Digital Formats Explained.

Just like everything else in the world of computers, Digital Video (DV) has so many different formats that it's enough to confuse even a seasoned professional. Here, I'll try to explain a little bit about Digital Video.

In order to fit large amounts of data onto tape media, codecs are used for video compression.

A codec is what makes the magic happen. Here are some:

• H.261
• MPEG-1 Part 2
• MPEG-2 Part 2
• H.263
• MPEG-4
• MPEG-4 Part 2
• MPEG-4 Part 10
• VC-1
• DivX (proprietary) (uses MPEG-4 ASP)
• XviD (open source) (uses MPEG-4 ASP)
• H.264
• WMV

To make things even more confusing, the list above just refers to the codecs involved in encoding the video and not the wrapper...

The "wrapper" or "container" of your video file refers to what the extension of the file name is.

Common Wrappers:

• AVI (Audio Video Interleave) is Windows' standard multimedia container
• MPEG-4 Part 14 (known to you as .mp4) is the standardized container for MPEG-4
• FLV (Flash Video) is the format used to deliver MPEG video through Flash Player
• MOV is Apple's QuickTime container format
• OGG, OGM and OGV are open-standard containers
• MKV (Mastroska) is another open-specification container that you've seen if you've ever downloaded anime
• VOB means DVD Video Object. Guess what? It's DVD's standard container, and what you get when you rip a DVD.
• ASF is a Microsoft format designed for WMV and WMA—files can end in .wmv or .asf

To play a video file, your setup has to be able to handle both the actual video codec and the container. It's why you can try to play an AVI file and Windows Media Player laughs — the container was no problem, but it didn't have the right codec. Or conversely, even though an iPod could play back an H.264 encoded video, if it was wrapped up in MKV, it won't be able to read it.