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I am new to ffmpeg and i am facing this error for more then 2 days. This ffmpeg command: !ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "xfade=transition={chosenTransition}:duration={transitionDuration}:offset=-1.5" -c:v libx264 -crf 18 -preset veryfast "{outPath}" I run that previous command 3 times in row where output of the previous command is input that is getting produced as 15360 timebase video i guess.

is giving me this error: "First input link main timebase (1/15360) do not match the corresponding second input link xfade timebase (1/90000)"

So when i merge two of my videos the output is video with (1/15360) timebase. Original videos has (1/90000) timebase.

Pls help what i wana archive is basicly multiple videos inside a folder called "clips" merge together using a random transition from xfade/ffmpeg.

On colab i tried all this ways:

!rm -rf chunks
!mkdir chunks
folderPath = '/content/clips'
videoOutput = '/content/test.mp4'
transitionDuration = 6

videoFiles = [f"{folderPath}/{f}" for f in os.listdir(folderPath) if f.endswith('.mp4')]
fromPath = videoFiles[0]
toPath = ''
outPath = ''
transitions = ['fade', 'wipeup', 'slidedown', 'circleclose', 'radial' , 'hrslice', 'hblur', 'smoothleft', 'smoothright']

for videoIndex, videoName in enumerate(videoFiles):
    if videoIndex == 0:
    toPath = videoName
    chosenTransition = random.choice(transitions)
    print('chosenTransition', chosenTransition)
    clipDuration = int((imageio.get_reader(fromPath)).get_meta_data()['duration']) - transitionDuration
    # !echo -i /content/clips/clip0.mp4 -i /content/clips/clip1.mp4 -filter_complex xfade=transition={chosenTransition}:duration=3:offset={clipDuration} dissolveVideo.mp4

    if videoIndex == len(videoFiles) - 1:
        outPath = videoOutput
        outPath = f'/content/chunks/chunk{videoIndex}.mp4'
    # !echo -i "{fromPath}" -i "{toPath}" -filter_complex "[0:v]xfade=transition={chosenTransition}:duration=3:offset={clipDuration},settb=1/19000[v0];[0:a][1:a]acrossfade=d=3[aout]" -map "[v0]" -map "[aout]" -c:v libx264 -crf 18 -preset ultrafast "{outPath}"
    !ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "xfade=transition={chosenTransition}:duration={transitionDuration}:offset=-1.5,settb=1/15360" -c:v libx264 -crf 18 -preset veryfast "{outPath}"
    # !ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "[0:v]settb=1/15360,setpts=PTS-STARTPTS[v0];[1:v]settb=1/15360,setpts=PTS-STARTPTS[v1];[v0][v1]xfade=transition={chosenTransition}:duration={transitionDuration}:offset=-1.5[vout]" -map "[vout]" -c:v libx264 -crf 18 -preset ultrafast "{outPath}"
    # !ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "[0]settb=AVTB [0v]; [1]settb=AVTB [1v]; [0v] [1v]xfade=transition={chosenTransition}:duration={transitionDuration}:offset=1" -c:v libx264 -crf 18 -preset ultrafast "{outPath}"
    # !ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "[0:v]xfade=transition={chosenTransition}:duration=3:offset={clipDuration},settb=1/15360[v0];[0:a][1:a]acrossfade=d=3[aout]" -map "[v0]" -map "[aout]" -c:v libx264 -crf 18 -preset ultrafast "{outPath}"
    # !ffmpeg -y -progress .progressinfo.dat -i "{fromPath}" -i "{toPath}" -filter_complex "[0:v]settb=AVTB,setpts=PTS-STARTPTS[v0];[1:v]settb=AVTB,setpts=PTS-STARTPTS[v1];[v0][v1]xfade=transition={chosenTransition}:duration={transitionDuration}:offset={clipDuration}[vout];[0:a]asettb=AVTB,asetpts=PTS-STARTPTS[a0];[1:a]asettb=AVTB,asetpts=PTS-STARTPTS[a1];[a0][a1]acrossfade=d=3[aout]" -map "[vout]" -map "[aout]" -c:v libx264 -crf 18 -preset ultrafast "{outPath}"

1 Answer 1


Firstly, there is nothing wrong with the timebase; ffmpeg can compare timebases, and generate new timebases.

Secondly, the problem is about different frame rates. if you use input frame rate settings

ffmpeg -r 30 -i "{fromPath}" -r 30 -i "{toPath}" ...

or use filter frame rate settings

ffmpeg -i "{fromPath}" -i "{toPath}" -filter_complex "[0:v]fps=30[v0];[1:v]fps=30[v1];[v0][v1]xfade=transition ...

or use same frame rate input streams, i.e. 30 frame per second, on your original command,

, ffmpeg will have no problems generating an output with fading transitions.

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