avutil/integer: Fix av_mod_i() with negative dividend

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
This commit is contained in:
Michael Niedermayer 2015-12-01 12:41:43 +01:00
parent 8e7f452022
commit 3a9cb18855
1 changed files with 8 additions and 0 deletions

View File

@ -29,6 +29,8 @@
#include "integer.h"
#include "avassert.h"
static const AVInteger zero_i;
AVInteger av_add_i(AVInteger a, AVInteger b){
int i, carry=0;
@ -111,6 +113,12 @@ AVInteger av_mod_i(AVInteger *quot, AVInteger a, AVInteger b){
AVInteger quot_temp;
if(!quot) quot = &quot_temp;
if ((int16_t)a.v[AV_INTEGER_SIZE-1] < 0) {
a = av_mod_i(quot, av_sub_i(zero_i, a), b);
*quot = av_sub_i(zero_i, *quot);
return av_sub_i(zero_i, a);
}
av_assert2((int16_t)a.v[AV_INTEGER_SIZE-1] >= 0 && (int16_t)b.v[AV_INTEGER_SIZE-1] >= 0);
av_assert2(av_log2_i(b)>=0);