Commit 275dfb83 authored by Alexander E. Patrakov's avatar Alexander E. Patrakov Committed by Alexandre Julliard

dsound: Added a windowed-sinc resampler.

parent 0789ec11
......@@ -183,7 +183,8 @@ struct IDirectSoundBufferImpl
DSBUFFERDESC dsbd;
/* used for frequency conversion (PerfectPitch) */
ULONG freqneeded;
float freqAcc, freqAdjust;
DWORD firstep;
float freqAcc, freqAdjust, firgain;
/* used for mixing */
DWORD primary_mixpos, sec_mixpos;
......
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......@@ -40,6 +40,7 @@
#include "ks.h"
#include "ksmedia.h"
#include "dsound_private.h"
#include "fir.h"
WINE_DEFAULT_DEBUG_CHANNEL(dsound);
......@@ -129,6 +130,24 @@ void DSOUND_RecalcFormat(IDirectSoundBufferImpl *dsb)
&& (IsEqualGUID(&pwfxe->SubFormat, &KSDATAFORMAT_SUBTYPE_IEEE_FLOAT))))
ieee = TRUE;
/**
* Recalculate FIR step and gain.
*
* firstep says how many points of the FIR exist per one
* sample in the secondary buffer. firgain specifies what
* to multiply the FIR output by in order to attenuate it correctly.
*/
if (dsb->freqAdjust > 1.0f) {
/**
* Yes, round it a bit to make sure that the
* linear interpolation factor never changes.
*/
dsb->firstep = ceil(fir_step / dsb->freqAdjust);
} else {
dsb->firstep = fir_step;
}
dsb->firgain = (float)dsb->firstep / fir_step;
/* calculate the 10ms write lead */
dsb->writelead = (dsb->freq / 100) * dsb->pwfx->nBlockAlign;
......@@ -228,28 +247,97 @@ static inline float get_current_sample(const IDirectSoundBufferImpl *dsb,
return dsb->get(dsb, mixpos % dsb->buflen, channel);
}
/**
* Copy frames from the given input buffer to the given output buffer.
* Translate 8 <-> 16 bits and mono <-> stereo
*/
static inline void cp_fields(IDirectSoundBufferImpl *dsb,
static UINT cp_fields_noresample(IDirectSoundBufferImpl *dsb,
UINT ostride, UINT count)
{
UINT istride = dsb->pwfx->nBlockAlign;
DWORD channel, i;
for (i = 0; i < count; i++)
for (channel = 0; channel < dsb->mix_channels; channel++)
dsb->put(dsb, i * ostride, channel, get_current_sample(dsb,
dsb->sec_mixpos + i * istride, channel));
return count;
}
static UINT cp_fields_resample(IDirectSoundBufferImpl *dsb,
UINT ostride, UINT count, float *freqAcc)
{
DWORD ipos = dsb->sec_mixpos;
UINT istride = dsb->pwfx->nBlockAlign, i;
DWORD opos = 0;
UINT i, channel;
UINT istride = dsb->pwfx->nBlockAlign;
float freqAdjust = dsb->freqAdjust;
float freqAcc_start = *freqAcc;
float freqAcc_end = freqAcc_start + count * freqAdjust;
UINT dsbfirstep = dsb->firstep;
UINT channels = dsb->mix_channels;
UINT max_ipos = freqAcc_start + count * freqAdjust;
UINT fir_cachesize = (fir_len + dsbfirstep - 2) / dsbfirstep;
UINT required_input = max_ipos + fir_cachesize;
float* intermediate = HeapAlloc(GetProcessHeap(), 0,
sizeof(float) * required_input * channels);
float* fir_copy = HeapAlloc(GetProcessHeap(), 0,
sizeof(float) * fir_cachesize);
/* Important: this buffer MUST be non-interleaved
* if you want -msse3 to have any effect.
* This is good for CPU cache effects, too.
*/
float* itmp = intermediate;
for (channel = 0; channel < channels; channel++)
for (i = 0; i < required_input; i++)
*(itmp++) = get_current_sample(dsb,
dsb->sec_mixpos + i * istride, channel);
for(i = 0; i < count; ++i) {
float total_fir_steps = (freqAcc_start + i * freqAdjust) * dsbfirstep;
UINT int_fir_steps = total_fir_steps;
UINT ipos = int_fir_steps / dsbfirstep;
UINT idx = (ipos + 1) * dsbfirstep - int_fir_steps - 1;
float rem = int_fir_steps + 1.0 - total_fir_steps;
int fir_used = 0;
while (idx < fir_len - 1) {
fir_copy[fir_used++] = fir[idx] * (1.0 - rem) + fir[idx + 1] * rem;
idx += dsb->firstep;
}
for (i = 0; i < count; ++i){
DWORD channel;
for (channel = 0; channel < dsb->mix_channels; channel++)
dsb->put(dsb, opos, channel,
get_current_sample(dsb, ipos, channel));
*freqAcc += dsb->freqAdjust;
ipos += ((DWORD)*freqAcc) * istride;
*freqAcc -= truncf(*freqAcc);
opos += ostride;
assert(fir_used <= fir_cachesize);
assert(ipos + fir_used <= required_input);
for (channel = 0; channel < dsb->mix_channels; channel++) {
int j;
float sum = 0.0;
float* cache = &intermediate[channel * required_input + ipos];
for (j = 0; j < fir_used; j++)
sum += fir_copy[j] * cache[j];
dsb->put(dsb, i * ostride, channel, sum * dsb->firgain);
}
}
freqAcc_end -= (int)freqAcc_end;
*freqAcc = freqAcc_end;
HeapFree(GetProcessHeap(), 0, fir_copy);
HeapFree(GetProcessHeap(), 0, intermediate);
return max_ipos;
}
static void cp_fields(IDirectSoundBufferImpl *dsb,
UINT ostride, UINT count, float *freqAcc)
{
DWORD ipos, adv;
if (dsb->freqAdjust == 1.0)
adv = cp_fields_noresample(dsb, ostride, count); /* *freqAcc is unmodified */
else
adv = cp_fields_resample(dsb, ostride, count, freqAcc);
ipos = dsb->sec_mixpos + adv * dsb->pwfx->nBlockAlign;
if (ipos >= dsb->buflen) {
if (dsb->playflags & DSBPLAY_LOOPING)
ipos %= dsb->buflen;
......
