Questions tagged [compression]
Lossless and lossy data compression: algorithms and utilities.
21
questions
4
votes
3
answers
602
views
Compressing a list of records so it can be uncompressed elementwise [closed]
I have a bunch of lists of generic items (byte sequences) and I would like to store them compressed. There are several tools out there that run on modern computers to compress data into as-small-as-...
- 2,642
26
votes
3
answers
7k
views
When did HTTP start compressing text?
HTML tends to compress well, typically consisting of text interspersed with repetitive tags. Transparently compressing it for download is a fairly obvious optimization to save bandwidth.
When did Web ...
- 58.4k
15
votes
1
answer
866
views
What type(s) of compressed files was the MS-DOS EXPAND command able to decompress?
What type(s) of compressed files was the MS-DOS EXPAND command able to decompress?
And what command was its counterpart?
- 253
22
votes
7
answers
4k
views
Disk compression risks in MS-DOS
Continuing my nostalgia reading of Dan Gookin's DOS For Dummies, there is a section that literally advises against compression programs like DriveSpace and calls it a solution to a problem not some ...
- 1,925
24
votes
6
answers
9k
views
Why was video, audio and picture compression the poorest when storage space was the costliest?
"Full-motion video" sequences in PC and console games in the 1990s were bad-looking, in spite of taking huge amounts of storage space. Same thing with random short video clips that I ...
- 283
14
votes
1
answer
577
views
What are these compression types in the ARC file format?
The file format of the SEA ARC compression tool, also used by the PKWare PKARC tool, allowed the following compression types:
Packing (RLE encoding)
Squeezing (static Huffman coding)
Crunching (LZW)...
- 18.3k
9
votes
1
answer
963
views
Was there a compression program based on the Mayne-James algorithm?
Before the advent of Lempel-Ziv family compression algorithms, there was an algorithm for "Information compression by factorising common strings" by A. Mayne and E. B. James (1975), based on ...
- 18.3k
13
votes
5
answers
2k
views
Compression techniques used in old ZX Spectrum tapes
Many ZX Spectrum games* (and demos) would improve loading time and save space in the tape using rudimentary compression. During decompression, the game would display "decrunching" for ...
- 1,999
8
votes
0
answers
434
views
What is the origin of executable compression?
According to the wikipedia article on the topic, the earliest executable compressor listed is Realia Spacemaker for IBM PC (since 1982, written by Robert B. K. Dewar, SM.COM, signature "MEMORY$&...
- 18.3k
6
votes
1
answer
955
views
What data compression did Donkey Kong Country use?
Donkey Kong Country was among the most ambitious, popular and influential of Super Nintendo games. Technically, its big trick was taking animations rendered on Silicon Graphics workstations and ...
- 58.4k
5
votes
1
answer
205
views
What was the first database to start compressing in situ?
The obvious way for a database to store data is with each record in a contiguous chunk, and each field having a fixed size and offset in the record. Joel Spolsky praises that way of doing things:
...
- 58.4k
6
votes
1
answer
365
views
Reconstructing uncompressed program from compressed tape image
I have a C64 program in a .t64 file. If I load it into an emulator, what I see is that it loads into a cracktro, which then proceeds to uncompress (taking several seconds at 100% speed) the original ...
- 2,642
1
vote
3
answers
320
views
How do I interpret these instructions for decompressing game data? [closed]
I'm trying to write a tool for the 1994 SNES game Super Metroid that creates "out of bound" maps for each the game's rooms. To do so, first I need to extract the tile-by-tile data of each room. For ...
- 663
5
votes
2
answers
1k
views
Could early nineties PCs access raw CD bitstream?
In the early nineties, as discussed in What specific technical advance(s) allowed PCs to play "Full-screen full-motion" video? it became commonplace for PC games to use the storage capacity ...
- 58.4k
20
votes
2
answers
4k
views
How did the Sega CD decompress video?
In the early nineties, Sega released the Sega CD, a.k.a. Mega CD, an add-on that attached a CD-ROM drive to the Mega Drive a.k.a. Genesis. Its primary or at least most conspicuous use was for full-...
- 58.4k
5
votes
1
answer
314
views
Can't install El-Fish on MS-DOS 6.22
El-Fish is a fish tank "game", where you have virtual fish on your screen. The game has no goal, it's more like an interactive screen saver.
I got my version from a number of different sources, one ...
- 151
24
votes
5
answers
5k
views
How well known and how commonly used was Huffman coding in 1979?
Infocom's Z-Machine, designed in 1979, compresses text using a basic 5 bit code which is not very efficient in practice, achieving maybe a 1.5:1 compression ratio.
Huffman coding would be far more ...
- 747
17
votes
2
answers
2k
views
What is the difference between DriveSpace and DoubleSpace?
DriveSpace is the successor to DoubleSpace. Both are DOS systems that mount a Compressed Volume File as a drive, allowing ordinary programs to interface with a compressed drive without an intermediate ...
- 18.5k
10
votes
1
answer
1k
views
What is the history of data compression tools on personal computers?
On UNIX, the progression of the most widespread data compression programs was as follows:
(AFAIR: Pre System V) compact (suffix .C), dynamic Huffman coding
(AFAIR: introduced in System V) pack (...
- 18.3k
24
votes
4
answers
5k
views
Why does MP3 audio decoding overwhelm retro CPU's?
Many retrocomputers from the late 80s and early 90s had audio DAC hardware support. This includes the Amiga, Classic Macintosh, and PC's with SoundBlaster add-on cards. Despite the fact that the MP3 ...
- 60.1k
23
votes
2
answers
6k
views
How to convert Amiga DMS to ADF?
Our demoscene group managed to release only one demo before it fell apart, but these being the early days of the Internet in my country, and me getting lucky with obtaining access to it and creating ...
- 7,065