I don't want to use a player like vlc to speedup the playback. I want to actually speedup playback in the original file; I want the video to be played 2 times faster.
5 Answers
mencoder has a -speed
option you can use, e.g. -speed 2
to double the speed. It's described in the man page. Example:
mencoder -speed 2 -o output.avi -ovc lavc input.avi
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2
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2Worth noting that it works with
-ovc copy
, i.e. with no quality loss. Nov 18, 2020 at 10:01
After doing some research on this I found that the following command line option works well with ffmpeg:
ffmpeg -i input.mp4 -filter_complex "[0:v]setpts=0.5*PTS[v];[0:a]atempo=2[a]" -map "[v]" -map "[a]" -c:v libx264 -c:a aac output.mp4
First install ffmpeg.
setpts
is for video speed (.5 means twice as fast).atempo
is for audio speed (2 means twice as fast).The native FFmpeg AAC encoder used to be considered experimental, but this is no longer the case. If your ffmpeg is old, you will need to add
-strict experimental
to enable this encoder (the console output will mention this if you don't).Control video quality and encoding speed with
-crf
and-preset
as described in FFmpeg Wiki: H.264 Video Encoding Guide. Or just use the defaults if it looks acceptable to you.Control audio quality with
-b:a
as described in FFmpeg Wiki: AAC Audio Encoding Guide.
Reference: FFmpeg Wiki: MP3 Audio Encoding Guide.
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I've had the best results with this one. A variation on it:
ffmpeg -i input.mkv -c:v libx264 -crf 31 -c:a aac -b:a 64k -movflags +faststart -filter:v "setpts=0.25*PTS" output.mkv
. After ffmpeg was finished I opened it in avidemux and saved it immediately to fix the video duration and remove the audio.– rkokJul 29, 2022 at 10:12
slowmoVideo is able to speed up and slow down video
slowmoVideo is an OpenSource program that creates slow-motion videos from your footage.
But it does not simply make your videos play at 0.01× speed. You can smoothly slow down and speed up your footage, optionally with motion blur.
How does slow motion work? slowmoVideo tries to find out where pixels move in the video (this information is called Optical Flow), and then uses this information to calculate the additional frames.
First download and install the program. When it is loaded go to File > New and select your video file.
With your video loaded draw you curves (by clicking on an empty area) to describe how the video should speed up and slow down.
When you have finished go to File > Render (Ctrl + R) and choose a directory to save your video
openshot is a movie editor in linux. you can download and install it free: openshot .
then you must go clip properties and speed tab, then you can change speed of your videos and export them
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Please add further details to expand on your answer, such as working code or documentation citations.– Community BotSep 2, 2021 at 10:31