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Add note on Zstd compression levels about memory usage #120639

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Add note on Zstd compression levels about memory usage #120639

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2 changes: 2 additions & 0 deletions doc/classes/ProjectSettings.xml
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Expand Up @@ -511,6 +511,7 @@
</member>
<member name="compression/formats/zstd/compression_level" type="int" setter="" getter="" default="3">
The default compression level for Zstandard. Affects compressed scenes and resources. Higher levels result in smaller files at the cost of compression speed. Decompression speed is mostly unaffected by the compression level.
[b]Note:[/b] Levels above [code]19[/code] require significantly more memory during compression and decompression.

@Calinou Calinou Jun 26, 2026

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Is there a ballpark estimate of "significantly"? Is it something like 2x on average, or more like 5x?

@DeeJayLSP DeeJayLSP Jun 26, 2026 •
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This source claims level 19 has a window log size of 8MB. That size increases to 32MB, 64MB and 128MB in levels 20, 21 and 22, respectively.

Which means level 20 will allocate 4x more memory than level 19. Level 22 allocates 16x.

</member>
<member name="compression/formats/zstd/long_distance_matching" type="bool" setter="" getter="" default="false">
Enables [url=https://github.com/facebook/zstd/releases/tag/v1.3.2]long-distance matching[/url] in Zstandard.
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</member>
<member name="rendering/textures/basis_universal/zstd_supercompression_level" type="int" setter="" getter="" default="6">
Specify the compression level for Basis Universal Zstandard supercompression, ranging from [code]1[/code] to [code]22[/code].
[b]Note:[/b] Levels above [code]19[/code] require significantly more memory during compression and decompression.
</member>
<member name="rendering/textures/canvas_textures/default_texture_filter" type="int" setter="" getter="" default="1" keywords="nearest, linear">
The default texture filtering mode to use for [CanvasItem]'s built-in texture. In shaders, this texture is accessed as [code]TEXTURE[/code].
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