ffmpeg use drawtext filter, text doesn't appear correctly in given time

[slick zheng]

I have a video which is produced by ffmpeg concat images, like "ffmpeg -f concat -i concat.txt output.mp4"
then I want add some text in the output video, so I use command

ffmpeg -y -i ./tmp/6ir0TW/concat.mp4 -vf "drawtext=text='hello':x=(w-text_w)/2:y=(h-100):fontsize=50:fontcolor=white:enable='between(t,0,1)',drawtext=text='world':x=(w-text_w)/2:y=(h-100):fontsize=50:fontcolor=white:enable='between(t,1,2)',drawtext=text='this is':x=(w-text_w)/2:y=(h-100):fontsize=50:fontcolor=white:enable='between(t,2,3)'" ./tmp/6ir0TW/draw_text.mp4

my expectation is hello appear in the beginning, then hello disappear, world appear...
but in the output I only see hello in the first 5 seconds. Does anyone know how can I fix this?
In attachment is concated video file.

[poisondeathray]

The timestamps in your input video do not have enough "granularity" to specify between seconds. Individual frames displayed for a long time (ie. it's effectively a very low fps video)

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Here is a "normal" video with 25fps , 40ms delta between frames, and your command line works ok on this

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To increase the fps and add frames to your video you can add -vf fps before drawtext

-vf "fps=25,drawtext=text..."

There are some frames with overlapping text at 1,2 seconds because of drawtext "enable between" is inclusive

[slick zheng]

The timestamps in your input video do not have enough "granularity" to specify between seconds. Individual frames displayed for a long time (ie. it's effectively a very low fps video)

# timecode format v2
0
8360
17480
26080
33640
41600

Here is a "normal" video with 25fps , 40ms delta between frames, and your command line works ok on this

# timecode format v2
0
40
80
120
160
200
240
280

To increase the fps and add frames to your video you can add -vf fps before drawtext

-vf "fps=25,drawtext=text..."

There are some frames with overlapping text at 1,2 seconds because of drawtext "enable between" is inclusive

oh this is key point, I try this and solved, thanks.
BTW, I find another way is, first re-encode concated video, then use re-encoded video to do the draw text, I think it's same reason.