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[fursund]

https://github.com/johannesvollmer/exrs/blob/66a247789004d974043300daf7bfc57c7d52a459/src/compression/mod.rs#L200

We're hitting in issue where channels are mixed between half and float, and it seems it might fail at this particular line of code?

[johannesvollmer]

Hi! Interesting. Can you provide the file? What error exactly to you encounter, a panic?

Mixing the channel types is tested in the library, so I'm pretty confident that mixing the channels is not the cause. I would like to have a look whether anything else might be the problem :)

[fursund]

https://drive.google.com/file/d/1dM0mpZXaMoAAZQCipFC0-7_hQ3t65wSM/view?usp=sharing

[johannesvollmer]

Thanks! I'll have a look :)

[fursund]

Thanks! It worked before miniz introduction in the lib.

[johannesvollmer]

You mean, before using the zune-inflate dependency for decompression (#183)? Or before using miniz-oxide (#162)?

[fursund]

Before miniz-oxide https://github.com/johannesvollmer/exrs/pull/162

[johannesvollmer]

Interesting. Good to know.

[johannesvollmer]

You think the expected byte size is calculated incorrectly? What error does it result in?

[fursund]

Error is: "thread 'main' panicked at 'called Result::unwrap() on an Err value: Invalid("compressed ZIP1 data (invalid: zlib-compressed data malformed)")'". Yeah my guess was that the expected byte size was wrong.

[johannesvollmer]

Thanks for sharing! I'll have a look as soon as I can :)

[fursund]

If I remove ".set_limit(expected_byte_size)" here: https://github.com/johannesvollmer/exrs/blob/66a247789004d974043300daf7bfc57c7d52a459/src/compression/zip.rs#L22 then it works

[johannesvollmer]

some findings:

• the error from zune-inflate is Output limit exceeded, set limit was 393,216 and output size is 392,539 note that output is actually smaller than the limit
• (as you said) removing set_limit on zlib no longer returns an error
• after decompressing with zune-inflate, the size is checked later, in decompress_image_section https://github.com/johannesvollmer/exrs/blob/66a247789004d974043300daf7bfc57c7d52a459/src/compression/mod.rs#L232 (note, this is the same expected_size variable computed earlier with pixel_section.size.area() * header.channels.bytes_per_pixel)
• the size check later succeeds
• zune-inflate would return the same number of bytes that the limit is set to

theory: the data is decompressed to the correct size, but zune-inflate reports an error when a limit is set, even though the limit is set to that exact size of the uncompressed data. the error message limit was 393,... and output size is 392,... shows that the data is smaller than the expected size, but an error is returned nevertheless.

[johannesvollmer]

here's the compressed data blob which results in the error: zlib-compressed-binary 393216 bytes.zip this is it, decompressed: zlib-compressed-binary 393216 bytes decompressed.zip, decompressed.len() = 393216

[johannesvollmer]

asked for help from our friends at zune-inflate

[johannesvollmer]

they fixed it incredibly fast, it's already online! now, be sure to run cargo update and then check if it works :)

[fursund]

great thanks!

[johannesvollmer]

alright, reopen this issue if the problem persists :)

[johannesvollmer]

this file must be added to the repository to detect this problem in the future

[johannesvollmer]

Please respond swiftly if you give the exrs project permission to use this file for testing purposes :) I will include it in the repository in that case

[fursund]

Yes you can use it for testing

[johannesvollmer]

awesome, thanks!