From 885c953cacb490a25907c37c3041d656ddd74d19 Mon Sep 17 00:00:00 2001
From: Wonwoo Choi <chwo9843@gmail.com>
Date: Tue, 29 Oct 2024 16:37:41 +0900
Subject: [PATCH] jxl-render: Fix requested color encoding not applied in some
 cases (#369)

* jxl-render: Fix requested color encoding not applied in some cases

* Update CHANGELOG.md
---
 CHANGELOG.md                   |  3 +++
 crates/jxl-render/src/image.rs | 14 +++++++++-----
 crates/jxl-render/src/lib.rs   |  6 +-----
 crates/jxl-render/src/util.rs  |  6 ++++--
 4 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3652f931..0ba902db 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - `jxl-color`: Use better PQ to HLG method (#348).
 
+### Fixed
+- `jxl-render`: Fix requested color encoding not applied in some cases (#369).
+
 ## [0.9.1] - 2024-10-12
 
 ### Fixed
diff --git a/crates/jxl-render/src/image.rs b/crates/jxl-render/src/image.rs
index a8f71756..59aecdd1 100644
--- a/crates/jxl-render/src/image.rs
+++ b/crates/jxl-render/src/image.rs
@@ -730,17 +730,21 @@ impl<S: Sample> RenderedImage<S> {
             }
         }
 
-        if !frame_header.frame_type.is_normal_frame() || frame_header.resets_canvas {
+        let skip_blending =
+            !frame_header.frame_type.is_normal_frame() || frame_header.resets_canvas;
+
+        if !(grid.ct_done() || frame_header.save_before_ct || skip_blending && frame_header.is_last)
+        {
+            util::convert_color_for_record(image_header, frame_header.do_ycbcr, &mut grid, pool)?;
+        }
+
+        if skip_blending {
             grid.blend_done = true;
             let image = Arc::new(grid);
             *grid_lock = FrameRender::Blended(Arc::clone(&image));
             return Ok(image);
         }
 
-        if !grid.ct_done() {
-            util::convert_color_for_record(image_header, frame_header.do_ycbcr, &mut grid, pool)?;
-        }
-
         let image = crate::blend::blend(
             image_header,
             self.image.refs.clone(),
diff --git a/crates/jxl-render/src/lib.rs b/crates/jxl-render/src/lib.rs
index 4d2db6a6..cd2024cc 100644
--- a/crates/jxl-render/src/lib.rs
+++ b/crates/jxl-render/src/lib.rs
@@ -805,10 +805,6 @@ impl RenderContext {
             tracing::trace!(requested_color_encoding = ?self.requested_color_encoding);
             tracing::trace!(do_ycbcr = frame_header.do_ycbcr);
 
-            if grid.ct_done() {
-                return Ok(grid);
-            }
-
             let mut transform = jxl_color::ColorTransform::builder();
             transform.set_srgb_icc(!self.cms.supports_linear_tf());
             transform.from_pq(self.suggested_hdr_tf() == Some(jxl_color::TransferFunction::Pq));
@@ -818,7 +814,7 @@ impl RenderContext {
                 &metadata.opsin_inverse_matrix,
                 &metadata.tone_mapping,
             )?;
-            if transform.is_noop() && !frame_header.do_ycbcr {
+            if grid.ct_done() || (transform.is_noop() && !frame_header.do_ycbcr) {
                 return Ok(grid);
             }
 
diff --git a/crates/jxl-render/src/util.rs b/crates/jxl-render/src/util.rs
index 0d6e0875..040bd740 100644
--- a/crates/jxl-render/src/util.rs
+++ b/crates/jxl-render/src/util.rs
@@ -325,6 +325,8 @@ pub(crate) fn convert_color_for_record(
         if metadata.colour_encoding.colour_space() == ColourSpace::Grey {
             fb.remove_color_channels(1);
         }
+
+        fb.set_ct_done(true);
     } else if metadata.xyb_encoded {
         // want_icc = false || is_last = true
         // in any case, blending does not occur when want_icc = true
@@ -367,10 +369,10 @@ pub(crate) fn convert_color_for_record(
             fb.remove_color_channels(output_channels);
             Ok(())
         })?;
+
+        fb.set_ct_done(true);
     }
 
-    // color transform is done
-    fb.set_ct_done(true);
     Ok(())
 }