Changes since v1: - Correctly implement alpha mode tagging for JPEG XL - Set correct alpha mode for OpenEXR (which is always premultiplied) - Ensure -alpha_mode specified on the command line correctly propagates - Print out a warning when overriding the alpha mode explicitly
Includes an unrelated fix for -chroma_sample_location also being ignored, since the fix for that was adjacent to the fix for the alpha mode field. Submitting this for re-evaluation. I decided in the end not to include full negotiation for the alpha mode, primarily because there is no filter currently existing that only handles one or the other. The only thing that represents a source of incompatibility is the codec itself, but that already errors out with a clearly defined error message when requesting an incompatible alpha mode - and I think the explicit fix (i.e. user inserts the corresponding (un)premultiply filter) is bettter than an implicit conversion, due to the potential for loss of information as well as breaking workflows that rely on additive blending (which only works for premultiplied alpha and thus cannot be converted - even explicitly). If the error message is really bothersome, we could add a small routine inside libavcodec for applying the unpremultiplication directly, but this would IMO be a layering violation. (Not to mention duplicating code) _______________________________________________ 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".
