compression

Tom Scott explains why confetti and snow wreck video quality, using interframe compression and bitrate. He demonstrates it live by changing the quality on screen.

Mike Pound explains the discrete cosine transform and how it underpins JPEG compression. It is part two of Computerphile's JPEG series.

Tom Scott explains why hold music sounds worse than it used to, tracing it to old telephone exchanges and the audio compression applied by modern switches. It is a short visit to the Milton Keynes Museum.

A King of the Hill clip in which Hank-style character rants about saving images as PNG instead of JPEG after exporting from Windows Paint.

A condensed rendition of a project that re-uploaded one video to YouTube 1000 times, showing the accumulating compression artifacts. It pays homage to Alvin Lucier's I Am Sitting in a Room.

David Kriesel's FrOSCon talk on how Xerox scancopiers, due to JBIG2 compression, silently replaced digits in scanned documents. He walks through how he discovered the bug and why it is so dangerous.

Onslaught's Bad Apple 64 is a Commodore 64 demo that streams over 2000 frames of the Bad Apple animation from a single disk side at 12fps, with each frame packed to around 70 bytes.

David Kriesel's 31C3 talk, in German, on the discovery that Xerox scanner-copiers silently replace digits and letters in scanned documents. He explains how the bug stayed unnoticed in the wild for years.

Morphcat Games explains how they fit Micro Mages, a full-featured NES game, into 40 kilobytes. It covers compression of sprites and level layouts and other space-saving tricks.

Political economist Mark Blyth gives a lecture tracing two versions of capitalist 'software': the postwar Great Compression era and the neoliberal era from 1980 to 2008. He explains the bug that crashed the first and the design of the second.

The official music video for A$AP Mob's Yamborghini High featuring Juicy J, known for heavy datamoshing and glitch effects with hue shifting.

3Blue1Brown's animated visual introduction to the Fourier Transform, showing how a signal breaks into frequency components.

Monty Montgomery of Xiph.org gives real-time demonstrations of sampling, quantization, bit depth and dither using real audio equipment, including both digital analysis tools and vintage analog bench gear. It shows that sampled audio is not stair-stepped and corrects common misconceptions about digital audio.

The first of four short videos from Bill Hammack (engineerguy) introducing and giving the history of a 100-year-old mechanical computer, Michelson's harmonic analyzer. The series goes on to explain Fourier synthesis, analysis and operation of the machine.

3Blue1Brown shows how the uncertainty principle arises from Fourier transforms. A wave packet cannot be narrow in both position and frequency, so the principle is a property of waves rather than of measurement.

Tom Scott explains for Computerphile how Unicode and UTF-8 grew out of messy older character encodings to become the web's standard. It covers why the design works and how it handles worldwide text.

3Blue1Brown introduces Fourier series, from the heat equation to drawing arbitrary shapes with rotating circles. It builds a visual intuition for decomposing functions into sine waves.

Technology Connections explains why the superheterodyne radio has its name and how mixing frequencies lets it tune stations well. It walks through the underlying wave phenomena and algebra and why the design solved a hard tuning problem.

The first lecture of David MacKay's Cambridge course on information theory, pattern recognition and neural networks. It introduces the core ideas of his book Information Theory, Inference, and Learning Algorithms.

Timur Doumler's CppCon 2015 talk on how C++ is used in the audio industry. It covers the patterns and tools audio developers rely on, including handling real-time constraints.

A Justin Bieber song slowed down 800% with the PaulStretch program, turning a pop track into a long ambient drone.

Course outline for Stanford's online GNSS course, introducing how GPS works and the many uses of satellite navigation. The series pairs short lectures with backyard experiments using smartphones.

Tom Scott explains for Computerphile how floating point numbers work, why moving the binary point is fast, and why it handles money badly.

Edward Kmett's 2013 talk at Prezi in Budapest on succinct data structures, which store data in close to the information-theoretic minimum space while supporting fast queries. It ties together the research and walks through his Haskell succinct library.

MIT researchers show that sound can be recovered from silent video by analyzing tiny vibrations in objects such as a potato chip bag. It works even with consumer cameras by using rolling shutter.

Mathologer explains epicycles and complex Fourier series, inspired by an animation of Homer Simpson drawn with epicycles. It covers the shape of the Moon's orbit around the Sun and how to make your own epicycle drawings.

A spectrogram visualization of the sounds in a dial-up modem handshake, with an annotated image explaining each noise. It shows how the handshake's tones map to the negotiation steps.

A short clip of Venetian Snares' track 'Look' from Songs About My Cats (2001), shown as a spectrogram. The audio encodes an image in its frequency content.

A short demonstration of radioteletype (RTTY), a digital communication mode used in amateur radio, showing what the signal sounds like.

A six-minute clip of Adobe's MAX 2011 sneak peek showing a Photoshop prototype that removes motion blur from photos. The audience reacts with astonishment as blurry images become legible.

A Commodore 64 demo by Linus Akesson that fits video and music into 256 bytes, winning the Oldskool 4K Intro compo at Revision 2017. A technical write-up accompanies it.

SpaceX engineers present at NVIDIA's GPU Technology Conference on a multi-physics code that simulates the full-scale Raptor methane engine. It covers GPU-based turbulent combustion modeling with adaptive grids and wavelet compression.