refactor(host/W6.2): extract the video encode backends into the pf-encode crate

encode.rs + encode/* (NVENC, VAAPI, native AMF, AMF/QSV ffmpeg, direct-SDK
NVENC/CUDA, raw Vulkan-Video, PyroWave, openh264) move into crates/pf-encode
behind one Encoder trait + open_video selector (plan §W6). The crate speaks the
shared frame vocabulary (pf-frame: CapturedFrame/PixelFormat + the DXGI identity
D3d11Frame/make_device) and pf-zerocopy (CUDA context/buffers), and NEVER
pf-capture — the capture→encode edge is one-way (ZeroCopyPolicy, prior commit).

Dep moves: the heavy encoder deps (ffmpeg-next, the NVENC SDK, openh264,
pyrowave-sys) move from the host to pf-encode; the host's
nvenc/amf-qsv/vulkan-encode/pyrowave features now FORWARD to pf-encode/*. The
host keeps a mod-encode shim (pub use pf_encode) so every crate::encode::* path
(negotiator + GameStream/native/mgmt planes) is unchanged.

resolve_render_adapter_luid moves from the host's windows/win_adapter.rs into
pf-gpu (both pf-encode and pf-capture need it as a peer of GPU selection); its 5
call sites (encode amf/nvenc, capture idd_push/synthetic_nv12, vdisplay manager)
rewire to pf_gpu::resolve_render_adapter_luid and win_adapter.rs is deleted.
pf-frame's make_device gains a # Safety section (public-unsafe-fn lint, latent
since the pf-frame carve — a full-workspace -D warnings clippy catches it).

Verified: Linux clippy -D warnings (pf-encode + host nvenc,vulkan-encode,pyrowave
--all-targets) + 13/13 pf-encode + 299/299 host tests; Windows clippy -D warnings
(pf-encode nvenc,amf-qsv --all-targets + host nvenc,amf-qsv --all-targets)
Finished exit 0.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-07-17 10:42:51 +02:00
parent 1de83ba51d
commit 9a36ea2132
31 changed files with 339 additions and 224 deletions
+336
View File
@@ -0,0 +1,336 @@
//! Software H.264 encoder (openh264) — the GPU-less encode path for the Windows host (and a
//! fallback when NVENC is unavailable). Low-latency screen-content config: single-reference,
//! no B-frames (Baseline), bitrate rate-control, in-band SPS/PPS each IDR.
//! Synchronous: `submit` encodes immediately and stashes the AU for `poll` (no internal queue).
//!
//! The RGB→YUV conversion is OURS, BT.709 limited range: openh264 writes no colour description
//! into the VUI (unspecified), so decoders fall back to their default — BT.709 limited on every
//! punktfunk client — and the pixels must match that default. The crate's own `YUVBuffer`
//! converter is BT.601 (0.2578/0.5039/0.0977 + 16), which decoded-as-709 is a constant hue
//! error; that's why it is NOT used here.
// Every `unsafe` block in this file carries a `// SAFETY:` proof; enforce it (unsafe-proof program).
#![deny(clippy::undocumented_unsafe_blocks)]
use super::{EncodedFrame, Encoder};
use anyhow::{bail, ensure, Context, Result};
use openh264::encoder::{
BitRate, Complexity, Encoder as Oh264, EncoderConfig, FrameRate, FrameType, IntraFramePeriod,
Profile, RateControlMode, SpsPpsStrategy, UsageType,
};
use openh264::formats::YUVSlices;
use openh264::OpenH264API;
use pf_frame::{CapturedFrame, FramePayload, PixelFormat};
use std::collections::VecDeque;
pub struct OpenH264Encoder {
enc: Oh264,
width: u32,
height: u32,
fps: u32,
src_format: PixelFormat,
/// The converted I420 planes (our BT.709-limited CSC — see the module doc), reused across
/// frames: full-res luma + quarter-res Cb/Cr, tightly packed (stride = width, width/2).
y_plane: Vec<u8>,
u_plane: Vec<u8>,
v_plane: Vec<u8>,
frame_idx: i64,
force_kf: bool,
/// One AU per submit (no lookahead), handed back FIFO by `poll`. A queue, not an `Option`:
/// the session loop pipelines up to `capturer.pipeline_depth()` submits before polling, and a
/// single-slot pending would silently overwrite (lose) the older AUs — including the opening
/// IDR — and permanently skew the loop's FIFO pts pairing.
pending: VecDeque<EncodedFrame>,
}
// openh264's Encoder holds a raw C handle (not auto-Send); it lives on the single encode thread.
