Advanced Video Coding
[5][6] The intent of the H.264/AVC project was to create a standard capable of providing good video quality at substantially lower bit rates than previous standards (i.e., half or less the bit rate of MPEG-2, H.263, or MPEG-4 Part 2), without increasing the complexity of design so much that it would be impractical or excessively expensive to implement.
An additional goal was to provide enough flexibility to allow the standard to be applied to a wide variety of applications on a wide variety of networks and systems, including low and high bit rates, low and high resolution video, broadcast, DVD storage, RTP/IP packet networks, and ITU-T multimedia telephony systems.
H.264 is typically used for lossy compression, although it is also possible to create truly lossless-coded regions within lossy-coded pictures or to support rare use cases for which the entire encoding is lossless.
The final drafting work on the first version of the standard was completed in May 2003, and various extensions of its capabilities have been added in subsequent editions.
It is also widely used by streaming Internet sources, such as videos from Netflix, Hulu, Amazon Prime Video, Vimeo, YouTube, and the iTunes Store, Web software such as the Adobe Flash Player and Microsoft Silverlight, and also various HDTV broadcasts over terrestrial (ATSC, ISDB-T, DVB-T or DVB-T2), cable (DVB-C), and satellite (DVB-S and DVB-S2) systems.
MPEG LA has allowed the free use of H.264 technologies for streaming Internet video that is free to end users, and Cisco paid royalties to MPEG LA on behalf of the users of binaries for its open source H.264 encoder openH264.
The JVT was (is) chaired by Gary Sullivan, Thomas Wiegand, and Ajay Luthra (Motorola, U.S.: later Arris, U.S.).
The JVT management team was extended by Jens-Rainer Ohm (RWTH Aachen University, Germany).
SEI messages do not affect the core decoding process, but can indicate how the video is recommended to be post-processed or displayed.
In the first project to extend the original standard, the JVT then developed what was called the Fidelity Range Extensions (FRExt).
Several other features were also included in the FRExt project, such as adding an 8×8 integer discrete cosine transform (integer DCT) with adaptive switching between the 4×4 and 8×8 transforms, encoder-specified perceptual-based quantization weighting matrices, efficient inter-picture lossless coding, and support of additional color spaces.
Specified in Annex H of H.264/AVC, MVC enables the construction of bitstreams that represent more than one view of a video scene.
[33] Sony claims that 9 Mbit/s AVC recording mode is equivalent to the image quality of the HDV format, which uses approximately 18–25 Mbit/s.
Many common DSLRs use H.264 video wrapped in QuickTime MOV containers as the native recording format.
AVCHD is a high-definition recording format designed by Sony and Panasonic that uses H.264 (conforming to H.264 while adding additional application-specific features and constraints).
[42][43] H.264/AVC/MPEG-4 Part 10 contains a number of new features that allow it to compress video much more efficiently than older standards and to provide more flexibility for application to a wide variety of network environments.
The standard defines several sets of capabilities, which are referred to as profiles, targeting specific classes of applications.
The maximum capacity of the DPB, in units of frames (or pairs of fields), as shown in parentheses in the right column of the table above, can be computed as follows: Where MaxDpbMbs is a constant value provided in the table below as a function of level number, and PicWidthInMbs and FrameHeightInMbs are the picture width and frame height for the coded video data, expressed in units of macroblocks (rounded up to integer values and accounting for cropping and macroblock pairing when applicable).
Thus, a decoder needs to actually have sufficient memory to handle (at least) one frame more than the maximum capacity of the DPB as calculated above.
At the Gartner Symposium/ITXpo in November 2010, Microsoft CEO Steve Ballmer answered the question "HTML 5 or Silverlight?"
However, any software projects that use Cisco's source code instead of its binaries would be legally responsible for paying all royalties to MPEG LA.
Target CPU architectures include x86 and ARM, and target operating systems include Linux, Windows XP and later, Mac OS X, and Android; iOS was notably absent from this list, because it doesn't allow applications to fetch and install binary modules from the Internet.
quad-core general-purpose x86 CPUs have sufficient computation power to perform real-time SD and HD encoding.
CPU based solutions are known to be much more flexible, particularly when encoding must be done concurrently in multiple formats, multiple bit rates and resolutions (multi-screen video), and possibly with additional features on container format support, advanced integrated advertising features, etc.
ASIC encoders with H.264 encoder functionality are available from many different semiconductor companies, but the core design used in the ASIC is typically licensed from one of a few companies such as Chips&Media, Allegro DVT, On2 (formerly Hantro, acquired by Google), Imagination Technologies, NGCodec.
[71] This permits flexibility with respect to codecs (which are implemented as highly optimized DSP code) while being more efficient than software on a generic CPU.
[75] On August 26, 2010, MPEG LA announced that royalties won't be charged for H.264 encoded Internet video that is free to end users.
[78] Since the first version of the standard was completed in May 2003 (21 years ago) and the most commonly used profile (the High profile) was completed in June 2004[citation needed] (20 years ago), some of the relevant patents are expired by now, [75] while others are still in force in jurisdictions around the world and one of the US patents in the MPEG LA H.264 pool (granted in 2016, priority from 2001) lasts at least until November 2030.
[80] In 2007, the District Court found that the patents were unenforceable because Qualcomm had failed to disclose them to the JVT prior to the release of the H.264 standard in May 2003.
[80] In October 2023 Nokia sued HP and Amazon for H.264/H.265 patent infringement in USA, UK and other locations.
