On 1/4/20, zhilizhao <quinkbl...@foxmail.com> wrote: > > >> On Jan 4, 2020, at 7:04 PM, Paul B Mahol <one...@gmail.com> wrote: >> >> I do not like this “fix" > > What do you suggest? It’s numerical unstable for small sigma.
For small sigma return frames unchanged as it currently does. > >> >> On 1/4/20, quinkbl...@foxmail.com <quinkbl...@foxmail.com> wrote: >>> From: Zhao Zhili <zhiliz...@tencent.com> >>> >>> ./ffmpeg -i ~/Pictures/test.jpg -vf 'gblur=sigma=0' -f null - >>> ... >>> src/libavfilter/vf_gblur.c:260:59: runtime error: division by zero >>> src/libavfilter/vf_gblur.c:261:26: runtime error: division by zero >>> --- >>> libavfilter/vf_gblur.c | 12 +++++++++--- >>> 1 file changed, 9 insertions(+), 3 deletions(-) >>> >>> diff --git a/libavfilter/vf_gblur.c b/libavfilter/vf_gblur.c >>> index 2e587f6a0a..e057937fb7 100644 >>> --- a/libavfilter/vf_gblur.c >>> +++ b/libavfilter/vf_gblur.c >>> @@ -37,11 +37,17 @@ >>> #define OFFSET(x) offsetof(GBlurContext, x) >>> #define FLAGS >>> AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_RUNTIME_PARAM >>> >>> +/* Consider the three-sigma rule, for minimum radius of 1 sigma should >>> not >>> + * be smaller than 1/3. Relax it to 0.25 if the user want to try. >>> + */ >>> +#define SIGMA_MIN 0.25 >>> +#define SIGMA_MAX 1024.0 >>> + >>> static const AVOption gblur_options[] = { >>> - { "sigma", "set sigma", OFFSET(sigma), >>> AV_OPT_TYPE_FLOAT, >>> {.dbl=0.5}, 0.0, 1024, FLAGS }, >>> + { "sigma", "set sigma", OFFSET(sigma), >>> AV_OPT_TYPE_FLOAT, >>> {.dbl=0.5}, SIGMA_MIN, SIGMA_MAX, FLAGS }, >>> { "steps", "set number of steps", OFFSET(steps), AV_OPT_TYPE_INT, >>> {.i64=1}, 1, 6, FLAGS }, >>> { "planes", "set planes to filter", OFFSET(planes), AV_OPT_TYPE_INT, >>> {.i64=0xF}, 0, 0xF, FLAGS }, >>> - { "sigmaV", "set vertical sigma", OFFSET(sigmaV), >>> AV_OPT_TYPE_FLOAT, >>> {.dbl=-1}, -1, 1024, FLAGS }, >>> + { "sigmaV", "set vertical sigma", OFFSET(sigmaV), >>> AV_OPT_TYPE_FLOAT, >>> {.dbl=-1}, -1, SIGMA_MAX, FLAGS }, >>> { NULL } >>> }; >>> >>> @@ -244,7 +250,7 @@ static int config_input(AVFilterLink *inlink) >>> if (!s->buffer) >>> return AVERROR(ENOMEM); >>> >>> - if (s->sigmaV < 0) { >>> + if (s->sigmaV < SIGMA_MIN) { >>> s->sigmaV = s->sigma; >>> } >>> ff_gblur_init(s); >>> -- >>> 2.22.0 >>> >>> _______________________________________________ >>> ffmpeg-devel mailing list >>> ffmpeg-devel@ffmpeg.org >>> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >>> >>> To unsubscribe, visit link above, or email >>> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". >> _______________________________________________ >> ffmpeg-devel mailing list >> ffmpeg-devel@ffmpeg.org >> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel >> >> To unsubscribe, visit link above, or email >> ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". > > > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe". _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".