[a0a02d]: runtime / resample.cpp  Maximize  Restore  History

Download this file

111 lines (95 with data), 2.8 kB

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
// Copyright (C) 2008-2011 David Sugar, Tycho Softworks.
//
// This file is part of GNU Bayonne.
//
// GNU Bayonne is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
//
// GNU Bayonne 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with GNU Bayonne. If not, see <http://www.gnu.org/licenses/>.
#include <bayonne-config.h>
#include <ucommon/ucommon.h>
#include <ucommon/export.h>
#include <bayonne.h>
using namespace BAYONNE_NAMESPACE;
using namespace UCOMMON_NAMESPACE;
Audio::resample::resample(Audio::rate_t div, Audio::rate_t mul)
{
bool common = true;
while(common) {
common = false;
while(!(mul & 0x01) && !(div & 0x01)) {
mul = (Audio::rate_t)(mul >> 1);
div = (Audio::rate_t)(div >> 1);
common = true;
}
while(!(mul % 3) && !(div % 3)) {
mul = (Audio::rate_t)(mul / 3);
div = (Audio::rate_t)(div / 3);
common = true;
}
while(!(mul % 5) && !(div %5)) {
mul = (rate_t)(mul / 5);
div = (rate_t)(div / 5);
common = true;
}
}
mfact = (unsigned)mul;
dfact = (unsigned)div;
max = mfact;
if(dfact > mfact)
max = dfact;
++max;
buffer = new Audio::sample_t[max];
ppos = gpos = 0;
memset(buffer, 0, max * 2);
last = 0;
}
Audio::resample::~resample()
{
delete[] buffer;
}
size_t Audio::resample::estimate(size_t count)
{
count *= mfact;
count += (mfact - 1);
return (count / dfact) + 1;
}
size_t Audio::resample::process(linear_t from, linear_t dest, size_t count)
{
size_t saved = 0;
sample_t diff, current;
unsigned pos;
unsigned dpos;
while(count--) {
current = *(from++);
diff = (current - last) / mfact;
pos = mfact;
while(pos--) {
last += diff;
buffer[ppos++] = current;
if(ppos >= max)
ppos = 0;
if(gpos < ppos)
dpos = ppos - gpos;
else
dpos = max - (gpos - ppos);
if(dpos >= dfact) {
*(dest++) = buffer[gpos];
++saved;
gpos += dfact;
if(gpos >= max)
gpos = gpos - max;
}
}
last = current;
}
return saved;
}