SYNOPSIS
advpng [-l, --list] [-z, --recompress] [-0, --shrink-0]
[-1, --shrink-fast] [-2, --shrink-normal [-3, --shrink-extra]
[-4, --shrink-insane] [-i, --iter N]
[-f, --force] [-q, --quiet]
[-h, --help] [-V, --version] FILES...
DESCRIPTION
The main purpose of this utility is to recompress png files to get the smallest possible size.Please note that this utility is not able to read a generic file. It's granted to be able to read only the files generated by the AdvanceMAME emulator.
To compress the files this utility uses the following strategies:
- Remove all ancillary chunks.
- Concatenate all the IDAT chunks.
- Use the 7zip Deflate implementation.
OPTIONS
- -l, --list FILES...
- List the content of the specified files.
- -z, --recompress FILES...
- Recompress the specified files. If the -1, -2, -3 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.