Rav1dFrameContext_lf::p: Make into offsets

memorysafety · Mar 12, 2024 · f0bee52 · f0bee52
1 parent f65d252
commit f0bee52
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Showing 3 changed files with 40 additions and 19 deletions.
diff --git a/src/decode.rs b/src/decode.rs
@@ -4603,13 +4603,12 @@ pub(crate) unsafe fn rav1d_decode_frame_init(
         }
     }
 
-    // Init loopfilter pointers. Increasing NULL pointers is technically UB,
-    // so just point the chroma pointers in 4:0:0 to the luma plane here
-    // to avoid having additional in-loop branches in various places.
-    // We never dereference those pointers, so it doesn't really matter
-    // what they point at, as long as the pointers are valid.
+    // Init loopfilter offsets. Point the chroma offsets in 4:0:0 to the luma
+    // plane here to avoid having additional in-loop branches in various places.
+    // We never use those values, so it doesn't really matter what they point
+    // at, as long as the offsets are valid.
     let has_chroma = (f.cur.p.layout != Rav1dPixelLayout::I400) as usize;
-    f.lf.p = array::from_fn(|i| f.cur.data.data[has_chroma * i].cast());
+    f.lf.p = array::from_fn(|i| has_chroma * i);
     f.lf.sr_p = array::from_fn(|i| f.sr_cur.p.data.data[has_chroma * i].cast());
 
     Ok(())

diff --git a/src/internal.rs b/src/internal.rs
@@ -468,7 +468,7 @@ pub struct Rav1dFrameContext_lf {
 
     // in-loop filter per-frame state keeping
     pub start_of_tile_row: Vec<u8>,
-    pub p: [*mut DynPixel; 3],
+    pub p: [usize; 3], // Offsets into `f.cur.data.data`.
     pub sr_p: [*mut DynPixel; 3],
     pub restore_planes: c_int, // enum LrRestorePlanes
 }

diff --git a/src/recon.rs b/src/recon.rs
@@ -4510,15 +4510,21 @@ pub(crate) unsafe fn rav1d_filter_sbrow_deblock_cols<BD: BitDepth>(
 
         let p: [&mut [BD::Pixel]; 3] = [
             slice::from_raw_parts_mut(
-                (f.lf.p[0] as *mut BD::Pixel).offset(cmp::min(y_span, 0)),
+                f.cur.data.data[f.lf.p[0]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(y_span, 0)),
                 y_span.unsigned_abs() + y_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
             slice::from_raw_parts_mut(
-                (f.lf.p[1] as *mut BD::Pixel).offset(cmp::min(uv_span, 0)),
+                f.cur.data.data[f.lf.p[1]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(uv_span, 0)),
                 uv_span.unsigned_abs() + uv_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
             slice::from_raw_parts_mut(
-                (f.lf.p[2] as *mut BD::Pixel).offset(cmp::min(uv_span, 0)),
+                f.cur.data.data[f.lf.p[2]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(uv_span, 0)),
                 uv_span.unsigned_abs() + uv_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
         ];
@@ -4562,15 +4568,21 @@ pub(crate) unsafe fn rav1d_filter_sbrow_deblock_rows<BD: BitDepth>(
 
         let p: [&mut [BD::Pixel]; 3] = [
             slice::from_raw_parts_mut(
-                (f.lf.p[0] as *mut BD::Pixel).offset(cmp::min(y_span, 0)),
+                f.cur.data.data[f.lf.p[0]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(y_span, 0)),
                 y_span.unsigned_abs() + y_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
             slice::from_raw_parts_mut(
-                (f.lf.p[1] as *mut BD::Pixel).offset(cmp::min(uv_span, 0)),
+                f.cur.data.data[f.lf.p[1]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(uv_span, 0)),
                 uv_span.unsigned_abs() + uv_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
             slice::from_raw_parts_mut(
-                (f.lf.p[2] as *mut BD::Pixel).offset(cmp::min(uv_span, 0)),
+                f.cur.data.data[f.lf.p[2]]
+                    .cast::<BD::Pixel>()
+                    .offset(cmp::min(uv_span, 0)),
                 uv_span.unsigned_abs() + uv_width as usize + RAV1D_PICTURE_ALIGNMENT,
             ),
         ];
@@ -4608,10 +4620,14 @@ pub(crate) unsafe fn rav1d_filter_sbrow_cdef<BD: BitDepth>(
     let y = sby * sbsz * 4;
     let ss_ver = (f.cur.p.layout as c_uint == Rav1dPixelLayout::I420 as c_int as c_uint) as c_int;
     let p: [*mut BD::Pixel; 3] = [
-        (f.lf.p[0] as *mut BD::Pixel).offset((y as isize * BD::pxstride(f.cur.stride[0])) as isize),
-        (f.lf.p[1] as *mut BD::Pixel)
+        f.cur.data.data[f.lf.p[0]]
+            .cast::<BD::Pixel>()
+            .offset((y as isize * BD::pxstride(f.cur.stride[0])) as isize),
+        f.cur.data.data[f.lf.p[1]]
+            .cast::<BD::Pixel>()
             .offset((y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver) as isize),
-        (f.lf.p[2] as *mut BD::Pixel)
+        f.cur.data.data[f.lf.p[2]]
+            .cast::<BD::Pixel>()
             .offset((y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver) as isize),
     ];
     let seq_hdr = &***f.seq_hdr.as_ref().unwrap();
@@ -4644,9 +4660,15 @@ pub(crate) unsafe fn rav1d_filter_sbrow_resize<BD: BitDepth>(
     let y = sby * sbsz * 4;
     let ss_ver = (f.cur.p.layout as c_uint == Rav1dPixelLayout::I420 as c_int as c_uint) as c_int;
     let p: [*const BD::Pixel; 3] = [
-        (f.lf.p[0] as *mut BD::Pixel).offset(y as isize * BD::pxstride(f.cur.stride[0])),
-        (f.lf.p[1] as *mut BD::Pixel).offset(y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver),
-        (f.lf.p[2] as *mut BD::Pixel).offset(y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver),
+        f.cur.data.data[f.lf.p[0]]
+            .cast::<BD::Pixel>()
+            .offset(y as isize * BD::pxstride(f.cur.stride[0])),
+        f.cur.data.data[f.lf.p[1]]
+            .cast::<BD::Pixel>()
+            .offset(y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver),
+        f.cur.data.data[f.lf.p[2]]
+            .cast::<BD::Pixel>()
+            .offset(y as isize * BD::pxstride(f.cur.stride[1]) >> ss_ver),
     ];
     let sr_p: [*mut BD::Pixel; 3] = [
         (f.lf.sr_p[0] as *mut BD::Pixel)