H264/AVC profile and level

H264 specifies three major grades, each of which supports a specific set of encoding functions and a specific class of applications.

 

1. Baseline profile: The I-and p-slices support intra-and inter-frame encoding and context-based adaptive variable-length encoding (cavlc ). It is mainly used for real-time video communication, such as videophone, conference TV, and wireless communication.

2. Main profile: supports video interlace, B-frame encoding, and weighted prediction; supports context-based adaptive arithmetic coding (cabac ). It is mainly used for digital broadcast and television and digital video storage.

3. Extended profile: supports effective switching between code streams (SP and Si slices) and improves error code performance, but does not support interline videos and cabac.

 

 

Figure 6.3 shows the h264 grade and different features of each grade. It can be seen that the extension level includes all the functions of the basic level, but not the main level. Different parameters (such as sampling rate, image size, and encoding bit) are set for each level to obtain different levels of encoding and decoder performance.

 

 

References:

1. New Generation video compression coding standard;

2. h264 and MPEG-4 video compression.