Lines Matching refs:compression

18 `zstd` is a fast lossless compression algorithm and data compression tool,
21 `zstd` offers highly configurable compression speed,
23 and strong modes nearing lzma compression ratios.
92     Benchmark file(s) using compression level #
104     `#` compression level \[1-19] (default: 3)
106     unlocks high compression levels 20+ (maximum 22), using a lot more memory.
113     This setting is designed to improve the compression ratio for files with
119     switch to ultra-fast compression levels.
121     The higher the value, the faster the compression speed,
122     at the cost of some compression ratio.
123     This setting overwrites compression level if one was set previously.
124     Similarly, if a compression level is set after `--fast`, it overrides it.
132     Does not spawn a thread for compression, use caller thread instead.
134     In this mode, compression is serialized with I/O.
135     (This is different from `-T1`, which spawns 1 compression thread in parallel of I/O).
140     do not store dictionary ID within frame header (dictionary compression).
158     remove source file(s) after successful compression or decompression
160     keep source file(s) after successful compression or decompression.
166     support, zstd can compress to or decompress from other compression algorithm
187 `zstd` offers _dictionary_ compression,
191 Then during compression and decompression, reference the same dictionary,
210     Use `#` compression level during training (optional).
211     Will generate statistics more tuned for selected compression level,
212     resulting in a _small_ compression ratio improvement for this level.
269     benchmark file(s) using compression level #
271     benchmark file(s) using multiple compression levels, from `-b#` to `-e#` (inclusive)
281 **Methodology:** For both compression and decompression speed, the entire input is compressed/decom…
286 `zstd` provides 22 predefined compression levels.
287 The selected or default predefined compression level can be changed with
288 advanced compression options.
291 taken from the selected or default compression level.
305     improves compression ratio.
316     Bigger hash tables cause less collisions which usually makes compression
317     faster, but requires more memory during compression.
325     improves compression ratio.
326     It also slows down compression speed and increases memory requirements for
327     compression.
337     compression ratio but decreases compression speed.
344     Larger search lengths usually decrease compression ratio but improve
354     A larger `targetLen` usually improves compression ratio
355     but decreases compression speed.
359     Impact is reversed : a larger `targetLen` increases compression speed
360     but decreases compression ratio.
369     Reloading more data improves compression ratio, but decreases speed.
376     Exception : the maximum compression level (22) has a default _ovlog_ of 9.
383     Bigger hash tables usually improve compression ratio at the expense of more
384     memory during compression and a decrease in compression speed.
393     Larger/very small values usually decrease compression ratio.
403     Larger bucket sizes improve collision resolution but decrease compression
414     Larger values will improve compression speed. Deviating far from the
415     default value will likely result in a decrease in compression ratio.
420 Select the size of each compression job.
422 Default value is `4 * windowSize`, which means it varies depending on compression level.
428 The following parameters sets advanced compression options to those of