diff options
Diffstat (limited to 'src/libffmpeg/libavcodec/mem.c')
| -rw-r--r-- | src/libffmpeg/libavcodec/mem.c | 46 |
1 files changed, 25 insertions, 21 deletions
diff --git a/src/libffmpeg/libavcodec/mem.c b/src/libffmpeg/libavcodec/mem.c index 462d674e4..24d75e948 100644 --- a/src/libffmpeg/libavcodec/mem.c +++ b/src/libffmpeg/libavcodec/mem.c @@ -14,14 +14,14 @@ * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ - + /** * @file mem.c * default memory allocator for libavcodec. */ - + #include "avcodec.h" /* here we can use OS dependant allocation functions */ @@ -37,7 +37,7 @@ memory allocator. You do not need to suppress this file because the linker will do it automatically */ -/** +/** * Memory allocation of size byte with alignment suitable for all * memory accesses (including vectors if available on the * CPU). av_malloc(0) must return a non NULL pointer. @@ -46,26 +46,26 @@ void *av_malloc(unsigned int size) { void *ptr; #ifdef MEMALIGN_HACK - int diff; + long diff; #endif /* lets disallow possible ambiguous cases */ if(size > INT_MAX) return NULL; - + #ifdef MEMALIGN_HACK ptr = malloc(size+16+1); - diff= ((-(int)ptr - 1)&15) + 1; + diff= ((-(long)ptr - 1)&15) + 1; ptr += diff; ((char*)ptr)[-1]= diff; -#elif defined (HAVE_MEMALIGN) +#elif defined (HAVE_MEMALIGN) ptr = memalign(16,size); - /* Why 64? + /* Why 64? Indeed, we should align it: on 4 for 386 on 16 for 486 - on 32 for 586, PPro - k6-III - on 64 for K7 (maybe for P3 too). + on 32 for 586, PPro - k6-III + on 64 for K7 (maybe for P3 too). Because L1 and L2 caches are aligned on those values. But I don't want to code such logic here! */ @@ -76,14 +76,14 @@ void *av_malloc(unsigned int size) Why not larger? because i didnt see a difference in benchmarks ... */ /* benchmarks with p3 - memalign(64)+1 3071,3051,3032 - memalign(64)+2 3051,3032,3041 - memalign(64)+4 2911,2896,2915 - memalign(64)+8 2545,2554,2550 - memalign(64)+16 2543,2572,2563 - memalign(64)+32 2546,2545,2571 - memalign(64)+64 2570,2533,2558 - + memalign(64)+1 3071,3051,3032 + memalign(64)+2 3051,3032,3041 + memalign(64)+4 2911,2896,2915 + memalign(64)+8 2545,2554,2550 + memalign(64)+16 2543,2572,2563 + memalign(64)+32 2546,2545,2571 + memalign(64)+64 2570,2533,2558 + btw, malloc seems to do 8 byte alignment by default here */ #else @@ -95,7 +95,7 @@ void *av_malloc(unsigned int size) /** * av_realloc semantics (same as glibc): if ptr is NULL and size > 0, * identical to malloc(size). If size is zero, it is identical to - * free(ptr) and NULL is returned. + * free(ptr) and NULL is returned. */ void *av_realloc(void *ptr, unsigned int size) { @@ -117,7 +117,11 @@ void *av_realloc(void *ptr, unsigned int size) #endif } -/* NOTE: ptr = NULL is explicetly allowed */ +/** + * Free memory which has been allocated with av_malloc(z)() or av_realloc(). + * NOTE: ptr = NULL is explicetly allowed + * Note2: it is recommanded that you use av_freep() instead + */ void av_free(void *ptr) { /* XXX: this test should not be needed on most libcs */ |