сб, 30 сент. 2023 г., 19:31 Stéphane Archer <archersteph...@gmail.com>:
> On Sat, Sep 30, 2023 at 11:00 AM David Bernat <david.ber...@gmail.com> > wrote: > > > Been very seriously considering design scope. Dropbox is a no-go. Want to > > connect offline to describe your use case? > > > > > > On Sat, Sep 30, 2023 at 10:10 AM Stéphane Archer < > archersteph...@gmail.com > > > > > wrote: > > > > > On Sat, Sep 30, 2023 at 10:00 AM Andrew Randrianasulu < > > > randrianas...@gmail.com> wrote: > > > > > > > сб, 30 сент. 2023 г., 16:58 Stéphane Archer < > archersteph...@gmail.com > > >: > > > > > > > > > Is there an equivalent of Drobox Lepton but for h.264 videos? > > > > > Lepton is a lossless compression algorithm to compress jpeg at > around > > > 20% > > > > > there initial file size without any data loss. This is ideal to > > > > > achieve jpeg. > > > > > What about h.264 videos? > > > > > > > > > > > > > > > > > well, h264 videos already heavy and usually lossy compressed, any > > further > > > > compression will be not lossless > > > > > > > > > > lepton works on jpeg that are lossy, yet they manage to have a smaller > > file > > > size adding a lossless compression on top of it. > > > I'm not sure why it won't be possible to do the same on a h.264 file > and > > > get a smaller file size. I know h.265 and av1 have lossless video > > > compression. And I recently heard about FFV1. > > > > > > > Dear David, I don't understand what you mean by "design scope". > > I would like to try a different analogy > > If the data was text and I wanted lossy compression then I would replace > all the vowels with an "a" and then compress the resulting data with gzip. > > now if I switch gzip by using lzma instead, I would end up with a file > smaller or the same size as the gzip version. Why does lossless h.265 or > lossless av1 give me a larger file size than the original h.264? Why is > this different for video? > As far as I understand all those h26x series of codes use https://en.m.wikipedia.org/wiki/Motion_estimation so only small difference between non-keyframes encoded, making file smaller (unless you try to compress say analog tv noise ...) DCT part is usually lossy by dropping some numbers ... so, if I understand correctly you can repack jpeg slightly differently, or recompress it completely into something like jpeg-xl, but video usually get a lot more info already removed, due to way only parts of image usually changes from frame to frame. > I hope my text compression analogy was clear. > > -- > Best Regards, > > Stephane Archer > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
