swresample: Skip over dither steps if dithering scale is 0

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

1 files changed, 5 insertions, 0 deletions

diff --git a/libswresample/dither.c b/libswresample/dither.c
index 76f8ccf2c6..64068d35b6 100644
--- a/libswresample/dither.c
+++ b/libswresample/dither.c
@@ -102,6 +102,11 @@ av_cold int swri_dither_init(SwrContext *s, enum AVSampleFormat out_fmt, enum AV
     if (out_fmt == AV_SAMPLE_FMT_S32 && s->dither.output_sample_bits)
         scale *= 1<<(32-s->dither.output_sample_bits);
 
+    if (scale == 0) {
+        s->dither.method = 0;
+        return 0;
+    }
+
     s->dither.ns_pos = 0;
     s->dither.noise_scale=   scale;
     s->dither.ns_scale   =   scale;