[FFmpeg-user] missing a selected frame

[Ulf Zibis]

Am 19.07.19 um 09:18 schrieb Moritz Barsnick:
> On Fri, Jul 19, 2019 at 00:21:53 +0200, Ulf Zibis wrote:
>> ./ffmpeg -y -v warning -i debug/CYD_1.5m_x264.mp4 -vf
>> select='eq(t\,10.16)+eq(t\,10.2)+eq(t\,10.24)+eq(t\,10.28)+eq(t\,10.32)+eq(t\,10.36)+eq(t\,10.4)+eq(t\,10.44)+eq(t\,17.52)+eq(t\,47.96)+eq(t\,49.08)+eq(t\,49.2)+eq(t\,55.72)+eq(t\,83.0)'
>> -q 5 -c:a copy -vsync vfr debug/outsides/CYD_1.5m_x264_%02d.png
> [...]
>> [Parsed_lineshiftrecover_0 @ 0x55798cbf8f80] frame:    255, pts: 
>> 130560, time:   0:10.2   - optimal shift in line 570 against 569 seems
>> outside of span (-60 - 60), was:   60
>> [Parsed_lineshiftrecover_0 @ 0x55798cbf8f80] frame:    255, pts: 
>> 130560, time:   0:10.2   - optimal shift in line 572 against 571 seems
>> outside of span (-60 - 60), was:   60
> I'm not sure how ffmpeg's expression evaluation calculates 't' (means I
> couldn't find it in the source), but seeing that your av_ts2minutestr()
> certainly does it differently, I may point out: floating point equality
> is a bitch. ;-) I'm saying: 10.2 may not be equal to 10.2,
> computer-mathematically speaking.
Yes, this may be the source of the problem I am facing.

My av_ts2minutestr() does pure integer calculation, so the values I get
from time_base 1/12800 should be exact. See my patch from 03.07.2019,
19:09 CEST in the ffmpeg-devel list.

-Ulf