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better PNG files, fix WebP #101

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better PNG files, fix WebP #101

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@landfillbaby landfillbaby commented Feb 7, 2019

changed IDAT zlib header to max compression level, min decompression memory
truncated a further 4 bytes (the zlib adler32 sum)
added 2nd truncated version with IDAT length header 6 instead of 10 to account for truncation being inside the chunk now, same size but different error, one example i found that needs this is GIMP (both are ignored by most decoders anyway), not sure what the rules are here
(i meant to do this pr like a year ago and just found the files again)

landfillbaby and others added 2 commits February 7, 2019 18:29
changed IDAT zlib header to max compression level, min decompression memory
truncated a further 4 bytes (the zlib adler32 sum)
add version of above with IDAT length header 6 instead of 10
same size but different error (both are ignored by most decoders anyway)
new one is 30 bytes instead of 26, but it decodes at least
hopefully a .gitattributes will fix it
should probably check other formats too...
@landfillbaby landfillbaby changed the title better PNG files better PNG files, fix WebP Nov 4, 2019
@landfillbaby landfillbaby mentioned this pull request Nov 4, 2019
landfillbaby and others added 4 commits April 15, 2020 11:44
webp-odd.webp: manually removed RIFF even-byte-count padding
webp-vp8l.webp: the VP8L chunk without the RIFF, decodes with dwebp
webp-vp8l-raw.webp: the data from said chunk, dwebp accepts this too
why not use `-std=C90`?
since we're apparently going by whether the compiler fails rather than standards, which, no matter what version you use, say main is a function (it's just a plain int here) and newline at EOF is required
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landfillbaby commented Jul 24, 2022

update: there are 28-byte WebPs.
example: cwebp -z 9 of a single null RGBA pixel. webps.zip

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TPS commented Jul 24, 2022

Also, there's an updated c.c, apparently

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