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/*
* Copyright 2003-2021 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 "Dop.hxx"
#include "ChannelDefs.hxx"
#include "util/ConstBuffer.hxx"
#include <cassert>
#include <functional>
static constexpr uint32_t
pcm_two_dsd_to_dop_marker1(uint8_t a, uint8_t b) noexcept
{
return 0xff050000 | (a << 8) | b;
}
static constexpr uint32_t
pcm_two_dsd_to_dop_marker2(uint8_t a, uint8_t b) noexcept
{
return 0xfffa0000 | (a << 8) | b;
}
/**
* @param num_dop_quads the number of "quad" bytes per channel in the
* source buffer; each "quad" will be converted to two 24 bit samples
* in the destination buffer, one for each marker
*/
static void
DsdToDop(uint32_t *dest, const uint8_t *src,
size_t num_dop_quads, unsigned channels) noexcept
{
for (size_t i = num_dop_quads; i > 0; --i) {
for (unsigned c = channels; c > 0; --c) {
/* each 24 bit sample has 16 DSD sample bits
plus the magic 0x05 marker */
*dest++ = pcm_two_dsd_to_dop_marker1(src[0], src[channels]);
/* seek the source pointer to the next
channel */
++src;
}
/* skip the second byte of each channel, because we
have already copied it */
src += channels;
for (unsigned c = channels; c > 0; --c) {
/* each 24 bit sample has 16 DSD sample bits
plus the magic 0xfa marker */
*dest++ = pcm_two_dsd_to_dop_marker2(src[0], src[channels]);
/* seek the source pointer to the next
channel */
++src;
}
/* skip the second byte of each channel, because we
have already copied it */
src += channels;
}
}
void
DsdToDopConverter::Open(unsigned _channels) noexcept
{
assert(audio_valid_channel_count(_channels));
channels = _channels;
rest_buffer.Open(channels);
}
ConstBuffer<uint32_t>
DsdToDopConverter::Convert(ConstBuffer<uint8_t> src) noexcept
{
return rest_buffer.Process<uint32_t>(buffer, src, 2 * channels,
[=](auto && arg1, auto && arg2, auto && arg3) { return DsdToDop(arg1, arg2, arg3, channels); });
}
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