A quick reminder: CODEC stands for COmpression and DECompression or also COder and DECoder. Each Video CODEC defines several profiles and levels. These profiles and levels are used to address various applications ranging from low quality to high definition. Firstly, a video CODEC profile defines the characteristics of the video stream that are supported such as color space, the aspect ratio, the number of bits per pixel, and the interlacing support. To be able to decode the video, the decoder must match the encoder profile support. Secondly, a video CODEC level specifies constraints within a profile such as maximum resolution or maximum bitrate. For each CODEC profile, several levels are associated.