Choosing the right video codec

Video compression. Its a subject that can strike fear into the hearts of many well meaning individuals. Over the last few days I have been lucky enough to have been playing around with such things, as I try to prepare some of my videos for placement in the Eye of the Sky website. There are many problems that arise when compressing videos. What codec or container to use? What compression settings would be most optimal? What formats would be best supported by visitors? All important questions when it comes to compressing your videos for the web.

1. What codec to use?

This is one I got stuck on for quite awhile. There are many derivatives of MPEG4 that looked promising, as well as Flash Video, and also the unappealing option of using Windows Media. The three main codecs I decided to fully look into were DivX, FLV and Quicktime's H.264.

The one tricky thing about testing these out were that the sheer amount of time it takes to compress High Definition content down into smaller web formats can sometimes be ridiculous, especially trying to achieve said work off a laptop. Also another problem that arose is that the implementations of compressing videos through these formats is fairly closed - you have to pay money for a lot of the compressor programs. DivX has a free compressor in the form of Dr. DivX which I tried, while for the Quicktime you must upgrade to Quicktime Pro or use Final Cut to compress the videos down. I finally decided on using Quicktime's H.264 codec, as it offered a good balance between quality and file size. Although the results were comparable to DivX, I felt that Quicktime was slightly more industry standard.

2. What compression settings would be optimal?

Well you can't have your cake and eat it too. Its hard to get a good balance between quality and file size, so I decided for each video to output two different versions for different internet connection speeds. The first is a smaller 400x300 ish file would be suitable for dialup type speeds, and the other being a 720P version for fast internet speeds. Its best to optimize the video for steaming, and also to set a bitrate that will give the required file size. I found that around 2500kb/s was good for the 720P version, and 500kb/s for the 400x300.

3. What formats would be best supported by visitors?

This is a slightly trickier one. With the advent of YouTube, almost everyone has Flash installed in some flavour on their system. Because of this Flash Video probably has the best support out of all the codecs. Another one with a high uptake is Quicktime, which is used for a lot of the film trailers on the web, as well as being the industry standard for Digital Video files. One of the least supported codecs I imagine would be the DivX one, which is one of the main reasons I shied away from using this codec. It probably offers one of the best compression qualities, but with less user base and a spyware supported codec I found it hard to choose this format.

The Winner : Quicktime H.264

With good user support and a good compression scheme, Quicktime came out as the winner. Although I dislike the openness of all three main codec compressors, H.234 is a fairly open standard for both the Digital Video and Broadcasting industries. Now I just have to standardize the compression settings and squash the video files down to a respectable size. Which might take some time.