOXResamplerQuality.Very) - (int)SOXResamplerQuality.Medium;
if (interp_order < 0)
interp_order = quality > SOXResamplerQuality.High ? 1 : 0;
interp_order = divisor == 1 ? 1 + interp_order : 0;
last_stage.divisor = divisor;
this.output_stage_num += 2;
if (this.upsample && quality == SOXResamplerQuality.Low)
{
mult = 1;
++this.input_stage_num;
--this.output_stage_num;
--n;
}
poly_fir_t f = poly_firs[n];
poly_fir1_t f1 = f.interp[interp_order];
if (last_stage.shared.poly_fir_coefs == null)
{
int num_taps = 0, phases = divisor == 1 ? (1 << f1.phase_bits) : divisor;
double[] coefs = lsx_design_lpf(
f.pass, f.stop, 1.0, false, f.att, ref num_taps, phases);
//assert(num_taps == f->num_coefs * phases - 1);
last_stage.shared.poly_fir_coefs =
prepare_coefs(coefs, f.num_coefs, phases, interp_order, mult);
//lsx_debug("fir_len=%i phases=%i coef_interp=%i mult=%i size=%s",
// f->num_coefs, phases, interp_order, mult,
// lsx_sigfigs3((num_taps +1.) * (interp_order + 1) * sizeof(double)));
//free(coefs);
}
last_stage.fn = f1.fn;
last_stage.pre_post = f.num_coefs - 1;
last_stage.pre = 0;
last_stage.preload = last_stage.pre_post >> 1;
mult = 1;
}
if (quality > SOXResamplerQuality.Low)
{
// typedef struct {int len; double const * h; double bw, a;} filter_t;
// static filter_t const filters[] = {
// {2 * array_length(half_fir_coefs_low) - 1, half_fir_coefs_low, 0,0},
// {0, NULL, .931, 110}, {0, NULL, .931, 125}, {0, NULL, .931, 170}};
// filter_t const * f = &filters[quality - Low];
int[] fa = new int[] { 0, 110, 125, 170 };
double[] fbw = new double[] { 0.0, 0.931, 0.931, 0.931 };
double a = fa[quality - SOXResamplerQuality.Low];
double att = allow_aliasing ? (34.0 / 33) * a : a; /* negate att degrade */
double bw = bandwidth != 0 ? 1 - (1 - bandwidth / 100) / LSX_TO_3dB : fbw[quality - SOXResamplerQuality.Low];
double min = 1 - (allow_aliasing ? LSX_MAX_TBW0A : LSX_MAX_TBW0) / 100;
// assert((size_t)(quality - Low) < array_length(filters));
half_band_filter_init(shared, this.upsample ? 1 : 0, 0, null, bw, att, mult, phase, allow_aliasing);
if (this.upsample)
{
pre_stage.fn = double_sample; /* Finish off setting up pre-stage */
pre_stage.preload = shared.half_band[1].post_peak >> 1;
/* Start setting up post-stage; TODO don't use dft for short filters */
if ((1 - this.factor) / (1 - bw) > 2)
half_band_filter_init(shared, 0, 0, null, Math.Max(this.factor, min), att, 1, phase, allow_aliasing);
else shared.half_band[0] = shared.half_band[1];
}
else if (this.level > 0 && this.output_stage_num > this.level)
{
double pass = bw * divisor / factor / 2;
if ((1 - pass) / (1 - bw) > 2)
half_band_filter_init(shared, 1, 0, null, Math.Max(pass, min), att, 1, phase, allow_aliasing);
}
post_stage.fn = half_sample;
post_stage.preload = shared.half_band[0].post_peak;
}
else if (quality == SOXResamplerQuality.Low && !this.upsample)
{ /* dft is slower here, so */
post_stage.fn = half_sample_low; /* use normal convolution */
post_stage.pre_post = 2 * (half_fir_coefs_low.Length - 1);
post_stage.preload = post_stage.pre = post_stage.pre_post >> 1;
}
if (this.level > 0)
{
stage_t s = this.stages[this.level];
if (shared.half_band[1].num_taps != 0)
{
s.fn = half_sample;
s.preload = shared.half_band[1].post_peak;
s.which = 1;
}
else
{
//*s = post_stage
this.stages[this.level] = post_stage;
// ?????????
this.stages[this.level + 2] = s;
}
}
for (i = this.input_stage_num; i <= this.output_stage_num; ++i)
{
stage_t s = this.stages[i];
if (i > 0 && i < this.level)
{
s.fn = half_sample_25;
s.pre_post = 2 * (half_fir_coefs_25.Length - 1);
s.preload = s.pre = s.pre_post >> 1;
}
s.fifo = new fifo_t(sizeof(double));
s.fifo.reserve(s.preload);
// memset(fifo_reserve(&s->fifo, s->preload), 0, sizeof(double)*s->preload);
// if (i < this.output_stage_num)
// lsx_debug("stage=%-3ipre_post=%-3ipre=%-3ipreload=%i",
// i, s->pre_post, s->pre, s->preload);
}
}
static void half_band_filter_init(rate_shared_t p, int which,
int num_taps, double[] h, double Fp, double att, int multiplier,
double phase, bool allow_aliasing)
{
dft_filter_t f = p.half_band[which];
int dft_length, i;
if (f.num_taps != 0)
return;
if (h != null)
{
dft_length = lsx_set_dft_length(num_taps);
f.coefs = new double[dft_length];
for (i = 0; i < num_taps; ++i)
f.coefs[(i + dft_length - num_taps + 1) & (dft_length - 1)]
= h[Math.Abs(num_taps / 2 - i)] / dft_length * 2 * multiplier;
f.post_peak = num_taps / 2;
}
else
{
h = lsx_design_lpf(Fp, 1.0, 2.0, allow_aliasing, att, ref num_taps, 0);
if (phase != 50)
lsx_fir_to_phase(ref h, ref num_taps, ref f.post_peak, phase, p.info);
else f.post_peak = num_taps / 2;
dft_length = lsx_set_dft_length(num_taps);
f.coefs = new double[dft_length];
for (i = 0; i < num_taps; ++i)
f.coefs[(i + dft_length - num_taps + 1) & (dft_length - 1)]
= h[i] / dft_length * 2 * multiplier;
}
//assert(num_taps & 1);
f.num_taps = num_taps;
f.dft_length = dft_length;
//lsx_debug("fir_len=%i dft_length=%i Fp=%g att=%g mult=%i",
//num_taps, dft_length, Fp, att, multiplier);
SOXFft.safe_rdft(dft_length, 1, f.coefs, p.info);
}