Systems and methods for signaling of downsampling filters for chroma from luma intra prediction mode

A computing system, comprising:

• control circuitry;
• memory;
• and
• one or more sets of instructions stored in the memory and configured for execution by the control circuitry, the one or more sets of instructions comprising instructions for:
• receiving a video stream having a sequence of frames, the sequence of frames including one or more key frames, and each key frame having a respective downsampling filter type;
• in accordance with a determination that a current frame corresponds to a first key frame of the one or more key frames:
• retrieving, from the video stream, a syntax element associated with a first downsampling filter type associated with the first key frame;
• downsampling a luma block of the current frame and a predefined set of frames immediately after the current frame using the first downsampling filter type to obtain downsampled frames;
• and
• predicting a chroma block of the current frame based on the downsampled frames.

A non-transitory computer-readable storage medium storing one or more sets of instructions configured for execution by a computing device having control circuitry and memory, the one or more sets of instructions comprising instructions for:

• receiving a video stream having a sequence of frames, the sequence of frames including one or more key frames, and each key frame having a respective downsampling filter type;
• in accordance with a determination that a current frame corresponds to a first key frame of the one or more key frames:
• retrieving, from the video stream, a syntax element associated with a first downsampling filter type associated with the first key frame;
• downsampling a luma block of the current frame and a predefined set of frames immediately after the current frame using the first downsampling filter type to obtain downsampled frames;
• and
• predicting a chroma block of the current frame based on the downsampled frames.