From a49570e45ba9d8f1874c7fb8a2f5f1ed44ccb443 Mon Sep 17 00:00:00 2001
From: MarekSpodBiedry <73122968+MarekSpodBiedry@users.noreply.github.com>
Date: Sun, 18 Oct 2026 23:36:13 +0200
Subject: [PATCH] Keep the crop of a PPTX video and apply it in the poster and
 playback (#972)

---
 crates/format/src/lib.rs        | 17 +++++++++++++++--
 crates/model/src/lib.rs         |  2 ++
 crates/pptx/src/read/shapes.rs  | 10 ++++++++--
 crates/pptx/src/write/shapes.rs |  2 +-
 crates/pptx/tests/roundtrip.rs  |  5 +++++
 crates/render/src/lib.rs        |  4 +++-
 crates/ui-egui/src/canvas.rs    |  2 +-
 crates/ui-egui/src/media.rs     | 22 ++++++++++++++++++++--
 crates/ui-egui/src/show.rs      |  2 +-
 9 files changed, 56 insertions(+), 10 deletions(-)

diff --git a/crates/format/src/lib.rs b/crates/format/src/lib.rs
index 5701a1ec..d78309aa 100644
--- a/crates/format/src/lib.rs
+++ b/crates/format/src/lib.rs
@@ -488,8 +488,9 @@ fn sane_shapes(shapes: &mut [deckcraft_model::Shape], depth: usize) {
             }
         }
         match &mut sh.kind {
-            deckcraft_model::ShapeKind::Picture { fill } => {
-                for c in &mut fill.crop {
+            deckcraft_model::ShapeKind::Picture { fill: deckcraft_model::style::PictureFill { crop, .. } }
+            | deckcraft_model::ShapeKind::Media(deckcraft_model::MediaClip { crop, .. }) => {
+                for c in crop {
                     *c = if c.is_finite() { c.clamp(-10.0, 1.0) } else { 0.0 };
                 }
             }
@@ -769,6 +770,18 @@ mod tests {
         assert!(load(&b).is_err());
     }
 
