[HTC EVO 3D] panamaniac:
Yes, Handbrake will keep the files in side-by-side. Following the instructions in the knowyourcell linke, you'll typically be converting a MKV into an MP4. But your Gallery app is smart enough that when you watch the video and hit settings-->3D, it'll merge the screens.

HOWEVER, I was never able to get the Handbrake solution to give me good audio. So I tried Freemake and it was very successful and a little faster I think. Here's my writeup:

****TWO PRELIMINARY NOTE: (1) Please note that this is only to be used for 3D video files that you OWN THE RIGHT TO USE. (2) This guide will be most useful to those trying to convert a .MKV file, which is a type of 3D video file that is always (in my experience) "side-by-side" (technically called HALF side-by-side or half-sbs) meaning if you were to play the file on a non-3D device it would simply show two identical videos running side by side. It's THIS kind of 3D file that I've had success with so far; I've had a harder time finding solutions with "top/bottom" (also called "over under" 3D files where one image is ABOVE the other.******

Ok, now that that's out of the way, let's get started

For Starters, You'll Need:

A) The 3D file you want to view on your HTC Evo 3D

B) A connection to the internet

C) Your HTC Evo 3D (of course )

D) Your USB cable to connect your EVO 3D to your computer (this came with the phone)

Next, Your computer will need some Video Conversion Software:

DOWNLOAD: I've heard of several different programs working, but my favorite by far has been Freemake Video Converter, which you can download on your computer by going here by clicking the green "DOWNLOAD" button in the top-right corner of the page. (Once you click the DOWNLOAD button, you'll be sent to CNET.com, a very trusted tech news and download site, so you know it's a safe place to download a file!).

Launch: Launch your freshly-downloaded Freemake Video Converter.

We're halfway done!

Find Files to Convert: Now that the program is open, click either the "+ Video" or "+DVD" button in order to browse your hard drive for the 3D movies you want to make viewable on your EVO 3D. Double click on them to add them to your queue. (Remember, these should be side-by-side 3D videos--probably with file extension .MKV)

Notice how each file you double click on simple gets added to the list (queue) in the big white middle of the program. So Freemake automatically builds a queue and will let you convert ALL your files with one click later on! However, if you just want to convert one file, find it, double click it to put it in your queue, and move on

Once you've lined up your files, go to the bottom of Freemake and click "To Android."

Click the drop-down menu under "Preset", go all the way to the bottom and click "Add Your Preset" (or just click the green plus sign)

Name your new preset "Evo 3D" or something you'll remember, then apply these settings:

- Frame size: size up to

- Width: 960

- Height: 540

-Adjustment: Original

-Video Codec: H.264

-Frame Rate: Original

-Bitrate Type: Custom

-Bitrate (Kbps): 1500

Then for audio, click the "Custom Audio" button and use these settings:

-Audio Codec: AAC

-Channels: Stereo

-Sample Rate: 48000 Hz

-Bitrate: 256

Click OK and it should save your new preset. Now choose the file path that you want to save your new files to (note: you can't change the file names of your converted files at this point). Note that this conversion will leave your original file INTACT and in their ORIGINAL place and simply make converted COPIES.

Click CONVERT and THAT'S IT! You're Done! Check the status bar, but after about 20-50 minutes a regular movie should be done.

Now that conversion is complete:

-Plug in your Evo 3D, access the SD card from your PC, and copy/paste the newly converted file onto your SD card (What most of us do is create a new folder on the SD card called "Video" and then place all our converted files here).

-Use GALLERY to watch your movies--it should find the files automatically. When watching, it will usually start by playing the file as two images side by side. Just make the video fullscreen, THEN hit the options button and choose "3D", confirm, and there you go!

**NOTE: Not all of the above steps/settings may be necessary, and there are probably some great ways to improve it...but this way should get you a pretty good, very cool 3D video on your phone! Although don't forget the end result can never be better than what you start with!**