A method and apparatus comprising computer code configured to cause a processor or processors to obtain video data including at least one coded picture; reconstruct a coded picture associated in the video data with a film grain characteristics SEI message, a first sample, a second sample, a third alpha map sample, and a fourth alpha map sample, wherein after reconstruction the first sample and the third alpha map sample, and the second sample and fourth sample are spatially co-located; apply film grain synthesis to the first sample based on a first value of the third sample; and determine to not apply film grain syntheses to the second sample based on a second value of the fourth sample, wherein the first value and second value are different from each other.