Assorted optimizations for GStreamer's image-rs plugin#2907
Assorted optimizations for GStreamer's image-rs plugin#2907amyspark wants to merge 2 commits intoimage-rs:version-0.25from
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| /// Return the ICC profile's name as embedded in the image. | ||
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| /// For formats that don't store embedded profiles with separate names this function should always return `Ok(None)`. |
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Are there formats other than PNG which do store names for the embedded profiles?
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That's the only one. I introduced this API, however, because I didn't know how to downcast from impl ImageDecoder to PngDecoder (and so access a decoder specific API).
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We may need a novel mechanism for this. Downcast ties it to the png version which conflicts with the requirement of being able to bump it (through breaking changes). On the other hand a new API on the trait is also rather awkward. Maybe something similar to Error::provide would fit the bill in letting us translate types provided by version-encumbered crates to stable types defined in image directly (that we then only let include the 'stable' options / data from the formats). The converse holds for encoder, another unsatisfied user ask.
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You're trying to cast between a Box<dyn ImageDecoder> and a image::codecs::png::PngDecoder, right?
For that, I think we might just be able switch to a Box<dyn ImageDecoder + Any> or make Any a super-trait of ImageDecoder?
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Any does not really solve the problem. It only makes the dependency problem a runtime error but I'd consider that worse than a breaking change everytime we bump dependencies. There's no reasonable way to use Any::downcast right here for downstream—they'd have to add fallback cases for potentially unpublished versions of our dependencies preemptively to avoid functionality breaking and that just pollutes the dependency graph greatly.
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No, if I'm understanding correctly, the goal isn't to downcast to the decoder struct from the png crate but rather to cast to the PngDecoder struct in this crate
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Hi,
This is a MR to add a few things for feature parity in my GStreamer reader plugin:
iCCPchunk's profile nameread_imageBoth require upstream work, so marking as draft until those are landed: image-rs/image-png#679, mozilla/mp4parse-rust#446