diff options
Diffstat (limited to 'src/pcm/PcmPack.cxx')
-rw-r--r-- | src/pcm/PcmPack.cxx | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/pcm/PcmPack.cxx b/src/pcm/PcmPack.cxx new file mode 100644 index 000000000..fa020bf63 --- /dev/null +++ b/src/pcm/PcmPack.cxx @@ -0,0 +1,77 @@ +/* + * Copyright (C) 2003-2013 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 "PcmPack.hxx" + +#include <glib.h> + +static void +pack_sample(uint8_t *dest, const int32_t *src0) +{ + const uint8_t *src = (const uint8_t *)src0; + + if (G_BYTE_ORDER == G_BIG_ENDIAN) + ++src; + + *dest++ = *src++; + *dest++ = *src++; + *dest++ = *src++; +} + +void +pcm_pack_24(uint8_t *dest, const int32_t *src, const int32_t *src_end) +{ + /* 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; + } +} + +static void +unpack_sample(int32_t *dest0, const uint8_t *src) +{ + uint8_t *dest = (uint8_t *)dest0; + + if (G_BYTE_ORDER == G_BIG_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) + /* 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, const uint8_t *src_end) +{ + /* duplicate loop to help the compiler's optimizer (constant + parameter to the unpack_sample() inline function) */ + + while (src < src_end) { + unpack_sample(dest++, src); + src += 3; + } +} |