Monday, April 27, 2015

The challenges facing a new codec

I was asked recently to comment on how easy or difficult it might be to introduce a new video compression codec. Here's a summary of my opinion - you can read the full article by John Moulding here.

At present, the market is dominated by standards-based and open source solutions, including H.264 / AVC, VP8, HEVC and VP9. What challenges might be faced by a new entrant to the market?

1. Interoperability: One of the key motivations for the development of standards has been interoperability. Streaming provider X needs to be compatible with playback client Y. Building a critical mass of support for a new codec requires widespread adoption of encoders and decoders that interoperate with each other.

2. Performance: The development of standards such as H.264 or HEVC involved rigorous and thorough testing using agreed protocols for measurement of quality, bitrate, computational requirements, etc. Performance testing needs to be repeatable, such that multiple organisations can check performance and reach the same conclusions.

3. Intellectual property: An open source or standardised solution provides a degree of transparency about who might own intellectual property that is used in a compression solution. For example, implementors of the H.264/AVC standard can take a license to several hundred patents that may be essential to the standard, via the MPEG-LA patent pool.

4. Hardware support: When you play back or stream a video on a consumer device such as a cellphone or tablet, the computationally intensive process of decoding video is assisted by dedicated hardware, enabling smoother playback and better battery life. Support for existing formats such as H.264 and VP8 is built in to chipsets, operating systems and protocols.

A new codec technology has to overcome many hurdles if it is to be widely adopted. However, I am always interested in genuinely new and disruptive approaches to video compression. Is there a challenger out there to the 25-year-old codec model that has been the basis of video compression standards from MPEG-1 to HEVC?