feat: add frameset

src/model/frameset.rs

@@ -0,0 +1,61 @@
+use serde::{Deserialize, Serialize};
+
+/// Set of video frames for seek preview
+///
+/// YouTube generates a set of images containing a grid of frames for each video.
+/// These images are used by the player for the seekbar preview.
+#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
+#[non_exhaustive]
+pub struct Frameset {
+    /// Url template of the frameset
+    ///
+    /// The `$M` placeholder has to be replaced with the page index (starting from 0).
+    pub url_template: String,
+    /// Width of a single frame in pixels
+    pub frame_width: u32,
+    /// Height of a single frame in pixels
+    pub frame_height: u32,
+    /// Number of pages (individual images)
+    pub page_count: u32,
+    /// Total number of frames in the set
+    pub total_count: u32,
+    /// Duration per frame in milliseconds
+    pub duration_per_frame: u32,
+    /// Number of frames in the x direction
+    pub frames_per_page_x: u32,
+    /// Number of frames in the y direction.
+    pub frames_per_page_y: u32,
+}
+
+/// Iterator producing frameset page urls
+pub struct FramesetUrls<'a> {
+    frameset: &'a Frameset,
+    i: u32,
+}
+
+impl Frameset {
+    /// Gets an iterator over the page URLs of the frameset
+    pub fn urls(&self) -> FramesetUrls {
+        FramesetUrls {
+            frameset: self,
+            i: 0,
+        }
+    }
+}
+
+impl Iterator for FramesetUrls<'_> {
+    type Item = String;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.i < self.frameset.page_count {
+            let url = self
+                .frameset
+                .url_template
+                .replace("$M", &self.i.to_string());
+            self.i += 1;
+            Some(url)
+        } else {
+            None
+        }
+    }
+}