Monday, April 20, 2009

Video Conversion… SUCH A PAIN!!!!! The basics

Alrighty, its been a while since my last post. However I’m going to delve into the world of video encoding/transcoding. This is a pretty lengthy and complicated topic so I’ll try and make it as digestible as possible.

To start with, everyone has noticed that at the end of video files are extensions like .AVI .MP4 .MKV .MOV .WMV. However these are not really the actual video formats. These are just containers that hold the actual video file along with an accompanying audio file and in some cases additional files besides audio and video. These two or more files are held in the container file. So inside the .AVI file one should find a video and audio file. The files were muxed together by a program into the .AVI container file.

.AVI is one of the oldest containers, having originally been developed my Microsoft, its full name is actually the “AUDIO VIDEO INTERCHANGE”. Within this container the video file and audio files can actually be a multitude of formats. The audio can be anything form .AAC to .MP3/.MP4/.OGG/.FLAC. The same goes for video which can be .MPG/.MPEG/.DIVX/.XVID etc.

With the .AVI container being as old as it is, it actually has some limitations to it. For instance, it can only hold two items in it, a video and audio. Say you wanted to have a video and 2 audio files, each in a different language, it would be impossible, and more so, if you wanted to add a subtitle file your out of luck. With .AVI it is also incompatible with some of the newest video formats such as H.264/X.264. As such its loosing its relevance slowly but surely.

To deal with the situation, there are newer containers such as .MP4 and .MKV to the rescue. .MP4 is fully compatible with H.264/X.264 and .MKV having the ability to have multiple video files, audio files and subtitle files on one container!!!!! Basically more than two at a time.

.MKV created by the Matroska Foundation is a technological marvel and is completely open source (which means it was developed for free and is available to use for free) However the number of devices and programs that support it is near zero. However with the latest news from the format front saying that DIVX has chosen .MKV as the new container standard for their wildly popular video format due to it greater abilities, more devices will emerge with support for it.

Devices such as the PS3 and XBOX 360 that are fully DIVX certified will have to update their firmware to support the new DIVX standards and stay fully DIVX certified. So with time there will come support for .MKV on more devices, but for the moment all DIVX devices are only able to see DIVX video if it’s encoded in a .AVI container.

So in all there are way to many video formats and standards to cover in any one post. However I will cover the most useful and popular ones that are of the most benefit and the best programs to do the Video Encoding Job!!!