[FFmpeg-cvslog] avfilter: avoid testing float == 0

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Thu May  9 16:41:56 2013 +0200| [3dfc5f551f4c5960afda6f8806ac5779eb2a230b] | committer: Michael Niedermayer

avfilter: avoid testing float == 0

This fixes the hypothetical case of rounding errors causing
incorrect values to be used.
We do not use *_EPSILON, because non trivial expressions can contain
errors larger than that making a zero equality test with *_EPSILON
unreliable.

Signed-off-by: Michael Niedermayer <michaelni at gmx.at>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=3dfc5f551f4c5960afda6f8806ac5779eb2a230b
---

 libavfilter/avfilter.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavfilter/avfilter.c b/libavfilter/avfilter.c
index 83d942c..b577c9a 100644
--- a/libavfilter/avfilter.c
+++ b/libavfilter/avfilter.c
@@ -1062,7 +1062,7 @@ static int ff_filter_frame_framed(AVFilterLink *link, AVFrame *frame)
         dstctx->var_values[VAR_T] = pts == AV_NOPTS_VALUE ? NAN : pts * av_q2d(link->time_base);
         dstctx->var_values[VAR_POS] = pos == -1 ? NAN : pos;
 
-        dstctx->is_disabled = !av_expr_eval(dstctx->enable, dstctx->var_values, NULL);
+        dstctx->is_disabled = fabs(av_expr_eval(dstctx->enable, dstctx->var_values, NULL)) < 0.5;
         if (dstctx->is_disabled &&
             (dstctx->filter->flags & AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC))
             filter_frame = default_filter_frame;