Play two videos in sync as well as having seek in sync

Question

I have two different videos. Now here's the thing, they have the same lengths, and they are related to each other. Is there a way that I can play these videos on at the same time using VLC and also have a unified seek bar, so that the times are the same for both, since one video is dependent on the other.

Answer 1

The old version of VLC was able to do this very well without any kind of scripting or add-on. To accomplish this simply open VLC 2 and select Media>Open Multiple Files. Inside the multiple file windows select add to add the first file. After this click on the, "Show more options," checkbox followed by the, "Play another media synchronously," checkbox at the bottom of the window. Select browse next to, "Extra media," to add the second file. Hit play and the two media files will play simultaneously with a single control window.

Answer 2

You can do this in VLC for mac (version 2.2.6 https://get.videolan.org/vlc/2.2.6/macosx/) using File > Advanced open file.

Answer 3

One way to achieve this is to use ffmpeg. If you have two or more videos you can just stack them horizontally, vertically or in a grid using ffmpeg and then play it as a single video file. Here is a snippet of how you would stack two mp4 files horizontally:

ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex hstack=inputs=2 stacked_output.mp4

Answer 4

You could merge the two video files together to achieve what you want. See questions like https://stackoverflow.com/questions/9293265/ffmpeg-2-videos-transcoded-and-side-by-side-in-1-frame

Excerpt command that can achieve it:
ffmpeg -i left.webm -vf "[in] scale=iw/2:ih/2, pad=2*iw:ih [left]; movie=right.mp4, scale=iw/2:ih/2, fade=alpha=1 [right]; [left][right] overlay=main_w/2:0 [out]" -c:a aac -b:v 3800k output.mp4

Answer 5

vlcsync - it syncs multiply vlc instances in background. After tried to find a solution, decide wrote my own. This is how the solution came about.

Features:

• play/pause/seek from any player
• tested on Linux/Windows

Note:

• Do NOT provide exactly frame-to-frame sync, but do it close as possible and applicable in many cases (see: Limitations)

Answer 6

I have recently solved it with mplayer and you can see the solution on superuser here: master-slave with mplayer

Answer 7

You can use AutoHotKey to achieve something similar though not perfect. I posted my answer to a question similar to yours here