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AVC Profile & Level

AVC Profile

The standard defines several sets of capabilities, which are referred to as profiles, targeting specific classes of applications. These are declared using a profile code (profile_idc) and sometimes a set of additional constraints applied in the encoder. The profile code and indicated constraints allow a decoder to recognize the requirements for decoding that specific bitstream. (And in many system environments, only one or two profiles are allowed to be used, so decoders in those environments do not need to be concerned with recognizing the less commonly used profiles.) By far the most commonly used profile is the High Profile.

针对特定类别的应用程序,标准定义了几组功能,称为配置文件(profile)。这些功能是用一个配置文件代码(profile_idc)来声明的,有时还在编码器中应用一组额外的约束。配置文件代码和指定的约束条件允许解码器识别解码该特定比特流的要求。在许多系统环境中,只允许使用一个或两个配置文件,所以这些环境中的解码器不需要关注识别不太常用的配置文件)。到目前为止,最常用的配置文件是High Profile。

Profiles for non-scalable 2D video applications include the following:

用于非可扩展的二维视频应用的配置文件包括以下内容。

Constrained Baseline Profile (CBP, 66 with constraint set 1)

Primarily for low-cost applications, this profile is most typically used in videoconferencing and mobile applications. It corresponds to the subset of features that are in common between the Baseline, Main, and High Profiles.

主要用于低能耗的应用,这个配置文件最典型的应用场景是视频会议和移动应用。它对应于Baseline、Main和High配置文件之间的共同特征子集。

Baseline Profile (BP, 66)

Primarily for low-cost applications that require additional data loss robustness, this profile is used in some videoconferencing and mobile applications. This profile includes all features that are supported in the Constrained Baseline Profile, plus three additional features that can be used for loss robustness (or for other purposes such as low-delay multi-point video stream compositing). The importance of this profile has faded somewhat since the definition of the Constrained Baseline Profile in 2009. All Constrained Baseline Profile bitstreams are also considered to be Baseline Profile bitstreams, as these two profiles share the same profile identifier code value.

主要用于需要额外数据损失稳健性的低能耗应用,该配置文件用于一些视频会议和移动应用。该配置文件包括Constrained Baseline Profile中支持的所有功能,加上三个额外的功能,可用于损失稳健性(或用于其他目的,如低延迟多点视频流合成)。自2009年定义约束基线配置文件以来,该配置文件的重要性已有所淡化。所有受限基线配置文件的比特流也被认为是基线配置文件的比特流,因为这两个配置文件共享相同的配置文件标识码值。

Extended Profile (XP, 88)

Intended as the streaming video profile, this profile has relatively high compression capability and some extra tricks for robustness to data losses and server stream switching.

作为流媒体视频配置文件,该配置文件具有相对较高的压缩能力和一些额外的技巧,以增强对数据损失和服务器流切换的稳定性。

Main Profile (MP, 77)

This profile is used for standard-definition digital TV broadcasts that use the MPEG-4 format as defined in the DVB standard.[49] It is not, however, used for high-definition television broadcasts, as the importance of this profile faded when the High Profile was developed in 2004 for that application.

这个配置文件用于使用DVB标准中定义的MPEG-4格式的标清数字电视广播。然而,它不用于高清电视广播,因为当2004年为该应用开发出High Profile时,这个配置文件的重要性就消失了。

High Profile (HiP, 100)

The primary profile for broadcast and disc storage applications, particularly for high-definition television applications (for example, this is the profile adopted by the Blu-ray Disc storage format and the DVB HDTV broadcast service).

广播和光盘存储应用的主要配置文件,特别是高清电视应用(例如,这是蓝光光盘存储格式和DVB高清广播服务采用的配置文件)。

Progressive High Profile (PHiP, 100 with constraint set 4)

Similar to the High profile, but without support of field coding features.

类似于High profile,但不支持现场编码功能。

Constrained High Profile (100 with constraint set 4 and 5)

Similar to the Progressive High profile, but without support of B (bi-predictive) slices.

类似于Progressive High profile,但不支持B(双预测)切片。

High 10 Profile (Hi10P, 110)

Going beyond typical mainstream consumer product capabilities, this profile builds on top of the High Profile, adding support for up to 10 bits per sample of decoded picture precision.

超越了典型的主流消费产品的能力,这个配置文件建立在高配置文件的基础上,增加了对每个样本高达10比特的解码图像精度的支持。

High 4:2:2 Profile (Hi422P, 122)

Primarily targeting professional applications that use interlaced video, this profile builds on top of the High 10 Profile, adding support for the 4:2:2 chroma sampling format while using up to 10 bits per sample of decoded picture precision.

主要针对使用隔行扫描视频的专业应用,该配置文件建立在High 10 Profile的基础上,增加了对4:2:2色度采样格式的支持,同时使用高达10比特/采样的解码图像精度。

High 4:4:4 Predictive Profile (Hi444PP, 244)

This profile builds on top of the High 4:2:2 Profile, supporting up to 4:4:4 chroma sampling, up to 14 bits per sample, and additionally supporting efficient lossless region coding and the coding of each picture as three separate color planes.

