diff options
Diffstat (limited to 'src/util')
| -rw-r--r-- | src/util/byte_reverse.c | 123 | ||||
| -rw-r--r-- | src/util/byte_reverse.h | 55 |
2 files changed, 178 insertions, 0 deletions
diff --git a/src/util/byte_reverse.c b/src/util/byte_reverse.c new file mode 100644 index 000000000..e96af14b9 --- /dev/null +++ b/src/util/byte_reverse.c @@ -0,0 +1,123 @@ +/* + * Copyright (C) 2003-2012 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 "byte_reverse.h" + +#include <glib.h> +#include <assert.h> + +void +reverse_bytes_16(uint16_t *dest, const uint16_t *src, const uint16_t *src_end) +{ + assert(dest != NULL); + assert(src != NULL); + assert(src_end >= src); + + while (src < src_end) { + const uint16_t x = *src++; + *dest++ = GUINT16_SWAP_LE_BE(x); + } +} + +void +reverse_bytes_32(uint32_t *dest, const uint32_t *src, const uint32_t *src_end) +{ + assert(dest != NULL); + assert(src != NULL); + assert(src_end >= src); + + while (src < src_end) { + const uint32_t x = *src++; + *dest++ = GUINT32_SWAP_LE_BE(x); + } +} + +void +reverse_bytes_64(uint64_t *dest, const uint64_t *src, const uint64_t *src_end) +{ + assert(dest != NULL); + assert(src != NULL); + assert(src_end >= src); + + while (src < src_end) { + const uint64_t x = *src++; + *dest++ = GUINT64_SWAP_LE_BE(x); + } +} + +static void +reverse_bytes_linear(uint8_t *dest, const uint8_t *src, size_t n) +{ + src += n; + + while (n-- > 0) + *dest++ = *--src; +} + +static void +reverse_bytes_generic(uint8_t *dest, + const uint8_t *src, const uint8_t *src_end, + size_t frame_size) +{ + assert(dest != NULL); + assert(src != NULL); + assert(src_end >= src); + assert(frame_size > 0); + assert((src_end - src) % frame_size == 0); + + while (src < src_end) { + reverse_bytes_linear(dest, src, frame_size); + dest += frame_size; + src += frame_size; + } +} + +void +reverse_bytes(uint8_t *dest, const uint8_t *src, const uint8_t *src_end, + size_t frame_size) +{ + assert(dest != NULL); + assert(src != NULL); + assert(src_end >= src); + assert(frame_size > 0); + assert((src_end - src) % frame_size == 0); + + switch (frame_size) { + case 2: + reverse_bytes_16((uint16_t *)dest, + (const uint16_t *)src, + (const uint16_t *)src_end); + break; + + case 4: + reverse_bytes_32((uint32_t *)dest, + (const uint32_t *)src, + (const uint32_t *)src_end); + break; + + case 8: + reverse_bytes_64((uint64_t *)dest, + (const uint64_t *)src, + (const uint64_t *)src_end); + break; + + default: + reverse_bytes_generic(dest, src, src_end, frame_size); + } +} diff --git a/src/util/byte_reverse.h b/src/util/byte_reverse.h new file mode 100644 index 000000000..63213d6c2 --- /dev/null +++ b/src/util/byte_reverse.h @@ -0,0 +1,55 @@ +/* + * Copyright (C) 2003-2012 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. + */ + +#ifndef MPD_BYTE_REVERSE_H +#define MPD_BYTE_REVERSE_H + +#include <stdint.h> +#include <stddef.h> + +/** + * Reverse the bytes in each 16 bit "frame". This function can be + * used for in-place operation. + */ +void +reverse_bytes_16(uint16_t *dest, const uint16_t *src, const uint16_t *src_end); + +/** + * Reverse the bytes in each 32 bit "frame". This function can be + * used for in-place operation. + */ +void +reverse_bytes_32(uint32_t *dest, const uint32_t *src, const uint32_t *src_end); + +/** + * Reverse the bytes in each 64 bit "frame". This function can be + * used for in-place operation. + */ +void +reverse_bytes_64(uint64_t *dest, const uint64_t *src, const uint64_t *src_end); + +/** + * Reverse the bytes in each "frame". This function cannot be used + * for in-place operation. + */ +void +reverse_bytes(uint8_t *dest, const uint8_t *src, const uint8_t *src_end, + size_t frame_size); + +#endif |