libswresample: move condition to start of loop.

This avoids several issue like calculating sum/maxcoef
incorrectly due to adding up matrix entries that will
be overwritten, as well as out-of-range writes to
s->matrix if the maximum allowed number of channels is used.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger@gmx.de>
This commit is contained in:
Reimar Döffinger 2014-09-06 21:22:36 +02:00
parent 284123d7fd
commit 2c5c37ade1
1 changed files with 6 additions and 4 deletions

View File

@ -299,18 +299,20 @@ av_cold static int auto_matrix(SwrContext *s)
for(out_i=i=0; i<64; i++){
double sum=0;
int in_i=0;
if((out_ch_layout & (1ULL<<i)) == 0)
continue;
for(j=0; j<64; j++){
if((in_ch_layout & (1ULL<<j)) == 0)
continue;
if (i < FF_ARRAY_ELEMS(matrix) && j < FF_ARRAY_ELEMS(matrix[0]))
s->matrix[out_i][in_i]= matrix[i][j];
else
s->matrix[out_i][in_i]= i == j && (in_ch_layout & out_ch_layout & (1ULL<<i));
sum += fabs(s->matrix[out_i][in_i]);
if(in_ch_layout & (1ULL<<j))
in_i++;
in_i++;
}
maxcoef= FFMAX(maxcoef, sum);
if(out_ch_layout & (1ULL<<i))
out_i++;
out_i++;
}
if(s->rematrix_volume < 0)
maxcoef = -s->rematrix_volume;