Lex Fridman Podcast
#496 – FFmpeg: The Incredible Technology Behind Video on the Internet
06 May 2026
Chapter 1: What is FFmpeg and why is it considered essential for video on the internet?
The following is a conversation all about FFmpeg and VLC with Jean-Baptiste Kempf and Kieran Cunha. FFmpeg is an open source software system that is the invisible backbone behind YouTube, Netflix, Chrome, VLC, Discord, and basically every platform that touches video or audio on the internet. It can decode, encode, transcode, stream, and play almost any video or audio format ever created.
To me, it is one of the most incredible software systems ever developed. And it's all done by volunteers. VLC is also a legendary piece of software. It is an open-source media player that plays basically anything you throw at it, any format, any platform, no ads, no tracking.
It has been downloaded over 6 billion times, and again, for me, it has been one of my favorite pieces of software ever, with the most legendary logo, which I, of course, had to honor in this conversation by wearing the... VLC traffic cone hat the whole time.
So again, above all else, thank you to the incredible volunteer engineers who put their heart and soul into this code that has been used and loved by billions of people. Thank you. and about the two great engineers and human beings I'm talking to in this episode. Jean-Baptiste is the president of Videoland and is a key figure behind VLC and FFmpeg.
Kieran is a longtime Kodak engineer, FFmpeg contributor, and the man behind the now infamous FFmpeg account on Twitter, X, that I recommend watching. everybody follow for the memes and for the unapologetic celebration of open source and great low-level software engineering.
Let me also say that it's inspiring and humbling that so much of modern civilization rests on software built by people who are not chasing fame or money, but are obsessed with the craft of engineering. We live in a world where billions of people consume video every day without ever thinking about the invisible machinery underneath it. But that machinery matters.
Open source infrastructure matters. It is one of the great examples of human beings quietly collaborating across borders to build something useful, durable, and elegant for the rest of us. And so this conversation is not just about Codex and media pipelines. It is also about the deeper spirit of engineering and generosity that makes projects like FFmpeg possible. Again, I can never say it enough.
Thank you. And now, a quick few second mention of a sponsor. Check them out in the description or at lexfriedman.com slash sponsors. It is, in fact, the best way to support this podcast.
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Chapter 2: What are the unique features of VLC as a media player?
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built for large, complex code bases. Huge number of cooperative agents, really optimized for huge code bases. Optimized for scaling speed when you're talking about a very large number of agents working together. And that's the big interesting question.
When you have a huge number of agents, a huge company, huge code base, how do you then, seen at the big picture code base level, have the growth and development, the evolution of that code base where a very large percentage of that code base is continuously worked on autonomously? The question is when you have a large code base,
that already delivers value, that already sells stuff, that already has a huge number of customers, how do you then use agentic engineering to continue adding features, continue improving, continue in the usual kind of development with the testing, with the security, all that kind of stuff?
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That's blitzy.com. This episode is also brought to you by BetterHelp, spelled H-E-L-P, help. Moving away from AI to the human. The human mind is still, to this day, out of reach of our understanding from the perspective of creating intelligence. There are so many intricate psychological complexities to the mind, which I think attributes to what makes humans incredibly special.
But those complexities get all tangled up in ways that are counterproductive. And so they need to be untangled in a I'm a big fan of talk therapy as a set of tools as a methodology for untangling the complexities of the human mind. The easy, discreet, affordable way of doing that is BetterHelp. That's why I keep recommending it.
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As I mentioned already about humans, humans are complicated. And customer service is ultimately about looking at each individual human and really listening. That's what I try to do with the podcast, to truly listen to each individual person, whether we're talking about a super technical topic or we're talking about the big issue. questions of the human condition.
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Chapter 3: How does open source contribute to the development of VLC and FFmpeg?
And then, funnily, at one Videoland conference, we made a competition to make the weirdest and most horrible file ever and see if VLC could play it. What did it end up being? What's the file? It was an MKV file made by Derek, which each of the frame was changing resolution, aspect ratio, rotation, and it was like... Did it work? Yes.
And there was another one where the whole video was actually animated subtitles, right? SSA, right? So each frame was a black frame, but on top of that, there was a subtitle that was animated for each frame.
There was a file that's a valid zip and a valid MP3 at the same time or something like that.
So yeah, we'd made a competition of stupid files. And it worked. It opened all of the stupid files. Yes. By the way... For people who are not familiar, I am wearing a hat. Would it be fair to say this is the best, worst logo of all time, the cone?
Yeah, by far, right? The logo of VLC is so iconic, right? Like, we are a team with a small number of people, and the icon is known everywhere. I go to middle of nowhere in India or in China, people know the cone, right? Yeah. 25% of the website traffic that comes to our main website is ConePlayer, right? So many people don't know VLC, right? They know the ConePlayer.