+    /// A video's crop is brought into the same range as a picture's (#972).
+    #[test]
+    fn a_video_crop_is_repaired_like_a_picture_crop() {
+        use deckcraft_model::{MediaClip, Shape};
+        let mut p = Presentation::default();
+        let clip = MediaClip { video: true, crop: [f64::NAN, 0.25, -1e9, 0.0], ..Default::default() };
+        Arc::make_mut(&mut p.slides[0]).shapes.push(Shape { kind: ShapeKind::Media(clip), ..Default::default() });
+        let back = load(&save(&p).unwrap()).unwrap_or_else(|e| panic!("{e}"));
+        let ShapeKind::Media(m) = &back.slides[0].shapes.last().unwrap().kind else { panic!("media") };
+        assert_eq!(m.crop, [0.0, 0.25, -10.0, 0.0]);
+    }
+
     /// Non-finite numbers are written as `null` by serde_json; the file still opens, with each
     /// such number repaired (it failed as "invalid type: null, expected f64").
     #[test]
diff --git a/crates/model/src/lib.rs b/crates/model/src/lib.rs
index 275f9440..4023d8cb 100644
--- a/crates/model/src/lib.rs
+++ b/crates/model/src/lib.rs
@@ -231,6 +231,8 @@ pub struct MediaClip {
     pub video: bool,
     /// Poster frame image.
     pub poster: Option<MediaId>,
+    /// Crop of the picture (left, top, right, bottom as fractions), PowerPoint's `srcRect` on the video.
+    pub crop: [f64; 4],
     pub trim_start_ms: u32,
     pub trim_end_ms: u32,
     pub fade_in_ms: u32,
diff --git a/crates/pptx/src/read/shapes.rs b/crates/pptx/src/read/shapes.rs
index 3f7072f4..50e6e250 100644
--- a/crates/pptx/src/read/shapes.rs
+++ b/crates/pptx/src/read/shapes.rs
@@ -347,8 +347,14 @@ fn pic(imp: &mut Imp, part: &Part, ctx: &mut IdCtx, e: &El) -> Shape {
     if vf.is_some() || af.is_some() || p14.is_some() {
         let media = p14.and_then(|m| dml::media_ref(imp, part, m)).or_else(|| vf.or(af).and_then(|f| dml::media_ref(imp, part, f)));
         if let Some(media) = media {
-            let mut clip =
-                MediaClip { media, video: vf.is_some() || af.is_none(), poster: pf.as_ref().map(|p| p.media), volume: 1.0, ..Default::default() };
+            let mut clip = MediaClip {
+                media,
+                video: vf.is_some() || af.is_none(),
+                poster: pf.as_ref().map(|p| p.media),
+                crop: pf.as_ref().map(|p| p.crop).unwrap_or_default(),
+                volume: 1.0,
+                ..Default::default()
+            };
             if let Some(m) = p14 {
                 if let Some(t) = m.child("trim") {
                     clip.trim_start_ms = ms(t.attr("st"));
diff --git a/crates/pptx/src/write/shapes.rs b/crates/pptx/src/write/shapes.rs
index 3c3f95eb..14710cfa 100644
--- a/crates/pptx/src/write/shapes.rs
+++ b/crates/pptx/src/write/shapes.rs
@@ -828,7 +828,7 @@ fn media(w: &mut W, x: &mut Exp, o: &mut Out, id: u32, s: &Shape, m: &deckcraft_
     }
     w.close("p:nvPr");
     w.close("p:nvPicPr");
-    let poster = deckcraft_model::style::PictureFill { media: m.poster.unwrap_or_default(), ..Default::default() };
+    let poster = deckcraft_model::style::PictureFill { media: m.poster.unwrap_or_default(), crop: m.crop, ..Default::default() };
     dml::blip_fill(w, x, o, "p:blipFill", &poster);
     let mut s3 = s.clone();
     s3.fill = None;
diff --git a/crates/pptx/tests/roundtrip.rs b/crates/pptx/tests/roundtrip.rs
index 697dad20..f4d2c2b7 100644
--- a/crates/pptx/tests/roundtrip.rs
+++ b/crates/pptx/tests/roundtrip.rs
@@ -256,6 +256,7 @@ pub fn rich_deck() -> Presentation {
         media: video,
         video: true,
         poster: Some(img),
+        crop: [0.1, 0.0, 0.2, 0.25],
         volume: 1.0,
         trim_start_ms: 500,
         fade_in_ms: 250,
@@ -505,6 +506,10 @@ fn pictures_media_and_ink_round_trip() {
     assert_eq!((m.trim_start_ms, m.fade_in_ms), (500, 250));
     assert!(q.media(m.media).is_some_and(|x| x.data.starts_with(b"\x00\x00\x00\x18ftyp")));
     assert!(m.poster.is_some());
+    // The crop of the video survives the round trip (#972).
+    for (got, want) in m.crop.iter().zip([0.1, 0.0, 0.2, 0.25]) {
+        assert!((got - want).abs() < 1e-4, "video crop {:?}", m.crop);
+    }
     // Ink comes back as freeform lines in a group. A flat 0.5 stroke keeps the pen width.
     let ink = by_name(&q.slides[2], "Ink");
     let ShapeKind::Group { children, .. } = &ink.kind else { panic!("ink is not a group: {:?}", ink.kind) };
diff --git a/crates/render/src/lib.rs b/crates/render/src/lib.rs
index cf124a9f..907a8c40 100644
--- a/crates/render/src/lib.rs
+++ b/crates/render/src/lib.rs
@@ -1094,8 +1094,10 @@ impl Renderer {
                 ctx.set_transform(m);
                 let bounds = Rect::new(0.0, 0.0, w, h);
                 if let Some(p) = mc.poster {
-                    let pf = deckcraft_model::style::PictureFill { media: p, ..Default::default() };
+                    let pf = deckcraft_model::style::PictureFill { media: p, crop: mc.crop, ..Default::default() };
+                    ctx.push_clip_layer(&outline);
                     paint::picture(ctx, f.pres, &pf, bounds, m, None);
+                    ctx.pop_layer();
                 } else if mc.video {
                     ctx.set_paint(peniko::Color::from_rgba8(20, 20, 24, 255));
                     ctx.fill_rect(&bounds);
diff --git a/crates/ui-egui/src/canvas.rs b/crates/ui-egui/src/canvas.rs
index ba66aad8..1e5522e6 100644
--- a/crates/ui-egui/src/canvas.rs
+++ b/crates/ui-egui/src/canvas.rs
@@ -371,7 +371,7 @@ fn media_frames(app: &SlideApp, painter: &egui::Painter, xf: Xf) {
     }
     for (id, x, clip) in crate::media::slide_media(&d.doc, d.selection.slide) {
         if clip.video {
-            crate::media::paint_frame(painter, &app.media, id, screen_rect(xf, &x));
+            crate::media::paint_frame(painter, &app.media, id, screen_rect(xf, &x), clip.crop);
         }
     }
 }
diff --git a/crates/ui-egui/src/media.rs b/crates/ui-egui/src/media.rs
index 7fd8fda7..30130d72 100644
--- a/crates/ui-egui/src/media.rs
+++ b/crates/ui-egui/src/media.rs
@@ -363,9 +363,21 @@ pub fn clock(secs: f64) -> String {
     format!("{:02}:{:05.2}", (s / 60.0) as u32, s % 60.0)
 }
 