这个配置文件建立在High 4:2:2 Profile的基础上,支持高达4:4:4的色度采样,每个采样高达14比特,另外还支持高效的无损区域编码和每个图片作为三个独立的颜色平面的编码。

For camcorders, editing, and professional applications, the standard contains four additional Intra-frame-only profiles, which are defined as simple subsets of other corresponding profiles. These are mostly for professional (e.g., camera and editing system) applications:

对于摄像机、编辑和专业应用,该标准包含四个额外的全I帧的配置文件,它们被定义为其他相应配置文件的简单子集。这些主要是针对专业(如摄像机和编辑系统)应用:

High 10 Intra Profile (110 with constraint set 3)

The High 10 Profile constrained to all-Intra use.

被约束为全I帧的High 10 Profile。

High 4:2:2 Intra Profile (122 with constraint set 3)

The High 4:2:2 Profile constrained to all-Intra use.

被约束为全I帧的High 4:2:2 Profile。

High 4:4:4 Intra Profile (244 with constraint set 3)

The High 4:4:4 Profile constrained to all-Intra use.

被约束为全I帧的High 4:4:4 Profile。

CAVLC 4:4:4 Intra Profile (44)

The High 4:4:4 Profile constrained to all-Intra use and to CAVLC entropy coding (i.e., not supporting CABAC).

High 4:4:4 Profile限制在所有内部使用和CAVLC熵编码(即,不支持CABAC)。

As a result of the Scalable Video Coding (SVC) extension, the standard contains five additional scalable profiles, which are defined as a combination of a H.264/AVC profile for the base layer (identified by the second word in the scalable profile name) and tools that achieve the scalable extension:

由于可扩展视频编码(SVC)的扩展,该标准包含五个额外的可扩展配置文件,它们被定义为基础层的H.264/AVC配置文件(由可扩展配置文件名称中的第二个字标识)和实现可扩展的工具的组合:

Scalable Baseline Profile (83)

Primarily targeting video conferencing, mobile, and surveillance applications, this profile builds on top of the Constrained Baseline profile to which the base layer (a subset of the bitstream) must conform. For the scalability tools, a subset of the available tools is enabled.

主要针对视频会议、移动和监控应用,该配置文件建立在Constrained Baseline profile之上,基础层(比特流的一个子集)必须符合该配置文件。对于可扩展性工具,启用了可用工具的一个子集。

Scalable Constrained Baseline Profile (83 with constraint set 5)

A subset of the Scalable Baseline Profile intended primarily for real-time communication applications.

Scalable Baseline Profile的一个子集,主要用于实时通信应用。

Scalable High Profile (86)

Primarily targeting broadcast and streaming applications, this profile builds on top of the H.264/AVC High Profile to which the base layer must conform.

主要针对广播和流媒体应用,该配置文件建立在H.264/AVC High Profile之上,基础层必须符合该配置文件。

Scalable Constrained High Profile (86 with constraint set 5)

A subset of the Scalable High Profile intended primarily for real-time communication applications.

Scalable High Profile的一个子集,主要用于实时通信应用。

Scalable High Intra Profile (86 with constraint set 3)

Primarily targeting production applications, this profile is the Scalable High Profile constrained to all-Intra use.

主要针对生产应用,该配置文件是Scalable High Profile,限制为全I帧。

As a result of the Multiview Video Coding (MVC) extension, the standard contains two multiview profiles:

由于多视角视频编码(MVC)的扩展,该标准包含两个多视角配置文件:

Stereo High Profile (128)

This profile targets two-view stereoscopic 3D video and combines the tools of the High profile with the inter-view prediction capabilities of the MVC extension.

该配置文件针对双视角立体3D视频,并结合了High profile的工具和MVC扩展的视角间预测能力。

Multiview High Profile (118)

This profile supports two or more views using both inter-picture (temporal) and MVC inter-view prediction, but does not support field pictures and macroblock-adaptive frame-field coding.

该配置文件支持两个或多个视图,使用帧间(时间)和MVC帧间预测,但不支持场图和宏块自适应帧场编码。

The Multi-resolution Frame-Compatible (MFC) extension added two more profiles:

多分辨率帧兼容(MFC)扩展又增加了两个配置文件:

MFC High Profile (134)

A profile for stereoscopic coding with two-layer resolution enhancement.

用于具有两层分辨率增强的立体编码的配置文件。

MFC Depth High Profile (135)

The 3D-AVC extension added two more profiles:

3D-AVC扩展又增加了两个配置文件:

Multiview Depth High Profile (138)

This profile supports joint coding of depth map and video texture information for improved compression of 3D video content.

该配置文件支持深度图和视频纹理信息的联合编码,以改善3D视频内容的压缩。

Enhanced Multiview Depth High Profile (139)

An enhanced profile for combined multiview coding with depth information.

一个增强的配置文件,用于结合深度信息的多视图编码。

特定配置支持的配置

软件编码器实现

AVC Level

As the term is used in the standard, a "level" is a specified set of constraints that indicate a degree of required decoder performance for a profile. For example, a level of support within a profile specifies the maximum picture resolution, frame rate, and bit rate that a decoder may use. A decoder that conforms to a given level must be able to decode all bitstreams encoded for that level and all lower levels.

正如标准中所使用的术语,level是一组特定的约束条件,表明一个配置文件所要求的解码器性能的程度。例如,一个配置文件中的支持级别规定了解码器可以使用的最大图片分辨率、帧率和比特率。符合某一等级的解码器必须能够解码为该等级和所有更低等级编码的所有比特流。

各Level的最大属性值

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