That's the thing that Google for is ConePlayer. Yeah, they go on Google and they put ConePlayer and they download VLC, right? So that's iconic. And once we tried to change it as a joke, right? We said it was going to be a type of caterpillar game.
construction and we said that during april 1st and we had around 10 000 emails saying no don't change the logo and so on right so it's so iconic right it's so distinctive right if you want to do a video player you're going to put a play button on the tv right and that's a youtube youtube logo right it's an original this one is orange right very bright uh and and it's
weird and it's ridiculous and it's absurd and it's hilarious it becomes meme and meme becomes culture and you keep it and you know about it and you know that in 20 years like you still have going to have the cones and remember oh yeah that was a video player yeah and we'll talk about you know the the mission of ffmpeg being a kind of the archival aspect of it.
So you can think about a thousand years from now, we'll have all these videos that only VLC can open. Human civilization has already destroyed itself multiple times. And the only thing that will remain is this like, you know, the cockroaches will be crawling around and it'll be the VLC logo with some of the archival footage that VLC can open.
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Chapter 4: What contributions can young developers make to open source projects?
This is a 16-year-old, some of his first contributions to FFmpeg. Actually doing and putting some of these quote-unquote security researchers to shame by actually finding issues and fixing them and being 16. There's no barriers. There's no barriers to you have to study at college under this person and understand these. You can learn C, and let's be honest, it's from the K&R book.
Learn C. You can learn assembly. We'll talk about that maybe a bit later. You can contribute to world-class technologies.
In VLC, one of the oldest contributors is called Felix. He's the one doing everything on Mac and iOS.
Chapter 5: How does FFmpeg handle security issues compared to traditional security researchers?
He's starting working on VLC. He was 16. We had a guy called Edward Wong, who used to be a Google Summer of Code student who stayed... for three years around video LAN, he was 14, right? And part of Google Summer of Code and Google Code-In, which were programs where basically we have students or high school, we wrote a ton of assembly for x264 and for VLC and for FFmpeg, right?
So everyone can contribute.
And he also did a good job because he didn't play the alarmist CVE heist, create a CVE, which is like a public exposure of security and do these big, scary, red 7.5 priority. He just fixed an issue in Git after three days and just fixed it. He didn't need to go and play a big security drama about it. And I think... I posted, you know, the kids are all right.
Whereas there's, you know, I'm not saying all security people do this, but there is a portion of the security community, as Alex said, that likes to hype themselves up by creating drama. They would have happily raised, this is a high priority CVE 8.0 or whatever on an issue that actually was in Git. It wasn't even in a release. It was in development and three days later was fixed.
Well, I just want to put a little bit of love out there, even to the bigger community. Much love and respect to Google engineers. Like you said, they're some of the best software engineers in the world, and they do contribute a lot even on the security front. And also, you know, I'm a big fan of Theo. Much love to Theo.
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Chapter 6: What motivates developers in the open source community?
He was part of this debacle and drama a little bit. I think when you just zoom out,
on the grand arc of human history the drama contributed positively to everybody involved donations went up it brought more attention to the topic allowed uh everybody to bicker in a way that ultimately uh got them to figure out whatever fanbag is all about so the way the way we looked at this is like it's a rap battle at the end of the day no but it is we say stuff we say stuff
Yeah. But we can, we can leave it on the X is a perfect place for, you know, international rap battle. You say stuff, I say stuff about your mama, but it doesn't mean, you know, I'm going to have an actual personal issue with her. Yeah. And that's what it looks like. The Theo situation, you know, JB can maybe expand when a little bit too far and there was a little bit.
You know, it's just a bit of fun. It's just a bit of rap battle. It's WWE. You know, everyone's having a bit of fun on X. It doesn't need to be taken seriously. You know, the teenagers thing. So that guy was a Google employee saying, hey, you know, there are other ways to run an open source business. You know, just have a bit of fun, you know. That's what the point of this account is.
And furthermore, if you can teach people about the ways of open source projects, assembly, et cetera, by doing that, I think there's a lot to be offered here. It's not... dunking on people for dunking sake. It's showing actually the story that I think X learned is these are not big corporate open source projects.
This is not Kubernetes where there's, you know, hundreds, maybe thousands of people paid to develop this stuff. These are just people in their basements in their spare time. And if you can address that topic in a fun and entertaining way, I think that that's the good thing. And that's the value of X and the reach we have.
And to be honest, right, like even at Google, Google is one entity, but so many different people, right? And there is a ton of Google engineers we work with all the time. And even like Google from YouTube to Chrome to Chrome Media to the rest of Google, those are very different type of entities. But what we do is... efficient. And for example, for Theo, right, it went a bit too far.
