mpd/src/pcm/Interleave.cxx
2023-03-06 18:22:10 +01:00

96 lines
2.0 KiB
C++

// SPDX-License-Identifier: GPL-2.0-or-later
// Copyright The Music Player Daemon Project
#include "Interleave.hxx"
#include <string.h>
static void
GenericPcmInterleave(std::byte *gcc_restrict dest,
std::span<const std::byte *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((std::byte *)dest,
{(const std::byte *const*)src.data(), src.size()},
n_frames, sample_size);
}
}