High Efficiency Video Coding (HEVC) is the latest buzzword in the video compression. HEVC envisions to attain the same visual quality as H.264/MPEG-4 Advanced Video Coding (AVC) with just 50 % of the bit rate requirement of current video standard (H.264/MPEG-4). Two to ten time increase in computational complexity is permitted. HVEC relies on VLSI and parallel computing to achieve the 'bit rate reduction' feat. There is no paradigm shift in the way video compression is carried out. Instead HEVC employs computationally intensive but compression efficient algorithms. Reference [1] is suited for enthusiasts and [2] for researchers.
In an MPEG video encoder, video is divided into frames, slices, macroblock and block. Block is the smallest unit that contains 8x8 pixels. MPEG exploit temporal (literally time; frame-to-frame) and spatial redundancies (like JPEG). Because of this very high compression ratio is achieved. To improve compression, MPEG uses a concept of motion vector. It employs Discrete Cosine Transform (DCT). Redundancy removed video is encoded by Huffman coding (popular variable length coding technique) to form bit stream. Importantly MPEG specify the format of compressed video only. Encoding the video and implementation of hardware is left to the manufacturers.
In HEVC block size varies from 4x4 to 64x64. Here also temporal and spatial redundancies are exploited. It employs DCT as well as Discrete Sine Transform (DST). Instead of Huffman coding, computationally intensive arithmetic coding is used (specifically CABAC). HVEC gives emphasis for parallel computing and data loss resilience (for video streaming over the networks).
Arrival of HVEC can make following implications. It will be a great news for video technology enthusiasts. VLSI technology researchers will come out with lot of architectures to implement HEVC in hardware. Thus there will be spike in research publications. Top technology companies may come out HEVC products and display in tech-expo. Technology magazine may give wide coverage for HVEC enabled products. Manufacturers will aggressively advertise the products and tech-savvy consumers will buy the product without bothering about the cost.
The real test of the HEVC technology is common man's acceptance. Common man behaviour is highly unpredictable so as the market. We have an irresistible to urge to predict. Lot of pundits air their predictions in media and fail miserably. For example, ten years ago in India when retail market was thrown open to big companies pundits predicted end of mom-and-pop shops. Today e-tailers are killing the big super markets and small mom-and-pop shops stays on. So, it is wise to keep mum and be deaf (to pundit's views) and leave the rest to time.
References
1. Mahsa T Pourazad, Colin Doutre, Maryam Azimi, Panos Nasiopoulos, "HEVC: The new gold standard for video compression: How does HEVC compare with H. 264/AVC?," IEEE Consumer Electronics Magazine, vol. (1), no. (1), 2012, pp. 36-46.
2. Gary J. Sullivan, Jens-Rainer Ohm, Woo-Jin Han, and Thomas Wiegand "Overview of the High Efficiency Video Coding (HEVC) Standard," IEEE Transactions Circuits and Systems for Video Technology, vol. (22), no. (12), Dec. 2012, pp. 1649-1668, 4 MB PDF
