ISO/IEC 14496-10:2009, Coding of audio-visual objects – Part 10: Advanced Video Coding [AVC].

ITU-T Rec. H.264, Advanced video coding for generic audiovisual services.

SMPTE 421M, VC-1 Compressed

Video Bitstream Format and

Decoding Process.

SMPTE RP 227, VC-1 Bitstream

Transport Encodings.

SMPTE RP 228, VC-1 Decoder and

Bitstream Conformance.

H.264

An effort to extend MPEG-2 coding was undertaken by the Joint Video Team (JVT). During development, this effort worked toward advanced video coding (AVC). The resulting standard is promulgated jointly by by ITU-T (who call it H.264) and by ISO/IEC (who call it MPEG-4 Part 10, despite its having little to do with the rest of MPEG-4). H.264 encoding is roughly 1.5 or 2 times as efficient as MPEG-2 – that is, H.264 typically allows encoding at somewhat more than half the bit rate of MPEG-2 for similar picture quality levels. The Blu-ray standard mandates inclusion of H.264 decoding in consumer players. Details are found in H.264 video compression, on page 537.

AVC-Intra

An I-frame-only specialization of H.264 has been introduced for professional video acquisition and production, called AVC-Intra. Ten-bit vIdeo in 720p, 1080i, or 1080p24 format is compressed to data rates of 50 Mb/s or 100 Mb/s.

In AVC-Intra 50, 1920× 1080 images are subsampled to 1440× 1080, 4:2:0 prior to compression; H.264 Hi10P Intra profile at level 4 is used. 1280× 720 images are subsampled to 960× 720; 4:2:0; H.264 level 3.2 is used.

AVC-Intra 100 codes 1280× 720 and 1920× 1080 natively, uses 4:2:2 chroma subsampling, and codes to H.264 Hi422P Intra profile at level 4.1.

WM9, WM10, VC-1 codecs

Microsoft developed a series of video codecs culminating in Windows Media Video versions 9 and 10 (WMV9 and WMV10). These codecs are conceptually similar to – but differ in detail from – H.264. Microsoft submitted the WMV9 codec to SMPTE, where with slight changes it was standardized as VC-1 (corresponding to Windows Media Video 9 – WMV9 or WM9 – Studio profile).

Microsoft developed a proprietary implementation of an encoder and decoder for WM9 (and its successor, Windows Media Video 10). The VC-1 specification was used to produce a “clean-room” implementation of

www.webmproject.org

Dirac seems to be the BBC’s preferred designation for the longGoP wavelet codec intended for use in video distribution. Here we use the qualifier basic to distinguish it from Dirac PRO (see page 151).

AVCHD

A specialization of H.264 for consumer use is called AVCHD. AVCHD compresses 720p, 1080i, and 1080p24 video using long-GoP H.264 coding, to bit rates between about 6 Mb/s and 18 Mb/s. Dolby

Digital audio coding is used. AVCHD has been adapted to semi-professional use for recording on 12 cm DVD-R media, SDHC flash memory cards, or hard disk drives.

Compression for IP transport to consumers

The proliferation of personal computers, notebook computers, handheld devices, and tablets, most having WiFi connection and all able to execute software-based video decompression, has led to software-based codec implementations having performance beyond MPEG-2.

Apple has invested in, and has widely deployed, H.264 codecs. H.264 was outlined earlier in this chapter, and is detailed in Chapter 48 on page 537.

Google prefers WebM, to be outlined below.

There is a handful of proprietary codecs in this application domain, including RealPlayer and Adobe Flash Video. (Recent Flash players include H.264 decoding.)

VP8 (“WebM”) codec

In 2010, Google acquired a company called On2 that had, over a decade or more, developed a series of proprietary software-based codecs for video distribution. Google released the VP8 codec as open-source, and introduced the WebM system for web (IP-based) distribution of video to consumers. WebM comprises video encoded by the VP8 codec and audio encoded by the Vorbis codec, both wrapped in the Matroska file wrapper. Google’s motivation is to avoid paying royalties – and to avoid having its customers pay royalties – on MPEG-2 or H.264 intellectual property (patent) licences.

Dirac (basic)

Basic Dirac is a long-GoP motion-compensated interframe wavelet codec developmed by the BBC and its partners. It has been widely deployed by the BBC for SD distribution between 2–4 Mb/s and for HD distribution between 15–18 Mb/s.