Windows: NVENC H.265 (HEVC) Main hardware encoding for Export

One NVENC session, ring and NV12 path now serve H.264 and HEVC (Codec enum,
Profile::HevcMain). HEVC Main 8-bit 4:2:0 SDR BT.709, MP4/MOV hvc1, parameter
sets only in an hvcC built from the SPS the encoder wrote. The H.265 format is
available through a cached NVENC probe; choosing it is the opt-in, declines are
counted errors. ABI asserts regenerated from nvEncodeAPI.h 12.1 (no drift) and
extended for HEVC; tests, docs and roadmap updated.

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>

ROADMAP.md

@@ -35,8 +35,8 @@ before choosing work.
 | **Feature breadth** (menus, commands, panels) | ~86–95% | **~85%** | Menu diff against Premiere 26.5; effect, transition and audio-effect catalogues complete by test. The long tail is mostly there. |
 | **Correctness in depth** | not tracked | **~60–70%** | A first-time contributor found four real bugs in core paths within hours (#5–#8: AIFF import failed, Slide left linked audio behind, transitions didn't follow ripple trims, export ignored start/end times). User reports: Color Matte always grey with no picker (#29); ALSA audio error on Linux (#23). Settings are "most wired", not all. |
 | **Codecs and media** | ~90% | **~75%** | Our decoders are bit-exact on conformance streams. Real camera and phone media (variable frame rate, damaged files, unusual containers) is far less tested. No camera RAW (RED, BRAW, ARRIRAW), no E-AC-3. |
-| **Export** | ~92% | **~70%** | Delivery: H.264 only (ProRes, DNxHR and image sequences cover mastering). No HEVC or AV1 export. AAF and OMF have never been validated in Avid Media Composer or Pro Tools. Export renders and encodes on the CPU only. |
-| **Performance and hardware** | ~62% | **~35–40%** | Premiere runs effects, decoding and encoding on the GPU and the hardware media engines. Here, hardware decode works on macOS (VideoToolbox, #33; active in the desktop app only since #41, so releases up to 0.2.1 decoded in software) and Windows (Media Foundation / Direct3D 11 DXVA, H.264, HEVC Main / Main 10, VP9 and AV1 4:2:0 8/10-bit, #30). The GPU does compositing, blend modes (#32) and 31 common effects (GPU2): colour adjustments, crop/flip/transform, blurs, sharpen. Lumetri, keys, masks, the remaining effects and export rendering are CPU; H.264 encoding can use VideoToolbox on macOS (opt-in per export, no B-frames) and NVENC on Windows with an NVIDIA GPU (opt-in per export), and H.265 (HEVC) export exists there only, through the same hardware encoder. Linux has no hardware path. 8K isn't real-time (AV1 is on Windows with a hardware decoder). The effect list shows Premiere's "GPU accelerated" badge, but only 31 effect ids run on the GPU here; the rest, Lumetri included, run on the CPU. |
+| **Export** | ~92% | **~70%** | Delivery: H.264, plus H.265 (8-bit Main, SDR) through a hardware encoder only (NVENC on Windows, VideoToolbox on macOS); ProRes, DNxHR and image sequences cover mastering. No AV1 export, no HDR or 10-bit HEVC. AAF and OMF have never been validated in Avid Media Composer or Pro Tools. Export renders and encodes on the CPU only. |
+| **Performance and hardware** | ~62% | **~35–40%** | Premiere runs effects, decoding and encoding on the GPU and the hardware media engines. Here, hardware decode works on macOS (VideoToolbox, #33; active in the desktop app only since #41, so releases up to 0.2.1 decoded in software) and Windows (Media Foundation / Direct3D 11 DXVA, H.264, HEVC Main / Main 10, VP9 and AV1 4:2:0 8/10-bit, #30). The GPU does compositing, blend modes (#32) and 31 common effects (GPU2): colour adjustments, crop/flip/transform, blurs, sharpen. Lumetri, keys, masks, the remaining effects and export rendering are CPU; H.264 encoding can use VideoToolbox on macOS (opt-in per export, no B-frames) and NVENC on Windows with an NVIDIA GPU (opt-in per export), and H.265 (HEVC) export exists there only, through the same hardware encoders (macOS and Windows). Linux has no hardware path. 8K isn't real-time (AV1 is on Windows with a hardware decoder). The effect list shows Premiere's "GPU accelerated" badge, but only 31 effect ids run on the GPU here; the rest, Lumetri included, run on the CPU. |
 | **Stability** | not tracked | **improving, unproven** | The never-crash pass (no panics in product code, last-resort guards) landed on 2026-10-04. There's no field record from real users' projects yet. |
 | **Plugins and pro ecosystem** | not tracked | **~0–10%** | No audio plugin hosting (VST3 / Audio Units) and no third-party video effects (OpenFX). For many professional editors this alone rules FilmCraft out. Team Projects and Productions are out of scope by design. |
 | **AI features** | partial | **~25–35%** | Speech to text exists but is off in default builds (the `whisper` feature). Enhance Speech is a DSP chain, not a model. Auto Reframe is approximate. No Generative Extend, and no media-intelligence search or auto colour. |
@@ -51,7 +51,7 @@ In priority order. Agents should prefer this work over adding more checklist ite
    - hardware decode on Linux (VA-API);
    - zero-copy decoded frames into wgpu;
    - the remaining effects on the GPU: Lumetri, keys, Vignette, Video Limiter, masks (31 common effects are done);
-   - GPU export, then hardware encode: H.264 and H.265 on macOS are in (H.264 opt-in; H.265 has no other encoder), H.264 on NVENC (Windows, opt-in); HEVC on Windows and Linux remain.
+   - GPU export, then hardware encode: H.264 and H.265 on macOS are in (H.264 opt-in; H.265 has no other encoder), H.264 and H.265 (Main, 8-bit) on NVENC (Windows); Main 10 / HDR HEVC, Linux and other Windows vendors remain.
 2. **A measured parity number.** Add `cargo xtask parity`, run in CI. It should cover menus,
    commands, effects, transitions, panels, preferences and formats against the Premiere snapshot in
    `plan/premiere/`. It should report presence and fidelity separately (exact, approximate, stub).
@@ -154,11 +154,13 @@ Status: ✅ done · 🟡 in progress · ⬜ not started. Estimates are remaining
 
