Niklas Haas (HE12025-07-29): > I think this would involve more invasive changes (i.e. adding negotiation to > the avfilter code for this and ideally other properties) that you and I both > agreed is out of scope of this series.
No it does not. You just need to add a flag “this filter supports premultiplied alpha” and have the framework throw an error if the flag is not set. We can later use the flag for negotiation or replace it with something else, as it is purely internal API. > If it makes you feel better, I could add an error message to the stacking > filters specifically, for now? Do you really think the stacking filters are the only ones where the problem can happen? > You argue that premultiplied frames were an "anecdotal experimental feature" > only up until this series, but this is flat out untrue; because this series > does not change how files are decoded. In every scenario that you worry about > now getting the wrong result, you would have gotten the wrong result even > before my changes. That is the point: you are making a change to make it work. You are officializing support, do it properly. The other time that would have been the right time would have been when Paul added the premultiply filter. But unless you have a TARDIS, that is not an option. You want the glory? Do the work. As I pointed in the first paragraph, it is quite easy. It certainly would have taken you less time than arguing with me. I do not understand why you want to use past sloppiness to justify present sloppiness when you could treat it as low-hanging fruits. By the way, there is another flaw that I just noticed in this series: it does not have any transverse user documentation. Sure you added the documentation for the options, but it also need a few paragraphs to explain to the user what premultiplied alpha is and what to do with it. -- Nicolas George _______________________________________________ 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".
