Video coding and decoding

A system for encoding video data with transparency features, comprising:

• one or more processors;
• and
• a memory comprising instructions stored thereon, which when executed by the one or more processors, causes the one or more processors to:
• identify a keyframe in a source video;
• determine differences between the keyframe and one or more subsequent frames in the source video;
• generate a diff image comprising blocks mapping the differences;
• encode alpha channel data representing per-pixel transparency for the keyframe and the diff images;
• store metadata comprising block coordinates indicating a position of the differences, source frame identifiers associated with each of the blocks, and alpha channel data;
• and
• compress the keyframe, the diff images, and the metadata into a compressed file for transmission and playback.

A non-transitory computer-readable storage medium comprising instructions stored thereon, which when executed by one or more processors, cause the one or more processors to perform operations comprising:

• identifying a keyframe in a source video;
• determining differences between the keyframe and one or more subsequent frames in the source video;
• generating a diff image comprising blocks mapping the differences;
• encoding alpha channel data representing per-pixel transparency for the keyframe and the diff images;
• storing metadata comprising block coordinates indicating a position of the differences, source frame identifiers associated with each of the blocks, and alpha channel data;
• and
• compressing the keyframe, the diff images, and the metadata into a compressed file for transmission and playback.