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/*
* Copyright (C) 2003-2010 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 "pcm_pack.h"
#include <glib.h>
static void
pack_sample(uint8_t *dest, const int32_t *src0, bool reverse_endian)
{
const uint8_t *src = (const uint8_t *)src0;
if ((G_BYTE_ORDER == G_BIG_ENDIAN) != reverse_endian)
++src;
*dest++ = *src++;
*dest++ = *src++;
*dest++ = *src++;
}
void
pcm_pack_24(uint8_t *dest, const int32_t *src, unsigned num_samples,
bool reverse_endian)
{
/* duplicate loop to help the compiler's optimizer (constant
parameter to the pack_sample() inline function) */
if (G_LIKELY(!reverse_endian)) {
while (num_samples-- > 0) {
pack_sample(dest, src++, false);
dest += 3;
}
} else {
while (num_samples-- > 0) {
pack_sample(dest, src++, true);
dest += 3;
}
}
}
static void
unpack_sample(int32_t *dest0, const uint8_t *src, bool reverse_endian)
{
uint8_t *dest = (uint8_t *)dest0;
if ((G_BYTE_ORDER == G_BIG_ENDIAN) != reverse_endian)
/* extend the sign bit to the most fourth byte */
*dest++ = *src & 0x80 ? 0xff : 0x00;
*dest++ = *src++;
*dest++ = *src++;
*dest++ = *src;
if ((G_BYTE_ORDER == G_LITTLE_ENDIAN) != reverse_endian)
/* extend the sign bit to the most fourth byte */
*dest++ = *src & 0x80 ? 0xff : 0x00;
}
void
pcm_unpack_24(int32_t *dest, const uint8_t *src, unsigned num_samples,
bool reverse_endian)
{
/* duplicate loop to help the compiler's optimizer (constant
parameter to the unpack_sample() inline function) */
if (G_LIKELY(!reverse_endian)) {
while (num_samples-- > 0) {
unpack_sample(dest++, src, false);
src += 3;
}
} else {
while (num_samples-- > 0) {
unpack_sample(dest++, src, true);
src += 3;
}
}
}
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