Type 1 Video Coding

Type 1 Video Coding

From the very beginning MPEG realised that too many companies had invested in digital media technologies for MPEG to realistically target the development of unencumbered high-performance digital media standards. That wisdom has served MPEG well for many years thanks to the (internal) ability to integrate the best technologies and the (external) ability to provide licensing terms for packages of patents.

Does the value of that wisdom still hold today? the answer is definitely yes. We are nowhere in sight of the end point of compression not only because there is more fat to squeeze out of media but also because capturing – and corresponding presentation – technologies continue to improve yielding more bits/samples, more realistic colours, more brightness, more dimensions… Unless MPEG continues to provide standards yielding the best quality money can buy, someone else will do in its stead.

This does not mean that there is only one wisdom ruling the field. When version 1 of MPEG-4 was approved 6 years had passed since MPEG-1 had been approved. When AVC was approved 11 years had passed. When HEVC was approved 21 years had passed. If 20 years ago it was foolish to try and define an unencumbered compression standard, today, with many of the old patents expired it may be possible to put together what ISO/IEC call “Type 1 standard” that people can hopefully implement without the need to pay royalties. That this is a meaningful path to tread is shown by the increasing number of private companies bringing to market proprietary codecs, some of them claiming that their solution is “royalty free”.

In the second half of the 2000s I started raising the issue of MPEG becoming a body handling technologies that were fast maturing, even though the research area was still very vital and capable of producing significant innovations as we will see with the HEVC and 3D Audio standards. In July 2011 a Call for Proposals for Internet Video Coding Technologies was published. This CfP was seeking compression technology for video in progressive format with compression capability that substantially outperforms MPEG-2 and is comparable to AVC Baseline Profile. The intention was to develop a specification that would include an initial profile (the “Baseline Profile”) of Type 1, i.e. for which patent owners are prepared to grant a free of charge license and which may include other profiles that may be royalty-bearing (so-called Type 2).

The CfP also stated that “MPEG recognized, however, that a Baseline Profile may not be possible”, indicating that MPEG was aware of the difficulties laying ahead.

Two submissions were received at the following October 2011 meeting. One proposed to create a hopefully Type 1 standard by extracting the AVC Baseline Profile and making it a separate standard – called Web Video Coding (WebVC) – against which patent declarations could be sought. This was done but the result was not up to the expectations: a number of companies declared that they would licence their patents ar Fair, Reasonable and Non-Discriminatory (FRAND) conditions.

The second proposal was indeed about a process to develop a Type 1 video compression standard substantiated by a first video coding whose performance was still below the target set by the CfP. Still, because the proposal looked interesting, an exploration activity was started retaining the name Internet Video Coding (IVC). However, in the next two years substantial performance improvements were not reported.

To break the stalemate a revised version of the July 2011 CfP was published again in April 2013. Only one response from Google was received that proposed yet another approach at the development of a Type 1 standard. Google proposed their VP8 video codec that they licensed free of charge.

While this third try at the development of a Type 1 video coding standard progressed in the ISO approval process with the name Video Coding for Browsers (VCB), significant improvements were reported in the activity initiated by the second proposal submitted to the first CfP. At the June 2015 meeting the performance reported was equivalent to that of the AVC High Profile, hence much more than what had been requested 4 years before. At that meeting MPEG initiated the ISO approval process.

The jury is still out before MPEG succeeds in publishing a Type 1 Video Coding standard, but one conclusion can be drawn namely that, with a delay of about 10 years, it might be possible to achieve with a Type 1 standard the same performance achievable with a Type 2 standard.