// SAFETY: `OpenH264Encoder` wraps `Oh264` (openh264's `Encoder`), which holds a raw C handle to the
// openh264 `ISVCEncoder` and is not auto-`Send`; the other fields (the plane `Vec`s, scalars,
// `Option<EncodedFrame>`) are plain owned data. The session creates the encoder, calls
// `submit`/`poll`/`flush`, and drops it all on one dedicated encode thread, never sharing it by
// reference across threads, so the C handle is only ever touched from a single thread. Moving the
// whole value to that thread is therefore sound — there is no concurrent access to the handle.
unsafe impl Send for OpenH264Encoder {}
impl OpenH264Encoder {
pub fn open(
format: PixelFormat,
width: u32,
height: u32,
fps: u32,
bitrate_bps: u64,
) -> Result<Self> {
// validate_dimensions() ran in open_video: even, non-zero, <= 4096.
let bps: u32 = bitrate_bps.try_into().unwrap_or(u32::MAX);
let cfg = EncoderConfig::new()
.usage_type(UsageType::ScreenContentRealTime)
.max_frame_rate(FrameRate::from_hz(fps.max(1) as f32))
.rate_control_mode(RateControlMode::Bitrate)
.bitrate(BitRate::from_bps(bps))
.skip_frames(false)
.intra_frame_period(IntraFramePeriod::from_num_frames(intra_period_frames(fps)))
.sps_pps_strategy(SpsPpsStrategy::ConstantId) // SPS/PPS in-band on every IDR
.num_threads(num_threads())
.scene_change_detect(false) // no surprise IDRs (bitrate spikes / freeze)
.adaptive_quantization(true)
.complexity(Complexity::Low) // latency over BD-rate
.profile(Profile::Baseline); // no B-frames; the VUI carries no colour description
let api = OpenH264API::from_source(); // statically-bundled build (default `source` feature)
let enc = Oh264::with_api_config(api, cfg).context("openh264 Encoder::with_api_config")?;
let (w, h) = (width as usize, height as usize);
tracing::info!(
"openh264 software encoder: {width}x{height}@{fps} {} Mbps (Baseline, screen-content)",
bps / 1_000_000
);
Ok(Self {
enc,
width,
height,
fps,
src_format: format,
y_plane: vec![0; w * h],
u_plane: vec![0; (w / 2) * (h / 2)],
v_plane: vec![0; (w / 2) * (h / 2)],
frame_idx: 0,
force_kf: false,
pending: VecDeque::new(),
})
}
/// Convert one packed full-range RGB frame into the I420 planes, BT.709 limited range.
/// `bpp` is the source pixel stride; `ri`/`gi`/`bi` the channel byte offsets within a pixel.
/// Luma per pixel; Cb/Cr from the 2×2 block's averaged RGB (the same box filter the crate's
/// converter used, so only the matrix changed).
fn convert_bt709(&mut self, src: &[u8], bpp: usize, ri: usize, gi: usize, bi: usize) {
let w = self.width as usize;
let h = self.height as usize;
let cw = w / 2;
for by in 0..h / 2 {
for bx in 0..cw {
let mut sum = (0f32, 0f32, 0f32);
for (dy, dx) in [(0, 0), (0, 1), (1, 0), (1, 1)] {
let (px, py) = (bx * 2 + dx, by * 2 + dy);
let s = &src[(py * w + px) * bpp..];
let (r, g, b) = (f32::from(s[ri]), f32::from(s[gi]), f32::from(s[bi]));
self.y_plane[py * w + px] = luma709(r, g, b);
sum = (sum.0 + r, sum.1 + g, sum.2 + b);
}
let (cb, cr) = chroma709(sum.0 / 4.0, sum.1 / 4.0, sum.2 / 4.0);
self.u_plane[by * cw + bx] = cb;
self.v_plane[by * cw + bx] = cr;
}
}
}
}
/// BT.709 luma coefficients (Kg = 1 Kr Kb).
const KR: f32 = 0.2126;
const KB: f32 = 0.0722;
const KG: f32 = 1.0 - KR - KB;
/// One full-range RGB pixel (0..=255 channels) → the BT.709 limited-range 8-bit luma code
/// (16..=235). Kept in lockstep with the client-side inverse (`pf-client-core::video::csc_rows`).
