the #JPEG #file-format can actually include a sequence of image updates
on 02026-07-18The #PBF format for #OpenStreetMap: “It is about half of the size of a gzipped planet [in OSM XML format] and about 30% smaller than a bzipped planet. It is also about 5x faster to write than a gzipped planet and 6x faster to read than a gzipped planet. The format was designed to support future extensibility and flexibility.
The underlying file format is chosen to support random access at the 'fileblock' granularity. Each file-block is independently decodable and contains a series of encoded PrimitiveGroups, with each PrimitiveGroup containing ~8k OSM entities in the default configuration.”. #file-format
on 02025-11-27In 01999 people thought #PNG was dead! #file-format
on 02025-11-26Yeah, even #RFC 2083 #PNG didn’t support uncompressed image data: “Compression method is a single-byte integer that indicates the method used to compress the image data. At present, only compression method 0 (deflate/inflate compression with a 32K sliding window) is defined. All standard PNG images must be compressed with this scheme. The compression method field is provided for possible future expansion or proprietary variants.” #file-format
on 02025-11-26#PNG doesn’t support uncompressed image data, only deflated data. #file-format
on 02025-11-26#TeX #fonts metrics format. #file-format
on 02025-11-26#PDF scan of an early TUGboat introducing the new non-36-bit #TeX #fonts metrics format TFM. #file-format
on 02025-11-26discussion of F3 #file-format
on 02025-11-05#PDF #paper #toread about F3 “future-proof” #file-format by Wes McKinney and a bunch of researchers from Tsinghua. It’s supposed to displace Parquet I guess?
on 02025-11-05#HDF #file-format book with Python
on 02025-11-05#small-is-beautiful #GUI library #LVGL supports the #glTF file format for #3D-models. #file-format
on 02025-11-05#F3 #file-format discussion: “they’ve addressed a lot of the shortcomings of Parquet which is very exciting” including Wes McKinney #toread
on 02025-10-02#Valgrind #documentation on the Callgrind ASCII #file-format
on 02025-09-09#archival of the #WordStar #file-format
on 02025-08-27#video on a conference presentation on the “state of libre graphics” including a new “boring” #file-format for #fonts.
on 02025-05-28the specification for JP Software’s #4DOS DESCRIPT.ION #file-format #standards
on 02025-03-07#CodingAdventure #video on sound, the Fourier transform, fluid dynamics, etc. Starts with .wav #file-format, showing #C-sharp source code. He’s using programming #ligatures, perhaps of interest as a use spotted in the wild. He simulates propagating waves through a two-dimensional fluid simulation from a reciprocating membrane to a “microphone”. Justifies the Fourier transform with visualizations. “My faith in this implementation is as bottomless as a puddle.” Also explains the Nyquist frequency and spectral leakage, again with visualizations.
on 02024-09-10the #Hofstadter #gridfonts #font data, with 287 fonts in some kind of hexadecimal #file-format that doesn’t seem to be documented
on 02024-01-14the #Hershey-fonts #file-format #fonts
on 02024-01-12#LZ4 #compression #file-format explained: the literal length and match length are each packed into a 4-bit field in a “token” byte, but if they’re more than 14, the 4-bit field is 15 and extra bytes are appended (elsewhere, in the case of match length) to sum up to the correct value with the 15; the sequence of extra bytes is terminated by the first byte that’s less than 255.
on 02024-01-12#file-format documentation for #netpbm P3 and P6 formats (.ppm)
on 02023-12-29the documentation for the "Netpbm" image manipulation toolkit, including #file-format documentation
on 02023-12-29more about the #Git packfile #file-format
on 02023-12-12Explanation of the #Git packfile #file-format with Rust code to decode it
on 02023-12-12#Git packfile #file-format
on 02023-12-12overview of the #MJPEG #file-format
on 02023-12-04more on the #MJPEG #file-format; it has native support in Firefox, Chromium, the PlayStation Portable (in 480×272 in an AVI container), the Wii, the Nikon D90 DSLR camera from 02008, etc.
on 02023-12-04#PDF on the #MJPEG #file-format used by, for example, the Zoran ZR36067 MJPEG codec chip, but really just focused on lavrec, lav2yuv, etc., and not the format itself
on 02023-12-04The #Golang "Gob" #serialization #file-format
on 02023-12-04The #ADPCM #audio #codec has problems in #Godot importer for the #WAV #file-format, but apparently it’s still reasonably popular.
on 02023-08-09Dominic Szablewski’s #image #compression #file-format: “[Quite OK Image] is fast. It losslessly compresses images to a similar size of PNG, while offering 20x-50x faster encoding and 3x-4x faster decoding. QOI is simple. The reference en-/decoder fits in about 300 lines of C. The file format specification is a single page PDF.” Again, maybe worthwhile for the Zorzpad.
on 02023-08-09Dominic Szablewski’s #audio #DSP #codec #file-format "qoa" for fast, lossy #compression: “[Quite OK Audio] is fast. It decodes audio 3x faster than Ogg-Vorbis, while offering better quality and compression (278 kbits/s for 44khz stereo) than ADPCM. QOA is simple. The reference en-/decoder fits in about 400 lines of C. The file format specification is a single page PDF.” This might be worthwhile for low-CPU-power audio recorders and maybe the Zorzpad, especially for games. Now supported systemwide in SerenityOS. Based on 4-tap linear prediction? With the weights varying over time?
on 02023-08-09ImageMagick can render text into an image and produce XBM or XPM output, which are suitable for using with #include in a #C program. It can use both #TrueType outline fonts and bitmap formats like #BDF or #PCF. This is potentially a kludgy alternative to understanding the #font #file-format
on 02023-06-02George Williams wrote the best page about the #PCF #font #file-format except for the CircuitPython implementation.
on 02023-06-02#PCF #font #file-format in Kaitai Struct.
on 02023-06-02Adafruit is converting #BDF to #PCF #font #file-format using #Wasm
on 02023-06-02"bitmap_font" is a #CircuitPython #font library supporting #BDF and #PCF #file-format
on 02023-06-02#CircuitPython implementation of the #PCF #font #file-format; there's also a #BDF implementation. MIT-X11-style license.
on 02023-06-02A #file-format converter, or really #font rasterizer, from #TrueType to #BDF, for #CircuitPython
on 02023-06-02the #PCF #font #file-format. Not a lot of great info on this page right now
on 02023-06-02a #PCF to #BDF #font #file-format converter
on 02023-06-02Ange Albertini’s color-coded diagram of the ELF #file-format
on 02017-04-12#Bellard’s Better Portable Graphics #file-format to replace JPEG with much better lossy compression based on HEVC, with a decoder in JS, based on HEVC.
on 02016-07-24comparison of image #file-format overhead.
on 02016-07-24The WMF “Windows Metafile” #file-format.
on 02015-11-16CBOR is a new binary #serialization #file-format: basically binary JSON plus byte strings, integers, cyclic references, and extensible type tags, designed for “decades of use”. Prefix-decodable but not suffix-decodable.
on 02015-09-29