mpd/src/pcm/Dsd16.cxx
2022-07-14 17:59:35 +02:00

66 lines
1.8 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 "Dsd16.hxx"
/**
* Construct a 16 bit integer from two bytes.
*/
static constexpr uint16_t
Construct16(uint8_t a, uint8_t b) noexcept
{
/* "a" is the oldest byte, which must be in the most
significant byte */
return uint16_t(b) | (uint16_t(a) << 8);
}
static constexpr uint16_t
Dsd8To16Sample(const uint8_t *src, unsigned channels) noexcept
{
return Construct16(src[0], src[channels]);
}
static void
Dsd8To16(uint16_t *dest, const uint8_t *src,
size_t out_frames, unsigned channels) noexcept
{
for (size_t i = 0; i < out_frames; ++i) {
for (size_t c = 0; c < channels; ++c)
*dest++ = Dsd8To16Sample(src++, channels);
src += channels;
}
}
void
Dsd16Converter::Open(unsigned _channels) noexcept
{
channels = _channels;
rest_buffer.Open(channels);
}
std::span<const uint16_t>
Dsd16Converter::Convert(std::span<const uint8_t> src) noexcept
{
return rest_buffer.Process<uint16_t>(buffer, src, channels,
[this](auto && arg1, auto && arg2, auto && arg3) { return Dsd8To16(arg1, arg2, arg3, channels); });
}