Opened 4 years ago
Closed 4 years ago
#8721 closed defect (invalid)
-f concat hardcode input at 25fps. Impossible to set to something else.
Reported by: | grisk | Owned by: | |
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Priority: | normal | Component: | undetermined |
Version: | unspecified | Keywords: | |
Cc: | Blocked By: | ||
Blocking: | Reproduced by developer: | no | |
Analyzed by developer: | no |
Description
Summary of the bug:
There is no option that let you change the input of the command -f concat -i "{txtPath}" to something other than the default 25fps.
Here are my tests and the results:
# -r before "-f concat" : Override all duration from file. Its just like using a static fps
# -vf "fps=X" : Fake final fps, it will keep very few frames in the final output.
# -r after -i "{txtPath}" : It appear to work, but its start to have problems after 60fps.
# -filter:v "fps={fps},setpts={speed}*PTS" : It encode correctly after the video is encoded at 25fps. So if there is a duration smaller than 25fps, it will delete those frames.
Attached is a python script that make it very easy to test it.
How to reproduce:
% ffmpeg -y -f concat -i "{txtPath}" -c:v libx264 -crf 1 -pix_fmt yuv420p -r 120 "{out}" % ffmpeg -y -r 120 -f concat -i "{txtPath}" -c:v libx264 -crf 1 -pix_fmt yuv420p"{out}" % ffmpeg -y -f concat -i "{txtPath}" -c:v libx264 -crf 1 -pix_fmt yuv420p -filter:v "fps=120,setpts={speed}*PTS" "{out}" % ffmpeg -y -f concat -i "{txtPath}" -c:v libx264 -crf 1 -pix_fmt yuv420p -vf "fps=120" "{out}" ffmpeg 4.2.2-1ubuntu1~18.04.york0 built on ubuntu0.18.04.1
Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.
Attachments (1)
Change History (3)
by , 4 years ago
Attachment: | fffmpeg.py added |
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comment:1 by , 4 years ago
concat does not hard-code any frame rate, it uses the frame rate of the files you concatenate. Use a format that supports timestamps rather than individual image files and you will be fine.
comment:2 by , 4 years ago
Resolution: | → invalid |
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Status: | new → closed |
Version: | 3.4.6 → unspecified |
Python script