H.264, MPEG-4 Part 10 or AVC (Advanced Video Coding) is a standard for encoding digital video that is distinguished by a high compression rate. It was written by the Video Coding Experts Group (VCEG) from ITU with Moving Picture Experts Group (MPEG) of ISO / IEC, the collective product of the partnership known as the Joint Video Team (JVT).
ITU-T H.264 and ISO / IEC MPEG-4 Part 10 (formerly ISO / IEC 14496-10) are technically identical.
Introduction
H.264 is the name of the corresponding line of video standards H.26x ITU-T and MPEG AVC is related to the colaborararii who completed a standard, and that after the initial efforts of ITU-T H.264 standard called it. Usually, the standard is called H.264 / AVC (or AVC / H.264 or H.264 / MPEG-4 AVC or MPEG-4 / H.264 AVC) to emphasize the common heritage.
H.264 name that makes reference to ITU-T history, is less known, but it still in use. Occasionally, he is also known as "the JVT codec", evoking JVT organzation that has developed. This partnership and the many names are not a new thing, for as video codec known as MPEG-2 also appeared in the partnership between MPEG and ITU-T and the video codec MPEG-2 is known in the ITU-T as H.262).
The project goal H.264 / AVC was to create a standard that would provide better image quality in terms of rates significantly lower coding information (eg half or less) than what previous standards which necessitated (eg compared to MPEG-2, H.263, or MPEG-4 Part 2), and this without too much complexity implementations increase that would have resulted in higher prices for practical implementations. An end adjacent was to provide a flexible mechanism to allow the standard to be used for a wide range of applications (for drives with transfer rates of both low and high for resolution video high or low) and to work well with a large range of networks and systems (eg transmissions broadcast, DVD storage, networking switching RTP / IP, and ITU-T multimedia telephony systems).
JVT recently completed development work towards the original standard extensions known as Fidelity Range Extensions (FRExt). These extensions are designed to support video encoding at a higher resolution by increasing the accuracy of evidence (including encode 10-bit and the 12-bit) and color information at a higher resolution (including structures of samples known as YUV 4 : 2: 2 and YUV 4: 4: 4).
Several new features have also been introduced in the draft Fidelity Range Extensions (such as adaptive commutation between transforms between 4x4 and 8x8 across, quantization weight matrix for specific perceptual encoding, lossless encoding efficiency between images, support for additional color spaces, and color transform residual). Design work for Fidelity Range Extensions was completed in July 2004 and the document was completed in September 2004.
Profiles
The standard includes the following seven sets of capabilities, which are called profiles and have different applications:
- Baseline Profile (BP): mainly for low-cost applications with limited computational resources, video conferencing and mobile applications.
- Main Profile (MP): The original goal was a mainstream profile for transmission and storage applications, the importance of this low profile when the profile High profile was developed for that type of application.
- Extended Profile (XP): In order to be streaming video profile, this profile has relatively high compression and protected against data loss.
- High Profile (HiP): The main profile applications transmission and disk storage, particularly for applications in high definition television (ie profile is used for storing movies on HD DVD discs and Blu-ray Discs).
- High 10 Profile (Hi10P): This profile capabilities beyond ordinary consumer products, based on the added support for High Profile to 10 bits per sample of decoded picture precision.
- High 4: 2: 2 Profile (Hi422P): Designed for professional applications, use interlaced video.
- High 4: 4: 4 Predictive Profile (Hi444PP): This profile is based on all the High 4: 2: 2 Profile supports a chromatic sampling 4: 4: 4 up to 14 bits per sample, plus coding regional and lossless coding of each picture as three separate color planes.
In addition, the standard profiles now contains four additional all-Intra profiles, which are defined as simple subsets of corresponding profiles. They are used for professional applications:
- High 10 Intra Profile
- High 4:2:2 Intra Profile
- High 4:4:4 Intra Profile
- CAVLC 4:4:4 Intra Profile
