How to play multiple videos side-by-side synchronized?

Question

I've got 3 videos, all 3 have the same time, same amount of frames, and they only differ in terms of encoding quality.

Now I need them to run side-by-side in synchronized fashion for evaluation purposes. Meaning when I press "play" BOTH! videos should start. Analogically for stop, forward, backward.

Anyone know any player capable of doing that? By that I mean playing more than 1 video side-by-side...

Platform: Win7

Answer 1

VLC on Windows (1.1.10 or later):

• Tools → Preferences
• Show Settings → All
• Click Advanced
• Uncheck "Allow only one running instance"
• Uncheck "One instance when started from file"

VLC on OS X does not provide the same set of options. You can however run multiple instances from the Terminal with open -a VLC.

Answer 2

google probably already told you, you could buy a couple proprietary software who could do that, but just in case : videocompare, tmpgenc, vidlord...

This one's free : http://forum.doom9.org/showthread.php?t=138430

(working download links at the end of the thread)

Untested because my wine setup is completely screwed right now. It doesn't do side by side but stacked playback (unless you have a very good lcd you won't be seeing the same thing by playing the same vid in two opposite corners of the screen anyway)

If you think you really need side by side you can use avisynth to do what zimmer said.

clip1 = DirectShowSource("C:\MyEncode1.foo", audio=false)
clip2 = DirectShowSource("C:\MyEncode2.foo", audio=false)
StackVertical(clip1,clip2)

(reference forum.doom9.org/showthread.php?t=139769)

You don't need to do an encode (wich would add its own encoding artifacts anyway), just make a project that would produce an encode of the two vids playing together and skip through the file.

Answer 3

I image you can use an AutoHotKey script to send a "Play" shortcut to all three players in a very short amount of time.

Whether they are able to start playing at exactly the same time is a different matter. Even if they are able to start straight away, I imagine there will be some fighting for the hard drive. Might want to make a RAM disk if this is an important evaluation.

Answer 4

If this is not something you do very often, I would use a video editing software like vegas to build one video with all of them showing.

Youtube video example of how to do that.

Answer 5

Many players will be able to output a picture of a single frame in the video.

You could choose multiple points in your videos to compare different types of image (clouds, smoke, trees, grass, motion are good for encoding comparisons) and take the same frames from each of your videos.

You can then make comparisons on a static image rather than trying to spot differences in motion. You can compare on a pixel by pixel basis if you want.

Ensure you don't use JPG as the output though as this is a lossy format and will introduce its own artefacts.