Lines Matching refs: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.
159 This setting is designed to improve the compression ratio for files with
165 set advanced parameters to maximum compression.
172 This is effectively dictionary compression with some convenient parameter
182 to improve compression ratio marginally at the cost of speed. Using
183 '--single-thread' above level 15 will lead to lower compression
186 Note: for level 19, you can get increased compression ratio at the cost
190 `zstd` will periodically synchronize the compression state to make the
192 There is a negligible impact to compression ratio,
193 and a potential impact to compression speed, perceptible at higher speeds,
205 do not store dictionary ID within frame header (dictionary compression).
214 This is also used during compression when using with `--patch-from=`. In this case,
223 This information will be used to better optimize compression parameters, resulting in
224 better and potentially faster compression, especially for smaller source sizes.
227 will be when optimizing compression parameters. If the stream size is relatively
228 small, this guess may be a poor one, resulting in a higher compression ratio than
230 Exact guesses result in better compression ratios. Overestimates result in slightly
231 degraded compression ratios, while underestimates may result in significant degradation.
237 Enabling this feature can decrease compression speed by up to ~10% at level 1.
265 remove source file(s) after successful compression or decompression.
270 keep source file(s) after successful compression or decompression.
300 support, zstd can compress to or decompress from other compression algorithm
319 …shows the default compression parameters that will be used for a particular input file, based on t…
342 They set the default compression level and number of threads to use during compression, respectivel…
346 `ZSTD_CLEVEL` just replaces the default compression level (`3`).
348 …_NBTHREADS` can be used to set the number of threads `zstd` will attempt to use during compression.
354 `-#` for compression level and `-T#` for number of compression threads.
359 `zstd` provides 22 predefined regular compression levels plus the fast levels.
360 A compression level is translated internally into multiple advanced parameters that control the beh…
362 These advanced parameters can be overridden using advanced compression options.
367 taken from the selected or default compression level.
382 improves compression ratio.
393 Bigger hash tables cause fewer collisions which usually makes compression
394 faster, but requires more memory during compression.
403 improves compression ratio.
404 It also slows down compression speed and increases memory requirements for
405 compression.
416 compression ratio but decreases compression speed.
423 Larger search lengths usually decrease compression ratio but improve
433 A larger `targetLength` usually improves compression ratio
434 but decreases compression speed.
438 Impact is reversed: a larger `targetLength` increases compression speed
439 but decreases compression ratio.
448 Reloading more data improves compression ratio, but decreases speed.
464 Larger values will improve compression speed. Deviating far from the
465 default value will likely result in a decrease in compression ratio.
474 Bigger hash tables usually improve compression ratio at the expense of more
475 memory during compression and a decrease in compression speed.
484 Larger/very small values usually decrease compression ratio.
494 Larger bucket sizes improve collision resolution but decrease compression
501 The following parameters sets advanced compression options to something
507 Specify the size of each compression job.
509 Each compression job is run in parallel, so this value indirectly impacts the nb of active threads.
510 Default job size varies depending on compression level (generally `4 * windowSize`).
519 `zstd` offers _dictionary_ compression,
523 Then, during compression and decompression, reference the same dictionary,
535 Since dictionary compression is mostly effective for small files,
554 Use `#` compression level during training (optional).
555 Will generate statistics more tuned for selected compression level,
556 resulting in a _small_ compression ratio improvement for this level.
614 in size until compression ratio of the truncated dictionary is at most
615 _shrinkDictMaxRegression%_ worse than the compression ratio of the largest dictionary.
669 The `zstd` CLI provides a benchmarking mode that can be used to easily find suitable compression pa…
670 …std -b [FILE(s)]` will benchmark `zstd` for both compression and decompression using default compr…
679 benchmark file(s) using compression level #
681 benchmark file(s) using multiple compression levels, from `-b#` to `-e#` (inclusive)
695 …compression levels, benchmarking is also compatible with other parameters, such as number of threa…