fn luma709(r: f32, g: f32, b: f32) -> u8 {
let y = KR * r + KG * g + KB * b; // full-scale luma, 0..=255
(16.0 + y * (219.0 / 255.0) + 0.5) as u8 // `as` saturates — no manual clamp needed
}
/// (Averaged) full-range RGB → the BT.709 limited-range Cb/Cr codes (16..=240, neutral 128).
fn chroma709(r: f32, g: f32, b: f32) -> (u8, u8) {
let y = KR * r + KG * g + KB * b;
let cb = 128.0 + (b - y) * (224.0 / 255.0) / (2.0 * (1.0 - KB));
let cr = 128.0 + (r - y) * (224.0 / 255.0) / (2.0 * (1.0 - KR));
((cb + 0.5) as u8, (cr + 0.5) as u8)
}
impl Encoder for OpenH264Encoder {
fn submit(&mut self, captured: &CapturedFrame) -> Result<()> {
ensure!(
captured.width == self.width && captured.height == self.height,
"captured {}x{} != encoder {}x{}",
captured.width,
captured.height,
self.width,
self.height
);
ensure!(
captured.format == self.src_format,
"captured format {:?} != encoder source {:?}",
captured.format,
self.src_format
);
// Refutable once the capture backend adds `FramePayload::D3d11`; today `Cpu` is the only
// non-Linux variant, so the pattern is (temporarily) irrefutable.
#[allow(irrefutable_let_patterns)]
let FramePayload::Cpu(bytes) = &captured.payload
else {
bail!("openh264 backend requires a CPU frame payload");
};
let w = self.width as usize;
let h = self.height as usize;
ensure!(
bytes.len() >= w * h * self.src_format.bytes_per_pixel(),
"captured buffer {} bytes too small for {w}x{h} {:?}",
bytes.len(),
self.src_format
);
// Source pixel stride + R/G/B byte offsets within a pixel — one converter for every
// packed-RGB layout the capturers emit (no BGRA normalization pass needed).
let (bpp, ri, gi, bi) = match self.src_format {
PixelFormat::Rgb => (3, 0, 1, 2),
PixelFormat::Bgr => (3, 2, 1, 0),
PixelFormat::Rgba | PixelFormat::Rgbx => (4, 0, 1, 2),
PixelFormat::Bgra | PixelFormat::Bgrx => (4, 2, 1, 0),
// 10-bit HDR comes only from the GPU NVENC path; the software 8-bit H.264 encoder
// can't represent it (and never receives it — the capturer pairs Rgb10a2 with NVENC).
PixelFormat::Rgb10a2 => {
anyhow::bail!("software H.264 encoder cannot encode 10-bit HDR (Rgb10a2)")
}
// NV12/P010 are GPU-resident video-processor outputs for the NVENC path; the software
// encoder never receives them (it only gets CPU RGB frames).
PixelFormat::Nv12 | PixelFormat::P010 | PixelFormat::Yuv444 => {
anyhow::bail!(
"software encoder cannot encode YUV GPU frames (NV12/P010/YUV444 → NVENC only)"
)
}
};
self.convert_bt709(bytes, bpp, ri, gi, bi);
if self.force_kf {
self.enc.force_intra_frame();
self.force_kf = false;
}
let slices = YUVSlices::new(
(&self.y_plane, &self.u_plane, &self.v_plane),
(w, h),
(w, w / 2, w / 2),
);
let bs = self.enc.encode(&slices).context("openh264 encode")?;
let mut data = Vec::new();
bs.write_vec(&mut data); // AnnexB start codes; SPS/PPS prepended on IDR
if !data.is_empty() {
let keyframe = matches!(bs.frame_type(), FrameType::IDR | FrameType::I);
let pts_ns = self.frame_idx as u64 * 1_000_000_000 / self.fps.max(1) as u64;
self.pending.push_back(EncodedFrame {
data,
pts_ns,
keyframe,
recovery_anchor: false,
chunk_aligned: false,
});
}
self.frame_idx += 1;
Ok(())
}
fn request_keyframe(&mut self) {
self.force_kf = true;
}
fn poll(&mut self) -> Result<Option<EncodedFrame>> {
Ok(self.pending.pop_front())
}
fn flush(&mut self) -> Result<()> {
Ok(()) // synchronous: nothing buffered
}
}
/// Approximate infinite-GOP: insert IDRs rarely (recovery is via `request_keyframe`/RFI). Env
/// `PUNKTFUNK_OH264_GOP` overrides (0 = encoder-auto).
