This article explains what video compression is and why it is needed. It also explains what a web video codec is and why they are needed.
When using digital video file size is an important consideration because video files tend to take up a lot of storage space on your hard drive. This problem also affects the online services such as youtube or metacafe as even they do not have infinite storage space. So, we need to reduce the size of our video file when we want to upload them to the web. The technique we use to reduce the file sizes is called “compression,” or video compression.
With plain text files size is not so important as the files are full of spaces that can be compressed easily. You can get a high compression ratio, up to 80/90 percent, for text files. However with video and images it is harder to get a good compression percentage as there are few spaces in the files.
This is where video codecs come in. They are specialised pieces of software, or hardware devices, that compress and decompress your video. The term codec stands for compression/decompression.
This video tutorial is an excellent introduction to video compression for the web:
The keys points made in the video are that:
- DVD type video formats are not suitable for web playback as the file sizes are too large
- Formats/Codecs like H.264 and Flash are suitable for the web
- To retain quality always go from the larger file sizes/formats to lower ones