"Go" H264 video encoding level description profile levels Encoder

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The first thing to clarify is that the so-called AVC is actually the H. T standard, which is developed by the Joint Video group (Jvt,joint video team), which is made up of ITU/IEC, and the ITU-T gives the standard a name of H. S (formerly known as h.26l) and iso/ The IEC calls it the MPEG-4 Advanced video codec, which is positioned to cover the entire range of video applications, including low-bitrate wireless applications, standard definition and high-definition TV broadcast applications, video streaming applications on the internet, Transfer high-definition DVD videos and high-quality video applications for digital cameras, and more.

AVC specifications are divided into three,
from low to High, respectively: Baseline, Main, Gao.
Baseline (lowest profile) level supports i/p frames, only supports no interleaving (Progressive) and CAVLC, generally for low-order or need additional fault-tolerant applications, such as video calls, mobile video, etc.;
The main profile level provides i/p/b frames, support for no interleaving (Progressive) and interleaving (interlaced), as well as support for CAVLC and CABAC for mainstream consumer electronic product specifications such as low decoding (relatively) MP4, Portable video player, PSP and ipod etc;
The high (higher profile, also called FRExt) level adds 8x8 internal prediction, custom quantization, lossless video encoding, and more YUV formats (such as 4:4:4) on Main, for broadcast and video disc storage (Blu-ray film), HDTV applications.
AVC specifications are primarily for compatibility, and different specifications can be applied at the same level on the platform. As for [email protected] x.x, [email protected] x.x, [email protected] x.x form is at different levels of the stream level, the larger the value of the greater the size of the stream, more resource-intensive. So in terms of bitstream [email protected]<[email protected]<[email protected].

There are four levels of image quality, namely BP, EP, MP, HP:

1, Bp-baseline profile: Basic picture quality. Support i/p frame, only support no interleaving (Progressive) and CAVLC;

2, ep-extended Profile: Advanced quality. Support I/p/b/sp/si frame, only support no interleaving (Progressive) and CAVLC;

3, Mp-main profile: The mainstream picture quality. Provides i/p/b frames, supports no interleaving (Progressive) and interleaving (interlaced), and supports CAVLC and CABAC support;

4. Hp-high Profile: Advanced image quality. Based on the main profile, 8x8 internal prediction, custom quantization, lossless video coding and more YUV formats are added.

The difference between H + H and MP is to explain the technology development of H. JVT completed the basic part of the standard work in 2003, including Baseline profile, Extended profile, and main profile, respectively, with different coding tools. The JVT then completed the development of the Extended Section (Amendment) of the H. FRExt (i.e., Fidelity Range Extensions), including high profile (HP), the high profile (hi10p), the high 4:2:2 profile (hi422p), High 4:4:4 profile (hi444p) 4 profiles.

H. Baseline profiles, Extended profile and main profile are all video sequences for 8-bit sample data, 4:2:0 format, FRExt extend it to 8~12 bit sample data, video format can be 4:2:0, 4:2:2 , 4:4:4, set up 4 profiles for high profile (HP), high profile (hi10p), High 4:2:2 profiles (hi422p), High 4:4:4 profiles (hi444p), The 4 profiles are based on the main profile.

In the same configuration, high profile (HP) can save up to 10% of the code flow compared to main profiles (MP), saving 60% of the code traffic compared to the MPEG-2 MP, with better coding performance. According to the different application fields, Baseline profile is applied in the field of real-time communication, the Main profile is applied in the field of streaming media, and high profile is used in broadcasting and storage field more.

H. Baseline profile corresponds to MPEG-4 SP. H. P. MPEG-4 ASP. Extended profile corresponds to MPEG-4 ARTS or FGS H. Baseline Profile corresponds to MPEG-4 Studio.

Three drawings of profile, level and encoder

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"Go" H264 video encoding level description profile levels Encoder