fn intra_period_frames(fps: u32) -> u32 {
if let Ok(v) = std::env::var("PUNKTFUNK_OH264_GOP") {
if let Ok(n) = v.trim().parse::<u32>() {
return n;
}
}
fps.max(1).saturating_mul(600) // ~10 min between automatic IDRs
}
/// Encode threads. Env `PUNKTFUNK_OH264_THREADS` overrides; default 2 (latency over throughput).
fn num_threads() -> u16 {
std::env::var("PUNKTFUNK_OH264_THREADS")
.ok()
.and_then(|v| v.trim().parse::<u16>().ok())
.unwrap_or(2)
}
#[cfg(test)]
mod tests {
use super::*;
use pf_frame::{CapturedFrame, FramePayload, PixelFormat};
/// The BT.709 limited-range anchor points: reference white → (235,128,128), black →
/// (16,128,128), pure red's Cr must hit the positive extreme 240 (it does exactly:
/// 255(1Kr)·(224/255)/(2(1Kr)) = 112). ±1 code for float rounding.
#[test]
fn bt709_conversion_anchor_points() {
assert_eq!(luma709(255.0, 255.0, 255.0), 235);
assert_eq!(luma709(0.0, 0.0, 0.0), 16);
assert_eq!(chroma709(255.0, 255.0, 255.0), (128, 128));
assert_eq!(chroma709(0.0, 0.0, 0.0), (128, 128));
let (cb, cr) = chroma709(255.0, 0.0, 0.0);
assert_eq!(cr, 240, "pure red must reach the Cr extreme");
assert!((101..=103).contains(&cb), "red Cb ~102, got {cb}");
let (cb, _) = chroma709(0.0, 0.0, 255.0);
assert_eq!(cb, 240, "pure blue must reach the Cb extreme");
}
/// The 601-vs-709 luma split on pure green (Kg 0.587 vs 0.7152) — guards against anyone
/// "simplifying" the coefficients back to the crate's BT.601 converter (the hue-shift bug
/// this module's own conversion exists to prevent).
#[test]
fn bt709_is_not_bt601() {
// BT.601 green luma: 16 + 219·0.587 = 144.5; BT.709: 16 + 219·0.7152 = 172.6.
let y = luma709(0.0, 255.0, 0.0);
assert!((172..=174).contains(&y), "709 green luma ~173, got {y}");
}
/// A flat gray frame converts to neutral chroma and mid luma across every plane byte
/// (exercises the block loop + plane sizing, not just the per-pixel math).
#[test]
fn converts_flat_gray_to_neutral_planes() {
let (w, h) = (16u32, 8u32);
let mut enc =
OpenH264Encoder::open(PixelFormat::Bgrx, w, h, 60, 1_000_000).expect("open openh264");
let bytes = vec![0x80u8; (w * h * 4) as usize];
enc.convert_bt709(&bytes, 4, 2, 1, 0);
// 16 + 128·(219/255) = 125.9 → 126.
assert!(
enc.y_plane.iter().all(|&y| y == 126),
"{:?}",
&enc.y_plane[..4]
);
assert!(enc.u_plane.iter().all(|&u| u == 128));
assert!(enc.v_plane.iter().all(|&v| v == 128));
}
#[test]
fn encodes_synthetic_frame_to_annexb_idr() {
let (w, h, fps) = (1280u32, 720u32, 60u32);
let mut enc =
OpenH264Encoder::open(PixelFormat::Bgrx, w, h, fps, 8_000_000).expect("open openh264");
// A flat gray BGRx frame.
let frame = CapturedFrame {
width: w,
height: h,
pts_ns: 0,
format: PixelFormat::Bgrx,
payload: FramePayload::Cpu(vec![0x80u8; (w * h * 4) as usize]),
cursor: None,
};
enc.submit(&frame).expect("submit");
let au = enc.poll().expect("poll").expect("an AU");
assert!(au.keyframe, "first frame must be an IDR");
// AnnexB start code + an SPS NAL (type 7) somewhere in the first frame.
assert!(
au.data.starts_with(&[0, 0, 0, 1]) || au.data.starts_with(&[0, 0, 1]),
"expected AnnexB start code"
);
let has_sps = au
.data
.windows(5)
.any(|w| w[0] == 0 && w[1] == 0 && w[2] == 0 && w[3] == 1 && (w[4] & 0x1f) == 7);
assert!(has_sps, "IDR must carry an SPS NAL (type 7)");
}
}