> -----Original Message----- > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org> On Behalf Of Tom > Vaughan > Sent: Friday, February 7, 2025 7:36 PM > To: FFmpeg development discussions and patches <ffmpeg- > de...@ffmpeg.org> > Subject: Re: [FFmpeg-devel] Captions SCC > > Soft Works said... "the CC data needs to get into the video frames - > so that it exists as input to the video encoder. > For the same reason, it is also not possible to add CCs at the muxer > level. It always requires video encoding because the data needs to > get into the video stream itself, so there's no way to get data from > an SCC file into a video stream currently."
Hi Tom, > You're confusing subtitles with closed captions. No. > Subtitles are text that is composited into the video. No. > CEA-708 closed captions are > carried as metadata in SEI NAL units, muxed into the elementary video > stream. I wouldn't call this "muxing" but that's not worth a debate. (you might want to spend a thought on why it's called "elementary stream") I said "it is also not possible to add CCs at the muxer level". By that I mean "muxing" in ffmpeg terminology which is unambiguous. sw > > On 2/6/25, 11:48 PM, "ffmpeg-devel on behalf of Soft Works" <ffmpeg- > devel-boun...@ffmpeg.org <mailto:ffmpeg-devel-boun...@ffmpeg.org> on > behalf of softworkz-at-hotmail....@ffmpeg.org <mailto:softworkz-at- > hotmail....@ffmpeg.org>> wrote: > > > > -----Original Message----- > > From: ffmpeg-devel <ffmpeg-devel-boun...@ffmpeg.org <mailto:ffmpeg- > devel-boun...@ffmpeg.org>> On Behalf Of > > Devlist Archive > > Sent: Friday, February 7, 2025 6:13 AM > > To: FFmpeg development discussions and patches <ffmpeg- > > de...@ffmpeg.org <mailto:de...@ffmpeg.org>> > > Subject: Re: [FFmpeg-devel] Captions SCC > > > Hi Zack, > that message from "Jack" had confused me for a moment, but on re- > reading it appears to be an AI response. > The content is total nonsense. There is no "SCC" encoder in ffmpeg, > and if there was one, it wouldn't help much because the CC data needs > to get into the video frames - so that it exists as input to the > video encoder. > For the same reason, it is also not possible to add CCs at the muxer > level. It always requires video encoding because the data needs to > get into the video stream itself, so there's no way to get data from > an SCC file into a video stream currently. > > The only way in the ffmpeg architecture to get CC data encoded would > be at the filtering level. The Subtitle Filtering patchset that I > have submitted a while ago has a "splitcc" filter which has video as > input and a video plus a subtitle pin/pad at the output side. > What would be needed is a reverse pendant like a "mergecc" filter > with video and subtitles input - plus a CEA-608/708 encoder. > > softworkz > > _______________________________________________ > 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". _______________________________________________ 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".
