32a595222d
Made the OpenMPT / legacy OpenMPT and mpg123 libraries pre-built. Changed the OpenMPT and vgmstream plugins to import the libraries as they are now. Made mpg123 embedded and imported by the main binary, since it's now shared by two plugins. Signed-off-by: Christopher Snowhill <kode54@gmail.com>
103 lines
2.1 KiB
C
103 lines
2.1 KiB
C
/*
|
|
swap_bytes: Swap byte order of samples in a buffer.
|
|
|
|
copyright 2018 by the mpg123 project
|
|
licensed under the terms of the LGPL 2.1
|
|
see COPYING and AUTHORS files in distribution or http://mpg123.org
|
|
|
|
initially written by Thomas Orgis
|
|
|
|
This is C source to include in your code to get the function named
|
|
swap_bytes. It is serves intentional duplication in libmpg123 and
|
|
libsyn123 to avoid introducing a dependency between them. This function
|
|
is too small for that.
|
|
*/
|
|
|
|
/* Other headers are already included! */
|
|
|
|
/* Optionally use platform-specific byteswap macros. */
|
|
#ifdef HAVE_BYTESWAP_H
|
|
#include <byteswap.h>
|
|
#endif
|
|
|
|
/* Plain stupid swapping of elements in a byte array. */
|
|
/* This is the fallback when there is no native bswap macro. */
|
|
#define SWAP(a,b) tmp = p[a]; p[a] = p[b]; p[b] = tmp;
|
|
|
|
/* Convert samplecount elements of samplesize bytes each in buffer buf. */
|
|
static void swap_bytes(void *buf, size_t samplesize, size_t samplecount)
|
|
{
|
|
unsigned char *p = buf;
|
|
unsigned char *pend = (unsigned char*)buf+samplesize*samplecount;
|
|
unsigned char tmp;
|
|
|
|
if(samplesize < 2)
|
|
return;
|
|
switch(samplesize)
|
|
{
|
|
case 2: /* AB -> BA */
|
|
#ifdef HAVE_BYTESWAP_H
|
|
{
|
|
uint16_t* pp = (uint16_t*)p;
|
|
for(; pp<(uint16_t*)pend; ++pp)
|
|
*pp = bswap_16(*pp);
|
|
}
|
|
#else
|
|
for(; p<pend; p+=2)
|
|
{
|
|
SWAP(0,1)
|
|
}
|
|
#endif
|
|
break;
|
|
case 3: /* ABC -> CBA */
|
|
for(; p<pend; p+=3)
|
|
{
|
|
SWAP(0,2)
|
|
}
|
|
break;
|
|
case 4: /* ABCD -> DCBA */
|
|
#ifdef HAVE_BYTESWAP_H
|
|
{
|
|
uint32_t* pp = (uint32_t*)p;
|
|
for(; pp<(uint32_t*)pend; ++pp)
|
|
*pp = bswap_32(*pp);
|
|
}
|
|
#else
|
|
for(; p<pend; p+=4)
|
|
{
|
|
SWAP(0,3)
|
|
SWAP(1,2)
|
|
}
|
|
#endif
|
|
break;
|
|
case 8: /* ABCDEFGH -> HGFEDCBA */
|
|
#ifdef HAVE_BYTESWAP_H
|
|
{
|
|
uint64_t* pp = (uint64_t*)p;
|
|
for(; pp<(uint64_t*)pend; ++pp)
|
|
*pp = bswap_64(*pp);
|
|
}
|
|
#else
|
|
for(; p<pend; p+=8)
|
|
{
|
|
SWAP(0,7)
|
|
SWAP(1,6)
|
|
SWAP(2,5)
|
|
SWAP(3,4)
|
|
}
|
|
#endif
|
|
break;
|
|
/* All the weird choices with the full nested loop. */
|
|
default:
|
|
for(; p<pend; p+=samplesize)
|
|
{
|
|
size_t j;
|
|
for(j=0; j<samplesize/2; ++j)
|
|
{
|
|
SWAP(j, samplesize-j-1)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
#undef SWAP
|