On Thu, Feb 27, 2020 at 12:35:03PM +0100, Anton Khirnov wrote: [...] > AFAIU one of the still-open questions for the subtitle redesign is what > does it mean to decode or encode a subtitle.
There are multiple markups available for text subtitles, and there are multiple ways of representing graphic rectangles for bitmap subtitles. So for text subtitles, decoding and encoding respectively means transforming them in a common markup to represent them all (currently ASS is our "raw" representation) and back into their markup specifications. We have a bunch of those already (subrip, microdvd, subviewer, ...). For bitmap subtitles, decoding and encoding respectively means transforming the bitstream into rectangle structures with RAW images inside and back into the codec-specific bitstream. > And one of the options is putting the AVPacket->"decoded subtitle" > (whatever that is) and "decoded subtitle"->AVPacket conversions into a > separate library. And then you can't have them in libavfilter, so you can't have a sane harmony with medias including subtitle streams. It's problematic with many basic use cases. One random example: if you're transcoding an audio/video and somehow altering the timings within lavfi, you have to give the subtitles. Having subtitles within libavfilter is not a fancy utopia to give ourselves a reason to write a bunch of random filters, it actually helps addressing real limitations in the current model. What you are suggesting is basically what we already have: the few subtitles specific API already present in lavc is what you would want out of it, but it won't solve the core issues. -- Clément B. _______________________________________________ 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".