Converting HD (or DVD) clips to AVI with Avidemux (Mac & PC)


NOTE: This tutorial is one nice (and relatively easy) way to convert MKV files for editing. Another way is using VirtualDub and an Avisynth script (Windows only).

This tutorial is an extension of an Avidemux tutorial I have on the Foolish Passion fan video forums. I’ve used version 2.4.4 (and old version) of Avidemux because a newer version (2.5.2) crashes and freezes when dealing with MKV files, on both Mac and PC.

First we’re going to go through the converting of a genuine HD file (MKV format) to an AVI that is suitable for editing. This MJPEG AVI file should work with most video editing apps, but do small tests first to make sure. (It will even work okay on Macs, though you will have to render it in Final Cut’s timeline. However, Mac users should check out this tutorial on the Foolish Passion forums because it does give excellent quality with no rendering needed in Final Cut.) [Update: I found that when I had the AMV app installed on my PC, my video editing software was more apt to recognize these MJPEG AVI files.]

If you wonder why I specify this kind of AVI, or if you want to know more about what I’m talking about when I say we’re editing in “genuine” HD, please read this tutorial first (link opens to new window).

Converting an HD MKV file to an AVI suitable for editing.

Download and install Avidemux (free, for Mac, PC, and Linux, and remember, you may need to get the older version 2.4.4). Open Avidemux and click on the “Open” icon and locate the MKV file that you want to convert to AVI. The first thing that will happen is that Avidemux will process the “Matroska images.”

Avidemux will ask if you want to use “safe mode” but I always click on “cancel.”

Do you want to get the Index up to date? Yes you do. Click on “Yes.”

Now you get to the actual interface of Avidemux. On the left side are areas for customizing both video, audio, and choosing video format (AVI, MP4, etc).

At the bottom of Avidemux you see there’s two icons (circled in red) with an “A” and a “B.” These indicate an “in” (or start) and “out” (end) points. You don’t have to use these—you can do nothing and just convert the whole movie or episode over to AVI. But if you just want to select a small scene, you can do that too. Scroll through the video and when you get to the spot where you’d like your clip to start, click on the “A” icon. Then scoll to where you want the clip to end. Click the “B” icon. As you see from the screenshot above, Avidemux makes little marks to indicate where you’ve marked “in” and “out.”

Now you’re ready to prepare your video for conversion to AVI. Click on the top drop down menu under “Video.” Select “MJPEG (lavc).”

Under “Video,” click on “Configure.” Raise the quality to somewhere between 90-100. Click OK.

Under “Audio,” select “WAV PCM.” (Please note that sometimes with HD files made in Avidemux, audio will not sync up right. Usually this is not a big problem for making fan videos because we don’t typically use audio.)

Under “Format,” leave it at “AVI.”

Click on the “Save” icon at the top left of Avidemux and then choose a place to save your file, and also make a file name. BE SURE TO ADD the “.avi” extension at the end.

Wait as the file converts over to AVI. NOTE: A full hour of an HD MJPEG AVI file can be several GBs in size. (Usually for me, a 45 minute video takes up about 5-6 GB or more of space.) This is normal and expected.

Technical note: When Avidemux makes file sizes larger than 4 GB, it automatically splits the file into separate parts. The first part is given the “avi” extension, but subsequent parts have the “avi01” “avi02” extensions. You need to rename these files so they become AVI again.

You can see from this screenshot that I’ve renamed my POTO clips with “MJPEG1.avi” and so forth. But I have yet to rename my “Law Abiding Citizen” clips.

Editing in HD: When you’ve made your genuine HD AVI files, you can now start editing them in your video software. Follow this tutorial for more info on how to set up your software to edit in real HD quality video. (Tutorial is for both Mac and PC.)

Another technical note: HD files made in Avidemux are often a little washed out and require that you increase the contrast and darkness in your video editing software. Also, there will be some “blockiness” in the video picture. It’s not really bad and certainly the overall quality of the video is better than what you can get from a DVD. Also, as noted earlier, sometimes the audio does not sync correctly. And you may have four audio tracks when you open the file in your video software.

IF YOUR MJPEG AVI FILES DON’T OPEN IN YOUR SOFTWARE: *gulp* This happens sometimes. It’s a hassle, but what I’ve done is re-encode the clips in MPEG Streamclip, following this tutorial. (Follow the instructions for converting an H.264 MOV to MJPEG AVI, but instead of starting with a MOV, you’ll start with the AVI files you made in Avidemux.) Surprisingly, the quality doesn’t have to suffer too much. I made this video using clips which had to be re-encoded.

