Partial reply: FFmpeg's CC decoder is actually pretty decent for pop-on CC but produces non-compliant ASS that needs postprocessing.
ASS can cover and render the pop-ons quite well, but the fundamental limitation with representing EIA608 with ASS is that ASS does not allow arbitrary positioning AND justification at the same time, without making each line its own cue and carefully positioning the cues or applying some other complex workarounds. The only alternative I can think of within the ASS domain is to use heuristics to determine numpad positioning of the caption cue and declare justification tags without arbitrary positioning, but it needs work and will not be exact. This is a problem for say, I want to render a cue at position x,y but I want it also left justified at that position. I will share details and an example in my slides. I am personally not a fan of WebVTT but irrelevant to the advancements I'm hoping to make. I think baby steps have to come first. Have a good day, _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
