hello,

is ti possible to reverse (play backwards) a video? is there an effect for this?

cheers

I use avidemux (selecting an avidemux filter) to reverse a video (but not the audio).

And then drag the reversed video into kdenlive.

This isnt possible. I have searched the forum for this too, and there seem to be many people asking for this feature. It would be nice if it were to be implemented. Using Avidemux is a way to reverse, but it is cumbersome if you have a lot of clips to be reversed.

> Using Avidemux is a way to reverse, but it is cumbersome if you have a lot of clips to be reversed.

I am not trying to discourage the wish to reverse videos in kdenlive as a desired feature

.... but if one is in a hurry, then I do note that one can create scripts with avidemux. I have not tried reversing multiple clips in a script with avidemux, but it should be possible. I note avidemux man page: http://www.linuxcertif.com/man/1/avidemux/

I should also note there is an old thread on this subject:
http://www.kdenlive.org/forum/once-again-playing-clips-backwards-reverse-negative-speed

As noted in the previous post thread link, the melt command can also be used to reverse a video.

I also noted same stated here on mltframework.org on answering MELT questions:
http://mltframework.org/twiki/bin/view/MLT/Questions#How_to_reverse_a_movie_e_g_have

I confess since avidemux works for me, I've never tried to reverse a video from the command line before (where I assume if one has MANY videos such as tubnome noted) one may wish to compose a script or very large command.

BUT since it was noted that MELT could reverse a video, I took a brief (and very rough) look at MELT :

To convert just one video (at 640x480 resolution, where the input video is called input.avi, and the output video called reversed-out.avi, I found the following worked for me (albeit it was not perfect and needs tuning):

melt input.avi -consumer avformat:images%05d.jpg s=2560x1920 real_time=0; melt -group in=0 out=0 `ls -r` -consumer avformat:reverse.avi qscale=0.01 real_time=0

I do not know the best values for s=WxH, nor do I know the best settings to tune the other values.

But if one can get that melt command line tuned, then putting it into a loop to process many videos in a single directory should not be too difficult.

Here is another way that does not require encoding:

melt -profile atsc_720p_25 framebuffer:myvideo.mp4 reverse=1 -consumer xml:myvideo.mlt

Now, load myvideo.mlt as a clip.

It is important that you choose a profile that is the same as your project. With latest versions of melt, 'melt -query profiles' gives you a list and 'melt -query profile=atsc_720p_25' gives you detail about one profile.

> Here is another way that does not require encoding:

> melt -profile atsc_720p_25 framebuffer:myvideo.mp4 reverse=1 -consumer xml:myvideo.mlt

> Now, load myvideo.mlt as a clip.

> It is important that you choose a profile that is the same as your project. With latest versions of melt, 'melt -query profiles' gives you a list
> and 'melt -query profile=atsc_720p_25' gives you detail about one profile.

Thanks ! That works nicely. It was a bit tricky (for me) thou to figure out how to ensure I had identical profiles ! :) Without identical profiles one ends up with horrible pixelization !

@ddennedy: "Here is another way that does not require encoding:
melt -profile atsc_720p_25 framebuffer:myvideo.mp4 reverse=1 -consumer xml:myvideo.mlt"

For me, reverses video, but audio is silent. Latest SVN via Builder Wizard.

I have no interest myself in reverse audio. But its easy to do:

sox old.wav new.wav reverse

@AlexK The audio is silent by design (not implemented yet).