 ## Running now
 
-- **Hardware acceleration (#30):** landed: blend modes on the GPU (#32); VideoToolbox hardware decode + the `platform` FFI crate (#33); 31 common effects on the GPU (GPU2). Windows: Media Foundation / Direct3D 11 H.264 + HEVC decode (HW2) and VP9 + AV1 (HW3), NVENC H.264 export (HW4, opt-in). Next: VA-API (Linux) decode, zero-copy upload, Lumetri on the GPU.
+- **Hardware acceleration (#30):** landed: blend modes on the GPU (#32); VideoToolbox hardware decode + the `platform` FFI crate (#33); 31 common effects on the GPU (GPU2). Windows: Media Foundation / Direct3D 11 H.264 + HEVC decode (HW2) and VP9 + AV1 (HW3), NVENC H.264 export (HW4, opt-in) and H.265 export. Next: VA-API (Linux) decode, zero-copy upload, Lumetri on the GPU.
 - **Next:** [Where we are lacking](#where-we-are-lacking) items 1–5. GPU export waits for the export-crate work (#19 and the never-crash follow-up) to land.
 
 ## Log
 
+- **2026-10-08:** H.265 (HEVC Main, 8-bit 4:2:0, SDR) export on Windows through NVENC (#30): the NVENC session, ring and NV12 path of the H.264 encoder now serve both codecs (the H.264 export is byte-for-byte unchanged); the format is available where the GPU has an HEVC encoder, choosing it is the opt-in, and `hvcC` is built from the SPS the encoder wrote. ffprobe reads `hevc` / `Main` / `hvc1` / `yuv420p` / BT.709; our own HEVC decoder decodes it at 48.9 dB luma PSNR (RTX 5060). Main 10 and HDR remain.
+
 - **2026-10-06:** 21 community PRs landed (#19, #28, #38, #39, #41–#60). Highlights: hardware decoding is now actually on in the desktop app (#41: `register()` sat inside a `log::info!` that never ran, so #33's VideoToolbox path only worked in the CLI and benchmarks); decode memory on long timelines cut sharply (frame pool, shared GOP-cache budget, positional file reads); exports are byte-identical across machines (#19); crash fix for odd track names over MCP (#44); ripple trim, ripple delete and speed changes move split-edit clips once (#56–#58); Japanese interface using an installed system font (#38; no fonts bundled); MCP annotations, resources, export progress and cancellation (#28).
 
 - **2026-10-05:** honest assessment added (checklist ~87% vs ready for real work ~50–60%). Hardware acceleration started (#30): blend modes on the GPU (#32); VideoToolbox decode + `platform` crate, the one crate allowed `unsafe` (#33). Community fixes landed: AIFF import, export start/end ranges, transitions following ripple trims, Slide moving linked audio (#5–#8).