Video Compression Basic Concepts

The key to video compression is manipulating the human brain. If we consider transmission of raw video streams, it is simply impossible to match up to the current demands of market and available data transmission technology. Hence, compression and transmission of “relevant data” is extremely critical.

For instance, a raw video transmission may be around 150 Mbps, which is too high for distribution mediums. Conventional compression techniques reduced this to around 45 Mbps, which was also impractical. Without compression, a 2 hour digitized NTSC video would require roughly 100 GBs, which is simply unfeasible. This would require a transmission rate of 45-120 Mbps!

Rise of MPEG

The MPEG group was formed to tackle this problem. Three primary MPEG standards developed over time are:

  1. MPEG-1: Video storage on CDs. Delivery data rates of ~1.5Mbps.
  2. MPEG-2: Offers 50:1 compression of raw video. Used in DVDs, HDTV and DVB-S(Cable Dish Connection). Delivery data rate for HDTV is 19.39 Mbps, compared to 800 Mbps uncompressed.
  3. MPEG-4: Currently most popular video encoding standard. MPEG-4 later merged with H.264.