The strict-clippy split of inverse_dct (#2496) passes n at run time; inlining keeps
inverse_dct_n's compile-time sizes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The inverse transform computed its bit-reversal permutations and loop
bounds at run time and went through one generic path for every size.
inverse_dct, the ADST permutations and inverse_2d are now const generic
over the size and inlined, so the permutations fold at compile time.
forward_2d zeroed a 4 KiB tmp buffer on every call, even for 4x4. It now
dispatches to a fixed-size version for 4, 8 and 16 (tmp is exactly n*n
floats); 32 keeps the run-time version, which measured faster than a
const 32 variant. The float operation order is unchanged.
Output is bit-identical.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>
Replaces the encoder's 11 expect()/unreachable!() calls on internal invariants with handling
that can't panic: the rate-control state is passed in rather than re-borrowed, inter decisions
without a reference frame fall back to intra, per-plane results are bound directly, and the
writer's impossible branches become debug_asserts. Denies the panic lints in the crate.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
