forked from unom/punktfunk
Completes the decoder trio. `D3d11vaDecoder::new` had the same cascading unwind as the VAAPI and Vulkan constructors — four branches each unref'ing the hwdevice by hand — and `d3d11va_decode_supported` opened a frames context it released on one exit path while relying on the null check for the other. Both are `AvBuffer` now. The one surviving `av_buffer_unref` in the file is deliberate: it runs before ownership is taken, on the `av_hwdevice_ctx_init` failure ahead of `from_raw`. The Windows gate then caught something worth keeping: `field hw_device is never read`, in all three decoders. It was true and it was new — the hand-written `Drop` used to be the field's only reader, so moving the unref into the type left a field that is *purely* an owner. The compiler cannot express that, so each one now carries a doc comment saying what it is and an explicit `#[allow(dead_code)]`. Deleting the field would free the device early; renaming it `_hw_device` would silence the lint by hiding what it holds. Neither is what we mean. Verified on BOTH platforms this time. Windows runner .133 (the toolchain env from the runner notes, plus `PF_FFVK_VULKAN_INCLUDE` for pf-ffvk): `cargo check -p pf-client-core --all-targets` at EXITCODE=0, clean of the dead-code warnings. Linux .21: `cargo check --workspace --all-targets` exit 0 / zero errors, pf-client-core 34 passed / 0 failed, pf-encode 33 passed / 0 failed.