/* * 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; } } }