diff --git a/src/aspect_ratio.rs b/src/aspect_ratio.rs
new file mode 100644
index 0000000..7859236
--- /dev/null
+++ b/src/aspect_ratio.rs
@@ -0,0 +1,92 @@
+// SPDX-FileCopyrightText: 2025 Simon Repp
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+const SPECIAL_ASPECT_RATIOS: [(f32, &str); 10] = [
+    (2.37, "64:27"),
+    (1.78, "16:9"),
+    (1.66, "5:3"),
+    (1.5, "3:2"),
+    (1.33, "4:3"),
+    (0.75, "3:4"),
+    (0.67, "2:3"),
+    (0.6, "3:5"),
+    (0.56, "9:16"),
+    (0.42, "27:64")
+];
+
+#[derive(Clone, Debug)]
+pub enum AspectRatio {
+    /// Representation stores the user-supplied input (e.g. 16:9) while value stores
+    /// the numeric result of dividing width parts by height parts (e.g. 1.78).
+    Custom {
+        representation: String,
+        value: f32
+    },
+    // 16:9
+    Default
+}
+
+impl AspectRatio {
+    /// For some common, handpicked aspect ratios we try to automatically display
+    /// them to the user (e.g. 16:9 instead of 1.7777778 or such).
+    pub fn approximate_representation(numeric_ratio: f32) -> String {
+        // Could be adjusted up/down if we feel our approximations are too
+        // strictly/loosely determined.
+        const APPROXIMATION_TOLERANCE: f32 = 0.01;
+
+        for ratio in SPECIAL_ASPECT_RATIOS {
+            if (ratio.0 - numeric_ratio).abs() <= APPROXIMATION_TOLERANCE {
+                return ratio.1.to_string();
+            }
+        }
+
+        format!("{numeric_ratio:.2}")
+    }
+
+    /// Parse a representation such as '1.78', '16:9' or '16/9' into an
+    /// [AspectRatio] struct or return an error if the format is
+    /// unsupported.
+    pub fn from_representation(representation: &str) -> Result<AspectRatio, String> {
+        if let Ok(ratio) = representation.parse::<f32>() {
+            let aspect_ratio = AspectRatio::Custom {
+                representation: representation.to_owned(),
+                value: ratio
+            };
+
+            return Ok(aspect_ratio);
+        }
+
+        let mut parts = representation.split(|c| c == '/' || c == ':');
+        if let (Some(dividend), Some(divisor), None) = (parts.next(), parts.next(), parts.next()) {
+            if let (Ok(dividend), Ok(divisor)) = (dividend.parse::<f32>(), divisor.parse::<f32>()) {
+                let aspect_ratio = AspectRatio::Custom {
+                    representation: representation.to_owned(),
+                    value: dividend / divisor
+                };
+
+                return Ok(aspect_ratio);
+            }
+        }
+
+        let error = format!("'{representation}' is not understood, allowed aspect formats are e.g. '1.78', '16:9' or '16/9')");
+        Err(error)
+    }
+
+    /// Return the raw aspect ratio number ("width parts divided by height parts").
+    pub fn numeric(&self) -> f32 {
+        match self {
+            AspectRatio::Default => 16.0/9.0,
+            AspectRatio::Custom { value, .. } => *value
+        }
+    }
+
+    /// Return the aspect ratio as it was supplied by the user (i.e. in a
+    /// usually more meaningful/understandable representation such as 16:9
+    /// instead of 1.78).
+    pub fn representation(&self) -> &str {
+        match self {
+            AspectRatio::Default => "16:9",
+            AspectRatio::Custom { representation, .. } => representation
+        }
+    }
+}
diff --git a/src/collection.rs b/src/collection.rs
index a755df2..91b9292 100644
--- a/src/collection.rs
+++ b/src/collection.rs
@@ -1050,8 +1050,8 @@ impl Collection {
         subcollections
     }
 
