aleleba/deckcraft
1
0
Fork 0
mirror of https://github.com/storytold/deckcraft.git synced 2026-10-25 19:17:06 -06:00
Code Issues Packages Projects Releases Wiki Activity

refactor(hevc): split derive_merge into spatial, temporal, combined and zero stages (S3776) (#1401)

Browse Source
This commit is contained in:
Dylan M. Taylor
2026-10-25 20:55:39 -04:00
committed by GitHub
parent 430d0a91c0
commit 16fe4ebc65
1 changed files with 53 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files
crates/hevc/src/mvpred.rs
+53 -32
View File
@@ -74,16 +74,39 @@ impl<'a> SliceDecoder<'a> {
/// Merge mode motion (8.5.3.2.2).
pub fn derive_merge(&self, g: PbGeom, part: PartMode, merge_idx: usize) -> MvField {
let PbGeom { xc, yc, ncb, xp: xp0, yp: yp0, w: w0, h: h0, part_idx: part_idx0 } = g;
let (w0, h0) = (g.w, g.h);
// With a parallel merge level above 4x4, an 8x8 coding block shares one candidate set.
let g = if self.pps.log2_parallel_merge_level > 2 && g.ncb == 8 {
PbGeom { xp: g.xc, yp: g.yc, w: g.ncb, h: g.ncb, part_idx: 0, ..g }
} else {
g
};
let max = self.sh.max_num_merge_cand as usize;
let (list, n) = self.spatial_merge_candidates(&g, part);
if merge_idx < n {
return self.finish_merge(list[merge_idx], w0, h0);
}
let mut cands: Vec<MvField> = list[..n].to_vec();
cands.extend(self.temporal_merge_candidate(g.xp, g.yp, g.w, g.h));
if merge_idx < cands.len() {
return self.finish_merge(cands[merge_idx], w0, h0);
}
self.combined_merge_candidates(&mut cands, max);
if merge_idx < cands.len() {
return self.finish_merge(cands[merge_idx], w0, h0);
}
self.zero_merge_candidates(&mut cands, merge_idx);
self.finish_merge(cands[merge_idx], w0, h0)
}
/// The spatial candidates A1, B1, B0, A0 and B2 (8.5.3.2.3): the candidates, and how many.
fn spatial_merge_candidates(&self, g: &PbGeom, part: PartMode) -> ([MvField; 5], usize) {
let PbGeom { xp, yp, w, h, part_idx, .. } = *g;
let pml = self.pps.log2_parallel_merge_level;
let (xp, yp, w, h, part_idx) = if pml > 2 && ncb == 8 { (xc, yc, ncb, ncb, 0) } else { (xp0, yp0, w0, h0, part_idx0) };
let g = PbGeom { xc, yc, ncb, xp, yp, w, h, part_idx };
let same_mer = |xn: i32, yn: i32| (xp >> pml) == (xn >> pml) && (yp >> pml) == (yn >> pml);
let avail = |xn: i32, yn: i32| self.pb_avail(&g, xn, yn) && !same_mer(xn, yn);
let avail = |xn: i32, yn: i32| self.pb_avail(g, xn, yn) && !same_mer(xn, yn);
let mut list: [MvField; 5] = [MvField::default(); 5];
let mut n = 0;
let max = self.sh.max_num_merge_cand as usize;
// spatial candidates (8.5.3.2.3)
let pa1 = (xp - 1, yp + h - 1);
let av_a1 = avail(pa1.0, pa1.1) && !(matches!(part, PartMode::PNx2N | PartMode::PnLx2N | PartMode::PnRx2N) && part_idx == 1);
let m_a1 = if av_a1 { self.mv_at(pa1.0, pa1.1) } else { MvField::default() };
@@ -130,10 +153,11 @@ impl<'a> SliceDecoder<'a> {
list[n] = self.mv_at(pb2.0, pb2.1);
n += 1;
}
if merge_idx < n {
return self.finish_merge(list[merge_idx], w0, h0);
}
// temporal candidate
(list, n)
}
/// The temporal candidate (8.5.3.2.8): list 0 from the collocated picture, and list 1 for B slices.
fn temporal_merge_candidate(&self, xp: i32, yp: i32, w: i32, h: i32) -> Option<MvField> {
let mut col = MvField::default();
let mut col_avail = false;
if let Some(mv) = self.temporal(xp, yp, w, h, 0, 0) {
@@ -148,30 +172,28 @@ impl<'a> SliceDecoder<'a> {
col.ref_idx[1] = 0;
col_avail = true;
}
let mut cands: Vec<MvField> = list[..n].to_vec();
if col_avail {
cands.push(col);
}
if merge_idx < cands.len() {
return self.finish_merge(cands[merge_idx], w0, h0);
}
// combined bi-predictive candidates (8.5.3.2.4)
col_avail.then_some(col)
}
/// Combined bi-predictive candidates (8.5.3.2.4) from pairs of the original candidates.
fn combined_merge_candidates(&self, cands: &mut Vec<MvField>, max: usize) {
let num_orig = cands.len();
if self.sh.is_b() && num_orig > 1 && num_orig < max {
let mut comb = 0;
while comb < num_orig * (num_orig - 1) && cands.len() < max {
let (i0, i1) = COMB[comb];
let (c0, c1) = (cands[i0], cands[i1]);
if c0.pred(0) && c1.pred(1) && (self.ref_pic(0, c0.ref_idx[0]).poc != self.ref_pic(1, c1.ref_idx[1]).poc || c0.mv[0] != c1.mv[1]) {
cands.push(MvField { mv: [c0.mv[0], c1.mv[1]], ref_idx: [c0.ref_idx[0], c1.ref_idx[1]] });
}
comb += 1;
if !(self.sh.is_b() && num_orig > 1 && num_orig < max) {
return;
}
let mut comb = 0;
while comb < num_orig * (num_orig - 1) && cands.len() < max {
let (i0, i1) = COMB[comb];
let (c0, c1) = (cands[i0], cands[i1]);
if c0.pred(0) && c1.pred(1) && (self.ref_pic(0, c0.ref_idx[0]).poc != self.ref_pic(1, c1.ref_idx[1]).poc || c0.mv[0] != c1.mv[1]) {
cands.push(MvField { mv: [c0.mv[0], c1.mv[1]], ref_idx: [c0.ref_idx[0], c1.ref_idx[1]] });
}
comb += 1;
}
if merge_idx < cands.len() {
return self.finish_merge(cands[merge_idx], w0, h0);
}
// zero candidates (8.5.3.2.5)
}
/// Zero candidates (8.5.3.2.5) up to and including `merge_idx`.
fn zero_merge_candidates(&self, cands: &mut Vec<MvField>, merge_idx: usize) {
let num_ref = if self.sh.is_b() { self.sh.num_ref_idx[0].min(self.sh.num_ref_idx[1]) } else { self.sh.num_ref_idx[0] } as usize;
let mut zero_idx = 0;
while cands.len() <= merge_idx {
@@ -179,7 +201,6 @@ impl<'a> SliceDecoder<'a> {
cands.push(MvField { mv: [[0; 2]; 2], ref_idx: [r, if self.sh.is_b() { r } else { -1 }] });
zero_idx += 1;
}
self.finish_merge(cands[merge_idx], w0, h0)
}
fn finish_merge(&self, mut f: MvField, w: i32, h: i32) -> MvField {