-/// Draw the playing video frame of `id` into `rect` (letterboxed to the frame's aspect).
-pub fn paint_frame(painter: &egui::Painter, host: &MediaHost, id: ShapeId, rect: Rect) -> bool {
+/// The part of a video frame a picture crop (left, top, right, bottom fractions) leaves visible.
+fn crop_uv(crop: [f64; 4]) -> Rect {
+    let [l, t, r, b] = crop.map(|v| if v.is_finite() { v.clamp(0.0, 0.99) as f32 } else { 0.0 });
+    Rect::from_min_max(pos2(l, t), pos2((1.0 - r).max(l + 0.01), (1.0 - b).max(t + 0.01)))
+}
+
+/// Draw the playing video frame of `id` into `rect`: letterboxed to the frame's aspect, or, when
+/// the video is cropped, the cropped part stretched over the whole box as PowerPoint shows it.
+pub fn paint_frame(painter: &egui::Painter, host: &MediaHost, id: ShapeId, rect: Rect, crop: [f64; 4]) -> bool {
     let Some(tex) = host.texture(id) else { return false };
+    if crop.iter().any(|v| *v != 0.0) {
+        painter.rect_filled(rect, CornerRadius::ZERO, Color32::BLACK);
+        painter.image(tex.id(), rect, crop_uv(crop), Color32::WHITE);
+        return true;
+    }
     let [w, h] = tex.size();
     let (w, h) = (w.max(1) as f32, h.max(1) as f32);
     let k = (rect.width() / w).min(rect.height() / h);
@@ -512,6 +524,12 @@ mod tests {
 
     use super::*;
 
+    #[test]
+    fn a_video_crop_shows_only_the_cropped_part_of_the_frame() {
+        assert_eq!(crop_uv([0.0; 4]), Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)));
+        assert_eq!(crop_uv([0.25, 0.5, 0.25, 0.0]), Rect::from_min_max(pos2(0.25, 0.5), pos2(0.75, 1.0)));
+    }
+
     /// 16-bit mono WAV of a constant level, `secs` long at 8 kHz.
     fn wav_level(secs: f64, amp: f32) -> Vec<u8> {
         let rate = 8_000u32;
diff --git a/crates/ui-egui/src/show.rs b/crates/ui-egui/src/show.rs
index 51f859af..75df8677 100644
--- a/crates/ui-egui/src/show.rs
+++ b/crates/ui-egui/src/show.rs
@@ -851,7 +851,7 @@ pub fn ui(app: &mut SlideApp, ui: &mut Ui) {
                 } else {
                     slide_box(srect, uv, sw, sh, x.x as f32, x.y as f32, x.w as f32, x.h as f32)
                 };
-                crate::media::paint_frame(&painter, &app.media, *id, r);
+                crate::media::paint_frame(&painter, &app.media, *id, r, clip.crop);
             }
             // Play/pause on the animated GIF under the pointer, and the audio/video bar.
             // Slide Show ▸ Show Media Controls hides both (the click still plays a clip).