Some code in alimiter assumes that there are 2 channels, resulting in
clipping if the loudest channel is 3 or above and an out-of-bounds read if
the input is monophonic. Fix that in 2 places.
Signed-off-by: David Flater <d...@flaterco.com>
---
libavfilter/af_alimiter.c | 23 +++++++++++++----------
1 file changed, 13 insertions(+), 10 deletions(-)
diff --git a/libavfilter/af_alimiter.c b/libavfilter/af_alimiter.c
index 622dc66324..c683c4bcf4 100644
--- a/libavfilter/af_alimiter.c
+++ b/libavfilter/af_alimiter.c
@@ -194,10 +194,11 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
} else {
for (i = s->nextiter; i < s->nextiter + s->nextlen; i++) {
int j = i % buffer_size;
- double ppeak, pdelta;
+ double ppeak = 0, pdelta;
- ppeak = fabs(buffer[nextpos[j]]) > fabs(buffer[nextpos[j]
+ 1]) ?
- fabs(buffer[nextpos[j]]) : fabs(buffer[nextpos[j]
+ 1]);
+ for (c = 0; c < channels; c++) {
+ ppeak = FFMAX(ppeak, fabs(buffer[nextpos[j] + c]));
+ }
pdelta = (limit / peak - limit / ppeak) / (((buffer_size -
nextpos[j] + s->pos) % buffer_size) / channels);
if (pdelta < nextdelta[j]) {
nextdelta[j] = pdelta;
@@ -241,14 +242,16 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *in)
s->delta = get_rdelta(s, release, inlink->sample_rate,
peak, limit, s->att, 1);
if (s->nextlen > 1) {
+ double ppeak = 0, pdelta;
int pnextpos = nextpos[(s->nextiter + 1) % buffer_size];
- double ppeak = fabs(buffer[pnextpos]) >
fabs(buffer[pnextpos + 1]) ?
-
fabs(buffer[pnextpos]) :
-
fabs(buffer[pnextpos + 1]);
- double pdelta = (limit / ppeak - s->att) /
- (((buffer_size + pnextpos -
- ((s->pos + channels) % buffer_size)) %
- buffer_size) / channels);
+
+ for (c = 0; c < channels; c++) {
+ ppeak = FFMAX(ppeak, fabs(buffer[pnextpos + c]));
+ }
+ pdelta = (limit / ppeak - s->att) /
+ (((buffer_size + pnextpos -
+ ((s->pos + channels) % buffer_size)) %
+ buffer_size) / channels);
if (pdelta < s->delta)
s->delta = pdelta;
}
--
2.35.3
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