AdvanceCOMP Deflate Compression Utility

1 Synopsis

advdef [-z, --recompress] [-0, --shrink-store]
    [-1, --shrink-fast] [-2, --shrink-normal] [-3, --shrink-extra]
    [-4, --shrink-insane] [-i, --iter N]
    [-f, --force] [-q, --quiet]
    [-h, --help] [-V, --version] FILES...

2 Description

The main purpose of this utility is to recompress the data present in the .png, .mng, .gz, .tgz and .svgz files.

The internal structure of the files isn't changed. Only the compressed data is modified.

3 Options

-z, --recompress FILES...

Recompress the specified files. If the -1, -2, -3, -4 options are specified it's used the smallest file choice from the previous compressed data and the new compression. If the -0 option is specified the file is always rewritten without any compression.

-0, --shrink-store

Disable the compression. The file is only stored and not compressed. The file is always rewritten also if it's bigger.

-1, --shrink-fast

Set the compression level to "fast" using the zlib compressor.

-2, --shrink-normal

Set the compression level to "normal" using the 7z compressor. This is the default level of compression.

-3, --shrink-extra

Set the compression level to "extra" using the 7z compressor. You can define the compressor iterations with the -i, --iter option.

-4, --shrink-insane

Set the compression level to "insane" using the zopfli compressor. You can define the compressor iterations with the -i, --iter option.

-i, --iter N

Define an additional numer of iterations for the 7z and zopfli compressors for modes -3 and -4. More iterations usually give a better compression, but may require a lot more time. Try for example with 10, 15, 20, and so on.

-f, --force

Force the use of the new file also if it's bigger.

4 Limitations

The advdef program cannot be used to recompress huge files because it needs to allocate memory for both the complete compressed and uncompressed data.

5 Copyright

6 See Also

advpng(1), advmng(1), advzip(1), gzip(1), bzip2(1)