Clément Bœsch

When I say libav*, I and most people mean libavformat, libavcodec, libswscale, etc.; the C libraries that form the basis of the command line tool and are widely used elsewhere. libav (no wildcard) is a fork of FFmpeg that is broadly focused on reducing bloat and cleaning up the API. As such, libav tends to add features more slowly, while FFmpeg generally follows all of libav’s new features and bug fixes as well as its own [1]. Debian was on libav for a while but went back to FFmpeg in 2015 [2]. [1] http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html [2] http://news.softpedia.com/news/Debian-Moves-to-FFmpeg-and-Drops-Libav-…

http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html There's probably some great popcorn in mailing lists. Edit: libav have a big "personal conflict resolution" section here which is another hint: http://libav.org/about/

About time. I'm usually all for forking and variety, but libav truly was an example of those gratuitous and destructive forks that offered no real benefit. Though, ultimately, it was the Debian package maintainers' decision to spread propaganda about ffmpeg being deprecated that was the worst. As a practical example, I was gridlocked when I tried to compile LightSpark from Git, due to libswresample not being present, nor practically obtainable. Editing it out from cmake, predictably, lead to breakage. Here's a classic article detailing the situation: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html And from the mpv developers: https://github.com/mpv-player/mpv/wiki/FFmpeg-versus-Libav

It sounds like you've got something specific in mind when you say, "modeling". The term modeling is used in a lot of different situations to mean different things. For example, it could mean to make a 3d model in Blender, it could mean to pose for someone to paint you or to take a photo, with databases it's used to mean modeling the data, with statistics it's used to mean finding a way to simply represent and reason about the data (create a model of it). The things you've listed out make me guess you want to write 2d or 3d image rendering software. Is that right? If that's the case, there's no substitute for trying to recreate certain algorithms or curves using a language or tool that you're comfortable with. It'll help you build an intuition about how the mathematical object behaves and what problems it solves (and doesn't). All of these approaches were created to solve problems, understanding the theory of it doesn't quite get you there. If you don't have a good place to try out functions, I recommend https://thebookofshaders.com/05/ , https://www.desmos.com/calculator , or https://www.geogebra.org/calculator . A good place to start is linear interpolation (lerp). It seems dead simple, but it's used extensively to blend two things together (say positions or colors) and the other things you listed are mostly fancier things built on top of linear interpolation. https://en.wikipedia.org/wiki/Linear_interpolation For bezier curves and surfaces here are some links I've…

> libav [...] promoted as a concerted effort to create a better API True, but that was biased and unfair. Some developers leveraged their Debian influence to get Debian to switch from ffmpeg to libav, but the technical merits were debatable. In the end, they came back to ffmpeg. This is mostly a political issue. Software-wise AFAIK ffmpeg has been integrating many changes from libav but the opposite is not true, making IMHO ffmpeg the right choice. Good article (2012) with in-depth history: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html More recent (2015) short take on the matter, seems pretty biased though: https://github.com/mpv-player/mpv/wiki/FFmpeg-versus-Libav Wikipedia entry: https://en.wikipedia.org/wiki/Libav#Fork_from_FFmpeg The github link is on mpv wiki. mpv is a descendant of mplayer and mplayer2 (the latter being mostly dead). IMHO mpv is the best media player for any OS (lightweight, snappy, reads everything, better options and CLI than mplayer*, etc.).

When converting video to gif, I always use palettegen, e.g. ffmpeg -i input.mp4 -filter_complex "fps=15,scale=640:-2:flags=lanczos,split[a][b];[a]palettegen=reserve_transparent=off[p];[b][p]paletteuse=dither=sierra2_4a" -loop 0 output.gif See also: this blog post from 10 years ago [1] [1] https://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html

I'm not sure if Kostya's account is truthful. He has a huge axe to grind against ffmpeg https://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html IIRC, his "LibAV" fork was malicious and his people lied a lot to the community ("ffmpeg is now deprecated!"). Ultimately, they failed, but I see a lot of their rhetoric and resentment in Kostya's post today.