#! /usr/bin/perl -w
#
# DirectSound
#
# Copyright 2011-2012 Alexander E. Patrakov
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
use strict;
use Math::Trig;
# This program generates an array of Finite Impulse Response (FIR) filter
# values for use in resampling audio.
#
# Values are based on the resampler from Windows XP at the default (best)
# quality, reverse engineered by saving kvm output to a wav file.
# Controls how sharp the transition between passband and stopband is.
# The transition bandwidth is approximately (1 / exp_width) of the
# Nyquist frequency.
my $exp_width = 41.0;
# Controls the stopband attenuation. It is related but not proportional
# to exp(-(PI * lobes_per_wing / exp_width) ^2) / lobes_per_wing
my $lobes_per_wing = 28;
# Controls the position of the transition band and thus attenuation at the
# Nyquist frequency and above. Amended below so that the length of the FIR is
# an integer. Essentially, this controls the trade-off between good rejection
# of unrepresentable frequencies (those above half of the lower of the sample
# rates) and not rejecting the wanted ones. Windows XP errs on the side of
# letting artifacts through, which somewhat makes sense if they are above
# 20 kHz anyway, or in the case of upsampling, where we can assume that the
# problematic frequencies are not in the input. This, however, doesn't match
# what linux resamplers do - so set this to 0.85 to match them. 0.98 would
# give Windows XP behaviour.
my $approx_bandwidth = 0.85;
# The amended value will be stored here
my $bandwidth;
# The number of points per time unit equal to one period of the original
# Nyquist frequency. The more points, the less interpolation error is.
my $fir_step = 120;
# Here x is measured in half-periods of the lower sample rate
sub fir_val($)
{
my ($x) = @_;
$x *= pi * $bandwidth;
my $s = $x / $exp_width;
my $sinc = $x ? (sin($x) / $x) : 1.0;
my $gauss = exp(-($s * $s));
return $sinc * $gauss;
}
# Linear interpolation
sub mlinear($$$)
{
my ($y1, $y2, $mu) = @_;
return $y1 * (1.0 - $mu) + $y2 * $mu;
}
# to_db, for printing decibel values
sub to_db($) {
my ($x) = @_;
return 20.0 * log(abs($x))/log(10.0);
}
my $wing_len = int($lobes_per_wing / $approx_bandwidth * $fir_step + 1);
$bandwidth = 1.0 * $lobes_per_wing / $wing_len;
my $amended_bandwidth = $bandwidth * $fir_step;
my $fir_len = 2 * $wing_len + 1;
my @fir;
# Constructing the FIR is easy
for (my $i = 0; $i < $fir_len; $i++) {
push @fir, fir_val($i - $wing_len);
}
# Now we have to test it and print some statistics to stderr.
# Test 0: FIR size
print STDERR "size: $fir_len\n";
# Test 1: Interpolation noise. It should be less than -90 dB.
# If you suspect that 0.5 is special due to some symmetry and thus yields
# an abnormally low noise figure, change it. But really, it isn't special.
my $testpoint = 0.5;
my $exact_val = fir_val($testpoint);
my $lin_approx_val = mlinear($fir[$wing_len], $fir[$wing_len + 1],
$testpoint);
my $lin_error_db = to_db($exact_val - $lin_approx_val);
printf STDERR "interpolation noise: %1.2f dB\n", $lin_error_db;
# Test 2: Passband and stopband.
# The filter gain, ideally, should be 0.00 dB below the Nyquist
# frequency and -inf dB above it. But it is impossible. So
# let's settle for -80 dB above 1.08 * f_Nyquist.
my $sum = 0.0;
$sum += $_ for @fir;
# Frequencies in this list are expressed as fractions
# of the Nyquist frequency.
my @testfreqs = (0.5, 0.8, 1.0, 1.08, 1.18, 1.33, 1.38);
foreach my $testfreq(@testfreqs) {
my $dct_coeff = 0.0;
for (my $i = 0; $i < $fir_len; $i++) {
my $x = 1.0 * ($i - $wing_len) / $fir_step;
$dct_coeff += $fir[$i] * cos($x * $testfreq * pi);
}
printf STDERR "DCT: %1.2f -> %1.2f dB\n",
$testfreq, to_db($dct_coeff / $sum);
}
# Now actually print the FIR to a C header file
chdir ".." if -f "./make_fir";
open FILE, ">dlls/dsound/fir.h";
select FILE;
print "/* generated by tools/make_fir; DO NOT EDIT! */\n";
print "static const int fir_len = $fir_len;\n";
print "static const int fir_step = $fir_step;\n";
print "static const float fir[] = {\n";
for (my $i = 0; $i < $fir_len; $i++) {
printf "%10.10f", $amended_bandwidth * $fir[$i];
if ($i == $fir_len - 1) {
print "\n";
} elsif (($i + 1) % 5 == 0) {
print ",\n";
} else {
print ", ";
}
}
print "};\n";
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