-    /// Returns all public videos in the collection, i.e. those that are not
-    /// marked as offline or unlisted.
+    /// Returns all public videos (= not marked as offline or unlisted)
+    /// contained directly in the collection.
     pub fn public_videos(&self) -> impl Iterator<Item = &Arc<Video>> {
         self.videos.iter().filter(|video| video.public_local())
     }
diff --git a/src/main.rs b/src/main.rs
index cfec3ff..6a6f38a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,6 +7,7 @@ use clap::Parser;
 use sys_locale::get_locale;
 
 mod args;
+mod aspect_ratio;
 mod banner;
 mod browser_support;
 mod build;
@@ -46,6 +47,7 @@ mod watcher;
 mod workers;
 
 use args::Args;
+use aspect_ratio::AspectRatio;
 use banner::Banner;
 use cache::{Cache, PosterAssetsCached, PosterSourceCached, VideoMetaCached};
 use collection::Collection;
@@ -67,7 +69,7 @@ use poster_assets::{PosterAsset, PosterAssets};
 use poster_file::PosterFile;
 use poster_meta::PosterMeta;
 use processing::{Job, JobKind, Processing, Progress};
-use site::{AspectRatio, Site, SiteContent};
+use site::{Site, SiteContent};
 use site_path::SitePath;
 use site_url::SiteUrl;
 use subtitles::SubtitleFile;
diff --git a/src/site.rs b/src/site.rs
index e6443aa..0243b49 100644
--- a/src/site.rs
+++ b/src/site.rs
@@ -8,6 +8,7 @@ use std::sync::Arc;
 use indoc::indoc;
 
 use crate::{
+    AspectRatio,
     Context,
     Collection,
     Font,
@@ -37,15 +38,6 @@ const SITE_OPTIONS: &[&str] = &[
     "theme"
 ];
 
-#[derive(Clone, Debug)]
-pub enum AspectRatio {
-    Custom {
-        representation: String,
-        value: f32
-    },
-    Default
-}
-
 #[derive(Clone, Debug)]
 pub struct Site {
     pub base_url: Option<SiteUrl>,
@@ -77,77 +69,6 @@ pub enum SiteContent {
     Video(Arc<Video>)
 }
 
-impl AspectRatio {
-    /// For some common, handpicked aspect ratios we try to automatically display
-    /// them to the user (e.g. 16:9 instead of 1.7777778 or such).
-    pub fn approximate_representation(numeric_ratio: f32) -> String {
-        const RATIOS: [(f32, &str); 10] = [
-            (2.37, "64:27"),
-            (1.78, "16:9"),
-            (1.66, "5:3"),
-            (1.5, "3:2"),
-            (1.33, "4:3"),
-            (0.75, "3:4"),
-            (0.67, "2:3"),
-            (0.6, "3:5"),
-            (0.56, "9:16"),
-            (0.42, "27:64")
-        ];
-
-        // Could be adjusted up/down if we feel our approximations are too
-        // strictly/loosely determined.
-        const TOLERANCE: f32 = 0.01;
-
-        for ratio in RATIOS {
-            if (ratio.0 - numeric_ratio).abs() <= TOLERANCE {
-                return ratio.1.to_string();
-            }
-        }
-
-        format!("{numeric_ratio:.2}")
-    }
-
-    pub fn from_representation(representation: &str) -> Result<AspectRatio, String> {
-        if let Ok(ratio) = representation.parse::<f32>() {
-            let aspect_ratio = AspectRatio::Custom {
-                representation: representation.to_owned(),
-                value: ratio
-            };
-
-            return Ok(aspect_ratio);
-        }
-
-        let mut parts = representation.split(|c| c == '/' || c == ':');
-        if let (Some(dividend), Some(divisor), None) = (parts.next(), parts.next(), parts.next()) {
-            if let (Ok(dividend), Ok(divisor)) = (dividend.parse::<f32>(), divisor.parse::<f32>()) {
-                let aspect_ratio = AspectRatio::Custom {
-                    representation: representation.to_owned(),
-                    value: dividend / divisor
-                };
-
-                return Ok(aspect_ratio);
-            }
-        }
-
-        let error = format!("'{representation}' is not understood, allowed aspect formats are e.g. '1.78', '16:9' or '16/9')");
-        Err(error)
-    }
-
-    pub fn numeric(&self) -> f32 {
-        match self {
-            AspectRatio::Default => 16.0/9.0,
-            AspectRatio::Custom { value, .. } => *value
-        }
-    }
-
-    pub fn representation(&self) -> &str {
-        match self {
-            AspectRatio::Default => "16:9",
-            AspectRatio::Custom { representation, .. } => representation
-        }
-    }
-}
-
 impl Site {
     pub fn absolute_url_dir_unchecked(&self, dir: &str, site_path: &SitePath) -> String {
         self.base_url