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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 "Pack.hxx"
#include "util/ByteOrder.hxx"
static void
pack_sample(uint8_t *dest, const int32_t *src0) noexcept
{
const auto *src = (const uint8_t *)src0;
if (IsBigEndian())
++src;
*dest++ = *src++;
*dest++ = *src++;
*dest++ = *src++;
}
void
pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end) noexcept
{
/* duplicate loop to help the compiler's optimizer (constant
parameter to the pack_sample() inline function) */
while (src < src_end) {
pack_sample(dest, src++);
dest += 3;
}
}
/**
* Construct a signed 24 bit integer from three bytes into a int32_t.
*/
static constexpr int32_t
ConstructS24(uint8_t low, uint8_t mid, uint8_t high) noexcept
{
return int32_t(low) | (int32_t(mid) << 8) | (int32_t(high) << 16) |
/* extend the sign bit */
(high & 0x80 ? ~int32_t(0xffffff) : 0);
}
/**
* Read a packed signed little-endian 24 bit integer.
*/
gcc_pure
static int32_t
ReadS24LE(const uint8_t *src) noexcept
{
return ConstructS24(src[0], src[1], src[2]);
}
/**
* Read a packed signed big-endian 24 bit integer.
*/
gcc_pure
static int32_t
ReadS24BE(const uint8_t *src) noexcept
{
return ConstructS24(src[2], src[1], src[0]);
}
/**
* Read a packed signed native-endian 24 bit integer.
*/
gcc_pure
static int32_t
ReadS24(const uint8_t *src) noexcept
{
return IsBigEndian() ? ReadS24BE(src) : ReadS24LE(src);
}
void
pcm_unpack_24(int32_t *dest,
const uint8_t *src, const uint8_t *src_end) noexcept
{
while (src < src_end) {
*dest++ = ReadS24(src);
src += 3;
}
}
void
pcm_unpack_24be(int32_t *dest,
const uint8_t *src, const uint8_t *src_end) noexcept
{
while (src < src_end) {
*dest++ = ReadS24BE(src);
src += 3;
}
}
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