All video may look the same and sound the same, but it actually comes in many flavors, formats and compression systems (codecs). Premiere Elements is built around a DV-AVI workflow. (DV-AVIs are AVI files that use the DV codec.) This means that DV-AVIs flow easily through it and place the least strain on the program and, ultimately, your system. Not all AVIs use the DV codec, and many (such as video from still cameras) can cause real problems for Premiere Elements.
A good rule of thumb is that, whenever possible, you should use DV-AVIs as your video source.
A number of free or low-cost programs will convert your files.
Premiere Elements - Premiere Elements, especially current versions, can often do an excellent job of converting. To use it, open a new project (Use the DVD/Hard Drive Camcorder project setting if you're converting MPEGs to DVD files), import your video and place it on the timeline. Then, with the timelline selected, go to File/Export/Movie. The resultant AVI should work perfectly in any Premiere Elements project.
If you don't get the quality you need or if the program simply can't handle the file format or codec, here are some other options:
MPEG Streamclip (free at http://www.squared5.com ) - A great tool for easily converting MPEGs and VOB files (DVD video files). To use it, open the file with MPEG Streamclip and then open the AVI/DivX Exporter window from File/Export to AVI.
For Compression select the Apple DV/DVPRO_NTSC (or DV PAL, if appropriate) codec. For Field Order select Lower Field First. Change the default sound settings from MPEG Layer 3 to Uncompressed.
If you have widescreen footage click on the Options at the top right. Leave the Scan Mode as is but change the Aspect Ratio from 4:3 to 16:9. If you would like to save these settings, click on the Presets button at the bottom left then click on the New button to name and save your settings. The next time you run MPEG Streamclip, you can go directly to the Presets button and Load your saved settings.
Click on “Make AVI” and choose a folder and filename for your DV-AVI file.
Super (free from http://www.erightsoft.com/SUPER.html ) can convert almost any video format to almost any other video format. It's newest version outputs both PAL and NTSC DV-AVIs.
To use Super, set the Output Container drop-down menu to DV -- and leave everything else at its default setting. (Although, if you are using PAL video, ensure that Video Scale Size is set to 720:576.) Drag the video you want to convert to the area just below the Output specs and click Encode.
Finding the download link on its messy web site is a bit tough though. But you can find it near the bottom of this page
Windows MovieMaker - It’s right on your computer, and it handles a wide range of files. It’s particularly good for converting still camera video to a format Premiere Elements can work with.
To convert a video into a DV-AVI with MovieMaker, simply import it into MovieMaker and drag it to the MovieMaker timeline. Then:
From the Main Menu select File/Save Movie File A dialog will open - Select ‘My Computer’ and press the Next button.
On the next screen you can name the new file and select/browse to a folder to put the file in (remember where you put it because you will need to browse to the file in Premiere Elements to import to you project). When you have named the file and selected the location press the Next button.
On the next screen, click the link that says Show More Choices. There will be three radio buttons to choose from. Select No. 3, Other Settings and, from the drop-down menu, select DV-AVI.
NOTE: Windows Live MovieMaker, the new, online version of MovieMaker included with Windows 7, will not output DV-AVIs. Fortunately, the "classic" Windows MovieMaker 2.6 is still available on the Microsoft site. You can find it here:
Quicktime Pro ($29 from Apple) - A great tool to own if you use a lot of MOVs (Quicktime) as source files. It not only converts MOVs to DV-AVIs but also includes some basic video editing functions.
VirtualDub (free from http://www.virtualdub.org ) – This terrific tool should be on everyone’s computer. Less a conversion tool than a video processor, it will make many AVIs (including Type 1 DV-AVIs) compatible with Premiere Elements as well as converting many other file types. Converting is as easy as opening the file in VirtualDub and doing a Save As to create the new, freshly-processed file.