108 lines
2.5 KiB
C++
108 lines
2.5 KiB
C++
/*
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* Copyright 2003-2019 The Music Player Daemon Project
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* http://www.musicpd.org
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "Pack.hxx"
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#include "util/ByteOrder.hxx"
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static void
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pack_sample(uint8_t *dest, const int32_t *src0) noexcept
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{
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const uint8_t *src = (const uint8_t *)src0;
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if (IsBigEndian())
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++src;
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*dest++ = *src++;
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*dest++ = *src++;
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*dest++ = *src++;
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}
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void
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pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end) noexcept
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{
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/* duplicate loop to help the compiler's optimizer (constant
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parameter to the pack_sample() inline function) */
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while (src < src_end) {
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pack_sample(dest, src++);
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dest += 3;
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}
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}
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/**
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* Construct a signed 24 bit integer from three bytes into a int32_t.
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*/
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static constexpr int32_t
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ConstructS24(uint8_t low, uint8_t mid, uint8_t high) noexcept
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{
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return int32_t(low) | (int32_t(mid) << 8) | (int32_t(high) << 16) |
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/* extend the sign bit */
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(high & 0x80 ? ~int32_t(0xffffff) : 0);
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}
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/**
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* Read a packed signed little-endian 24 bit integer.
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*/
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gcc_pure
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static int32_t
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ReadS24LE(const uint8_t *src) noexcept
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{
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return ConstructS24(src[0], src[1], src[2]);
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}
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/**
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* Read a packed signed big-endian 24 bit integer.
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*/
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gcc_pure
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static int32_t
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ReadS24BE(const uint8_t *src) noexcept
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{
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return ConstructS24(src[2], src[1], src[0]);
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}
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/**
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* Read a packed signed native-endian 24 bit integer.
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*/
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gcc_pure
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static int32_t
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ReadS24(const uint8_t *src) noexcept
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{
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return IsBigEndian() ? ReadS24BE(src) : ReadS24LE(src);
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}
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void
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pcm_unpack_24(int32_t *dest,
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const uint8_t *src, const uint8_t *src_end) noexcept
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{
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while (src < src_end) {
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*dest++ = ReadS24(src);
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src += 3;
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}
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}
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void
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pcm_unpack_24be(int32_t *dest,
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const uint8_t *src, const uint8_t *src_end) noexcept
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{
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while (src < src_end) {
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*dest++ = ReadS24BE(src);
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src += 3;
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}
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}
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