The assert attempted to guard against file formats declaring themselves as "requiring a float buffer" but outputing to a "byte buffer". However, DPX seems to permit this and the code seems to support it correctly. The assert was originally added in 2022 by5baa3ecda6. Subsequently the test which exposed the problem was added in 2023 by7699c7407d. But the issue at hand has existed since DPX was added; it's the only format with this combination of capabilities. Pull Request: https://projects.blender.org/blender/blender/pulls/117914