[FFmpeg-devel] [PATCH] avfilter/vf_psnr: Fix rounding error in average_max

Michael Niedermayer michael at niedermayer.cc
Thu Jul 21 03:04:03 EEST 2016


The intermediate was rounded to an integer

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavfilter/vf_psnr.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libavfilter/vf_psnr.c b/libavfilter/vf_psnr.c
index f3dff62..54d4ff0 100644
--- a/libavfilter/vf_psnr.c
+++ b/libavfilter/vf_psnr.c
@@ -246,6 +246,7 @@ static int config_input_ref(AVFilterLink *inlink)
     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
     AVFilterContext *ctx  = inlink->dst;
     PSNRContext *s = ctx->priv;
+    double average_max;
     unsigned sum;
     int j;
 
@@ -278,10 +279,12 @@ static int config_input_ref(AVFilterLink *inlink)
     sum = 0;
     for (j = 0; j < s->nb_components; j++)
         sum += s->planeheight[j] * s->planewidth[j];
+    average_max = 0;
     for (j = 0; j < s->nb_components; j++) {
         s->planeweight[j] = (double) s->planeheight[j] * s->planewidth[j] / sum;
-        s->average_max += s->max[j] * s->planeweight[j];
+        average_max += s->max[j] * s->planeweight[j];
     }
+    s->average_max = lrint(average_max);
 
     s->dsp.sse_line = desc->comp[0].depth > 8 ? sse_line_16bit : sse_line_8bit;
     if (ARCH_X86)
-- 
1.7.9.5



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