Lines Matching full:compression
18 `zstd` is a fast lossless compression algorithm and data compression tool,
21 `zstd` offers highly configurable compression speed,
23 to strong modes with excellent compression ratios.
25 which remains roughly stable at all compression settings.
95 Benchmark file(s) using compression level _#_.
109 selects `#` compression level \[1-19\] (default: 3).
110 …Higher compression levels *generally* produce higher compression ratio at the expense of speed and…
111 A rough rule of thumb is that compression speed is expected to be divided by 2 every 2 levels.
115 unlocks high compression levels 20+ (maximum 22), using a lot more memory.
118 switch to ultra-fast compression levels.
120 The higher the value, the faster the compression speed,
121 at the cost of some compression ratio.
122 This setting overwrites compression level if one was set previously.
123 Similarly, if a compression level is set after `--fast`, it overrides it.
131 Use a single thread for both I/O and compression.
132 As compression is serialized with I/O, this can be slightly slower.
138 … Note 2: this mode is different from `-T1`, which spawns 1 compression thread in parallel with I/O.
144 `zstd` will dynamically adapt compression level to perceived I/O conditions.
145 Compression level adaptation can be observed live by using command `-v`.
159 This setting is designed to improve the compression ratio for files with
168 This is effectively dictionary compression with some convenient parameter
178 to improve compression ratio at the cost of speed.
180 Note: for level 19, you can get increased compression ratio at the cost
184 `zstd` will periodically synchronize the compression state to make the
186 There is a negligible impact to compression ratio,
187 and a potential impact to compression speed, perceptible at higher speeds,
199 do not store dictionary ID within frame header (dictionary compression).
208 This is also used during compression when using with `--patch-from=`. In this case,
217 This information will be used to better optimize compression parameters, resulting in
218 better and potentially faster compression, especially for smaller source sizes.
221 will be when optimizing compression parameters. If the stream size is relatively
222 small, this guess may be a poor one, resulting in a higher compression ratio than
224 Exact guesses result in better compression ratios. Overestimates result in slightly
225 degraded compression ratios, while underestimates may result in significant degradation.
231 Enabling this feature can decrease compression speed by up to ~10% at level 1.
259 remove source file(s) after successful compression or decompression.
264 keep source file(s) after successful compression or decompression.
294 support, zstd can compress to or decompress from other compression algorithm
313 …shows the default compression parameters that will be used for a particular input file, based on t…
336 They set the default compression level and number of threads to use during compression, respectivel…
340 `ZSTD_CLEVEL` just replaces the default compression level (`3`).
342 …_NBTHREADS` can be used to set the number of threads `zstd` will attempt to use during compression.
348 `-#` for compression level and `-T#` for number of compression threads.
351 ADVANCED COMPRESSION OPTIONS
353 `zstd` provides 22 predefined regular compression levels plus the fast levels.
354 A compression level is translated internally into multiple advanced parameters that control the beh…
356 These advanced parameters can be overridden using advanced compression options.
361 taken from the selected or default compression level.
376 improves compression ratio.
387 Bigger hash tables cause fewer collisions which usually makes compression
388 faster, but requires more memory during compression.
397 improves compression ratio.
398 It also slows down compression speed and increases memory requirements for
399 compression.
410 compression ratio but decreases compression speed.
417 Larger search lengths usually decrease compression ratio but improve
427 A larger `targetLength` usually improves compression ratio
428 but decreases compression speed.
432 Impact is reversed: a larger `targetLength` increases compression speed
433 but decreases compression ratio.
442 Reloading more data improves compression ratio, but decreases speed.
457 Bigger hash tables usually improve compression ratio at the expense of more
458 memory during compression and a decrease in compression speed.
467 Larger/very small values usually decrease compression ratio.
477 Larger bucket sizes improve collision resolution but decrease compression
488 Larger values will improve compression speed. Deviating far from the
489 default value will likely result in a decrease in compression ratio.
494 The following parameters sets advanced compression options to something
500 Specify the size of each compression job.
502 Each compression job is run in parallel, so this value indirectly impacts the nb of active threads.
503 Default job size varies depending on compression level (generally `4 * windowSize`).
512 `zstd` offers _dictionary_ compression,
516 Then, during compression and decompression, reference the same dictionary,
518 Compression of small files similar to the sample set will be greatly improved.
528 Since dictionary compression is mostly effective for small files,
547 Use `#` compression level during training (optional).
548 Will generate statistics more tuned for selected compression level,
549 resulting in a _small_ compression ratio improvement for this level.
607 in size until compression ratio of the truncated dictionary is at most
608 _shrinkDictMaxRegression%_ worse than the compression ratio of the largest dictionary.
662 The `zstd` CLI provides a benchmarking mode that can be used to easily find suitable compression pa…
666 benchmark file(s) using compression level #
668 benchmark file(s) using multiple compression levels, from `-b#` to `-e#` (inclusive)
680 **Methodology:** For both compression and decompression speed, the entire input is compressed/decom…
687 The <zstandard> format is specified in Y. Collet, "Zstandard Compression and the 'application/zstd'…