mpd/src/pcm/Dsd32.cxx
2019-06-18 11:19:27 +02:00

72 lines
2.0 KiB
C++

/*
* Copyright 2003-2019 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 "Dsd32.hxx"
#include "util/ConstBuffer.hxx"
#include <functional>
/**
* Construct a 32 bit integer from four bytes.
*/
static constexpr uint32_t
Construct32(uint8_t a, uint8_t b, uint8_t c, uint8_t d) noexcept
{
/* "a" is the oldest byte, which must be in the most
significant byte */
return uint32_t(d) | (uint32_t(c) << 8) |
(uint32_t(b) << 16) | (uint32_t(a) << 24);
}
static constexpr uint32_t
Dsd8To32Sample(const uint8_t *src, unsigned channels) noexcept
{
return Construct32(src[0], src[channels],
src[2 * channels], src[3 * channels]);
}
static void
Dsd8To32(uint32_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++ = Dsd8To32Sample(src++, channels);
src += 3 * channels;
}
}
void
Dsd32Converter::Open(unsigned _channels) noexcept
{
channels = _channels;
rest_buffer.Open(channels);
}
ConstBuffer<uint32_t>
Dsd32Converter::Convert(ConstBuffer<uint8_t> src) noexcept
{
using namespace std::placeholders;
return rest_buffer.Process<uint32_t>(buffer, src, channels,
std::bind(Dsd8To32, _1, _2, _3, channels));
}