I had him, like, I call everyone down, I had him on the phone, we say, okay, like, this goes too far, and so on. But in the end, yeah, it's a hard battle, but it's positive for the project. It's like the awareness we have on open source, and I mean, true open source from communities, right, not is increased dramatically in the last two years. And this is useful.
What do you think motivates all the incredible contributors that we've been talking about? What's the engine? It's so interesting to see. Like you said, they're sitting in the basement. What's the driver? What's the engine there?
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Chapter 7: What are the challenges of encoding and decoding video?
So for people who are just listening, we're looking at a bunch of humans running along a river. You have the reflection, a lot of really high information textures everywhere, the leaves and the lighting playing with the leaves and all of this.
You could show clearly that encoders with high PSNR will blur everything. And you could see, actually, I could turn on psychovisual stuff, I could turn off adaptive quantization, and it would just look so much better. But your metrics, and these metrics are, at the time, were considered so holy. These are the holy metrics that are untouchable. PSNR is the most important thing.
Can you speak to how do you measure psychovisual stuff? Like, how do you turn how pleasing a compression is for a human eye into a number? Is that even possible?
That's what Netflix have been trying to do with VMAF. They said they've used a machine learning model.
that's a more recent thing but back in when x86 was being developed that's by eye it was by eye it was developers on their laptops so it's not like even with big companies with professional screens or anything it's and that was actually one of the goals which was i don't the developers at the time lauren merit in particular is i don't want to test this on a thirty thousand dollar screen it's i want this to look good on someone's laptop at home
Yeah, brilliant. And there is another sample, which is a sample that is Planet Earth's Kila sample that I absolutely love. And you are going to see why. It's a ton of birds flying. And the more it goes, the more there are birds. And at the end, it's almost like... You have millions of birds. It's the most complex thing ever to encode, right?
And well, you're watching it on YouTube and you see how bad the YouTube encoding is actually, right? And this is like phenomenal to optimize and get perfect quality in a constant bitrate. There was a lot of optimization, mostly by Loren also, on anime, right? For a long time, anime was very badly encoded because there was a ton of bending, right?
And you see those issues, and there was a ton of things. So x264 is like, and today it's still the reference to any encoder, new encoder, AV1, AV2, VVC, HVC, everyone compares to x264.
One of my favorite films, Cinema Paradiso, I know the engineer who created the Blu-ray and he showed me the comparisons of X264 versus others and It's completely different. And I think a bunch of guys in the Blu-ray world started using x264. I think the big one was Chris Henderson from Warner Brothers. He did the whole French box set.
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Chapter 8: How does the future of codecs look with AV2?
One of the most amazing open source projects for subtitles is called AEG Sub. And it's a subtitle. It's done for anime, for South Asian and Japanese languages.
There are weird textures in anime that I don't think you get in real life content. I think that was a key one, which was optimizing these weird textures that you get because anime is not done in a normal fashion.
Yeah, the way you produce it is not, you mostly produce it like on screens, right? Since a bit of time and you have all those gradients, right? In colors, because they are very easy to produce digitally, very complex to produce in real life. And the subtitles also are very complex because you need to have often the Japanese and then you need to have the diacritics, right?
What we call the oribi, right? Which is the hiragana and the katakana for the kanji. And then, because of course, so that you have the official kanji, subtitling, but you also need the English subtitles or the French subtitles because you want to learn that, right? And there were so many things crazy on subtitles. And we had like crazy samples on subtitles that we've seen all around.
So this is an important part of the culture, but also because there was no official offering. There was no way of doing that.
Can you speak to the difference between H.264 and AV1 and then X.264 and David? This is this big step. Can you help people understand are some of the streaming sites moving more towards that direction of AV1? Let's be honest.
All of those codecs, since AV1, MPEG-2 video are the same concepts. The same concept about inverse transform, about intra-prediction, motion composite, entropy coding, all of them. However, each generation gives you a bump between 25% and 50% more compression for the same quality. And so you had the MPEG-2, you had the DivX area, you have H.264, which was changing. H.264 improved so much.
And then you had more. You had HEVC, you had VP9 at the same time of HEVC. VP9 is a bit similar to HEVC in terms of quality compression. But it's royalty free because in multimedia, there is a ton of patents and the licensing after H.264 became out of hand and could cost hundreds of millions of dollars per year. So it made no sense.
So Google did this VP9 and the Alliance for Open Media did this new codec called AV1. So you can imagine that AV1 saves between 40 and 60% less bandwidth than H.264 for the same quality, visual quality. At a given bitrate. At a given bitrate, right? So that's really like you increase the quality.
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