mpd/src/pcm/Interleave.cxx
2022-07-14 17:59:35 +02:00

112 lines
2.7 KiB
C++

/*
* Copyright 2003-2022 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "Interleave.hxx"
#include <string.h>
static void
GenericPcmInterleave(uint8_t *gcc_restrict dest,
std::span<const uint8_t *const> src,
size_t n_frames, size_t sample_size) noexcept
{
for (size_t frame = 0; frame < n_frames; ++frame) {
for (size_t channel = 0; channel < src.size(); ++channel) {
memcpy(dest, src[channel] + frame * sample_size,
sample_size);
dest += sample_size;
}
}
}
template<typename T>
static void
PcmInterleaveStereo(T *gcc_restrict dest,
const T *gcc_restrict src1,
const T *gcc_restrict src2,
size_t n_frames) noexcept
{
for (size_t i = 0; i != n_frames; ++i) {
*dest++ = *src1++;
*dest++ = *src2++;
}
}
template<typename T>
static void
PcmInterleaveT(T *gcc_restrict dest,
const std::span<const T *const> src,
size_t n_frames) noexcept
{
switch (src.size()) {
case 2:
PcmInterleaveStereo(dest, src[0], src[1], n_frames);
return;
}
for (const auto *s : src) {
auto *d = dest++;
for (const auto *const s_end = s + n_frames;
s != s_end; ++s, d += src.size())
*d = *s;
}
}
static void
PcmInterleave16(int16_t *gcc_restrict dest,
const std::span<const int16_t *const> src,
size_t n_frames) noexcept
{
PcmInterleaveT(dest, src, n_frames);
}
void
PcmInterleave32(int32_t *gcc_restrict dest,
const std::span<const int32_t *const> src,
size_t n_frames) noexcept
{
PcmInterleaveT(dest, src, n_frames);
}
void
PcmInterleave(void *gcc_restrict dest,
std::span<const void *const> src,
size_t n_frames, size_t sample_size) noexcept
{
switch (sample_size) {
case 2:
PcmInterleave16((int16_t *)dest,
{(const int16_t *const*)src.data(), src.size()},
n_frames);
break;
case 4:
PcmInterleave32((int32_t *)dest,
{(const int32_t *const*)src.data(), src.size()},
n_frames);
break;
default:
GenericPcmInterleave((uint8_t *)dest,
{(const uint8_t *const*)src.data(), src.size()},
n_frames, sample_size);
}
}