Adjusting a “super widescreen” video for HD editing.

If your show or movie is in the “super widescreen” 2.35:1 aspect ratio, I recommend that you add letterbox bars back into the video.

As you can see, this video is suuuper wide, not the typical 16:9 widescreen size. As this aspect ratio tutorial explains, it is in the 2.35:1 aspect ratio. When you see a 2.35:1 movie on DVD, the DVD adds black letterbox bars at the top and bottom of the video so the whole thing fits into the 16:9 frame size. But when this movie was converted to MKV, the black letterbox bars were either omitted or removed.

When you set up your editing software to edit in HD, it’ll expect you to edit files in the 16:9 aspect ratio, which for HD is either 1280x720 or 1920x1080. So, you need to pad this suuuper wide video so it’s got one of those standard HD sizes. You DO NOT want to stretch it out or simply resize it, because that will distort the video so everyone looks too long and skinny. Padding with black bars is the only way to go.

Under “Video,” click on “Filters.”

Highlight the “Transform” tab and select “MPlayer resize.” The “Resize” window will pop up. Write down the number of the “Height” (in this case it’s 536, but it could be some other number). Click “Cancel” to get rid of the Resize box.

Because this is going to be a 1280x720 HD video, you need to pad that 536 number so it’s 720. The difference between  720 and 536 is 184. And half of 184 is 92. So you’re going to add a black bar of 92 pixels at the top and bottom, to restore the video back to the true HD size of 1280x720.

Still under the “Transform” tab, click on “Add black borders.” Add the numbers “92” (or whatever numbers you need to make the video add up to 720 height) to the Top and Bottom border text boxes.

Click “OK.”

Then click “Close” to get rid of the filter menu.

Now finish converting the video to MJPEG AVI following the tutorial instructions above.

NOTE: If the MKV file you’re using is supposed to be the larger HD size of 1920x1080, do the math adjustments so the height of the video ends up as 1080.

Converting a DVD rip to MJPEG AVI:

The MJPEG AVI files made in Avidemux will work with most video software, but DO TESTS with small clips first to make sure.

Locate the DVD rip on your hard drive. Select a VOB file. (Some VOB files will not have anything useful in them. Poke around until you find one that is about 15 minutes in length or 1 GB in size.)

Yes you want to index it.

Yes, you want to join all the VOB files (also known as mpeg) that make up an episode or feature film. Click “Yes.”

Wait while it indexes.

Do that. Select the Main audio track.

Like when you convert MJPEG for HD, select MJPEG with a quality of 90-100%. IIf you are hurting for disk space, you can go a little lower and see how it looks. (Again note that with MJPEG AVI, you will need plenty of disk space. Estimate an average of 5-6 GB per 45 minutes of footage or possibly less if you lower the quality setting.)

Now you’re going to have to resize the video, because as it is, it looks distorted (in this case, too long and skinny). Click on “Filters” under “Video.”

Select the “Transform” tab, and click on “Resize.” This is where you need to know the aspect ratio of your DVD. If the original movie or show has a more boxy frame, it’s fullscreen or 4:3. If it is more rectangular, its’s 16:9 widescreen. (See this tutorial for more info.)

If your DVD is in the 16:9 aspect ratio, use these settings:

If the Height number reads 480, change the Width to 856. If the Height number reads 576, change the width number to 1024.

If your DVD is in the 4:3 aspect ratio, use these settings:

If the Height number reads 480, change the width number to 640. If the Height number reads 576, change the width to 768.

Make sure that “Lanczos3” is selected.

When you’ve done all of that, click “OK.”

Like when you convert HD clips to AVI, select “WAV PCM” for Audio.

Follow the HD tutorial above for saving the AVI file, naming it, and exporting it out of Avidemux, because the process is identical.

FINAL NOTES: This tutorial (using Avidemux) is just one way to process MKV files. If you want to learn a better way (but which has a higher learning curve), consult the guide (for Windows only).

OTHER WAYS TO CONVERT A DVD RIP: If the MJPEG AVI files that Avidemux makes do not open in your video software, I recommend trying the MPEG Streamclip method instead. (This is for DVD rips only, as I can't get MKV files to open in the Windows version of MPEG Streamclip.)

Visit  the Foolish Passion fan video forums for more tutorials for HD, for Mac and PC software. (Free membership required to view some tutorials.)