Brings back memories. There was a time when the fork, libav, became the default on Ubuntu, and ffmpeg commands would say "this command is no longer maintained" or so. That was where I learned that there was a fork, and I thought ffmpeg was going to die as a result because there was heavy development activity on libav compared to ffmpeg initially. Surprise, ffmpeg outlived its fork! This post talks about the situation back then: https://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

Indeed, the Zig build system includes a package manager. Fetching, configuration, compilation, and installation are all 1 command: zig build Furthermore, C and C++ code can participate in the Zig package ecosystem. For example, here is ffmpeg packaged for consumption by a Zig project: https://github.com/andrewrk/ffmpeg Why not use a system package? Well, because the user's system might not have such a package. They might be on Windows, for example. Or their package might be out of date. [Or the system might have chosen sides in a nasty fork war](http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html). So, while system packages are nice for end users, they might not always satisfy the needs of upstream application developers.

libav was the fork [1], and libav is dead now [2,3] (and many developers returned to ffmpeg). libav was forced to rename their project because Fabrice Bellard, still owner of the trademark and the ffmpeg.org domain, did not hand it over. ffmpeg put in much effort retain compatibility with libav, mostly by merging all their changes wholesale, while libav ignored ffmpeg, including and most crucially, their security fixes [4]. [1] http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html [2] https://www.libav.org/ [3] https://www.phoronix.com/news/FFmpeg-Back-In-Debian [4] https://j00ru.vexillium.org/2014/01/ffmpeg-and-the-tale-of-a-thousand-…

I wrote something similar a while back: http://blog.pkh.me/p/15-the-music-classifying-nightmare.html

If you check this link[0] you can see most of your statement about FFmpeg merging everything and Libav being all about clean code is just completely false. Apparently lots of hardcoding and weird NIH on the Libav side, and a biased Ubuntu package maintainer to boot. [0] http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

Doesn't ffmpeg have a reputation for bad code merge practices? I've heard libav[1], a fork of ffmpeg has much better focus on code quality. Note that ffmpeg frequently merges any new code from libav. So ffmpeg is almost a superset of the both. For anyone wondering why this is, here is a good explanation.[2] [1]:https://www.libav.org/ [2]:http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

forking of a community is absolutely deadly Could you expand on this a bit? I imagine it depends on who "deadly" applies to, but forking is just one of the ways centralized decision makers who are, erm.. not making very good decisions can be worked around. Look at what happened to ffmepg/libav - by any analysis, the fork resulted in better software: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

It’s very complicated there, too, though. As this article [1] shows, even with animated gifs you have often unstable dithering with artifacts somewhere in the image. [1] http://blog.pkh.me/p/21-high-quality-gif-with-ffmpeg.html

Some info: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html There are more links in that post to fill you in on the details.

The fork happened for human reasons (management-related) rather than technical. See http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html and http://lwn.net/Articles/423703/

Also, according to a ffmpeg contributor [1] (who joined after the schism) they just refused to merge anything by ffmpeg, often doing identical functionality from scratch (because users wanted it after seeing it in ffmpeg). Meanwhile ffmpeg merged basically everything from libav. Furthermore ffmpeg made an effort to provide compatibility, even for stuff where libav intentionally broke compatibility. So basically ffmpeg benefitted from all the work put into libav but not the other way around. Seems to me that they brought this upon themselves. [1]: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

The reality is not like you describe it. The debian package maintainer of ffmpeg was/is one of the libav guys and decided to replace ffmpeg with libav. Judging by several frustrated comments in this thread, it has obviously been a hurtful decision. There are a few writeups of the situation on the web, here's one: http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html

No, check out http://blog.pkh.me/p/13-the-ffmpeg-libav-situation.html. While Libav left with the server, bug tracker, etc., the FFmpeg project was restoring itself, with the help of some VideoLAN people (the FFmpeg sources are now hosted on git.videolan.org). Michael also started to merge the Libav changes back into FFmpeg every 1-2 day, with a lot of forgotten, previously rejected, sometimes controversial features, or in stand-by such as ffmpeg-mt. The main point here is that the fork stimulated the competition, and FFmpeg became a way better (IMHO) and more complete project. Also, I must say the leader's attitude completely changed, in a very good way. This is certainly one of the most positive thing that came out of that war.