pixels: Extend Image to allow for multiple frames (#36058)

Signed-off-by: rayguo17 <rayguo17@gmail.com>

components/compositing/compositor.rs

@@ -30,7 +30,7 @@ use fnv::FnvHashMap;
 use ipc_channel::ipc::{self, IpcSharedMemory};
 use libc::c_void;
 use log::{debug, info, trace, warn};
-use pixels::{CorsStatus, Image, PixelFormat};
+use pixels::{CorsStatus, Image, ImageFrame, PixelFormat};
 use profile_traits::time::{self as profile_time, ProfilerCategory};
 use profile_traits::time_profile;
 use script_traits::{
@@ -1454,7 +1454,12 @@ impl IOCompositor {
                 width: image.width(),
                 height: image.height(),
                 format: PixelFormat::RGBA8,
-                bytes: ipc::IpcSharedMemory::from_bytes(&image),
+                frames: vec![ImageFrame {
+                    delay: None,
+                    bytes: ipc::IpcSharedMemory::from_bytes(&image),
+                    width: image.width(),
+                    height: image.height(),
+                }],
                 id: None,
                 cors_status: CorsStatus::Safe,
             }))

components/net/image_cache.rs

@@ -55,14 +55,15 @@ fn set_webrender_image_key(compositor_api: &CrossProcessCompositorApi, image: &m
         return;
     }
     let mut bytes = Vec::new();
+    let frame_bytes = image.bytes();
     let is_opaque = match image.format {
         PixelFormat::BGRA8 => {
-            bytes.extend_from_slice(&image.bytes);
+            bytes.extend_from_slice(&frame_bytes);
             pixels::rgba8_premultiply_inplace(bytes.as_mut_slice())
         },
         PixelFormat::RGB8 => {
-            bytes.reserve(image.bytes.len() / 3 * 4);
-            for bgr in image.bytes.chunks(3) {
+            bytes.reserve(frame_bytes.len() / 3 * 4);
+            for bgr in frame_bytes.chunks(3) {
                 bytes.extend_from_slice(&[bgr[2], bgr[1], bgr[0], 0xff]);
             }
 

components/pixels/lib.rs

@@ -3,10 +3,13 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use std::borrow::Cow;
-use std::fmt;
+use std::io::Cursor;
+use std::time::Duration;
+use std::{cmp, fmt, vec};
 
 use euclid::default::{Point2D, Rect, Size2D};
-use image::ImageFormat;
+use image::codecs::gif::GifDecoder;
+use image::{AnimationDecoder as _, ImageFormat};
 use ipc_channel::ipc::IpcSharedMemory;
 use log::debug;
 use malloc_size_of_derive::MallocSizeOf;
@@ -120,11 +123,33 @@ pub struct Image {
     pub width: u32,
     pub height: u32,
     pub format: PixelFormat,
-    #[ignore_malloc_size_of = "Defined in ipc-channel"]
-    pub bytes: IpcSharedMemory,
     #[ignore_malloc_size_of = "Defined in webrender_api"]
     pub id: Option<ImageKey>,
     pub cors_status: CorsStatus,
+    pub frames: Vec<ImageFrame>,
+}
+
+#[derive(Clone, Deserialize, MallocSizeOf, Serialize)]
+pub struct ImageFrame {
+    pub delay: Option<Duration>,
+    #[ignore_malloc_size_of = "Defined in ipc-channel"]
+    pub bytes: IpcSharedMemory,
+    pub width: u32,
+    pub height: u32,
+}
+
+impl Image {
+    pub fn should_animate(&self) -> bool {
+        self.frames.len() > 1
+    }
+
+    pub fn bytes(&self) -> IpcSharedMemory {
+        self.frames
+            .first()
+            .expect("Should have at least one frame")
+            .bytes
+            .clone()
+    }
 }
 
 impl fmt::Debug for Image {
@@ -157,22 +182,31 @@ pub fn load_from_memory(buffer: &[u8], cors_status: CorsStatus) -> Option<Image>
             debug!("{}", msg);
             None
         },
-        Ok(_) => match image::load_from_memory(buffer) {
-            Ok(image) => {
-                let mut rgba = image.into_rgba8();
-                rgba8_byte_swap_colors_inplace(&mut rgba);
-                Some(Image {
-                    width: rgba.width(),
-                    height: rgba.height(),
-                    format: PixelFormat::BGRA8,
-                    bytes: IpcSharedMemory::from_bytes(&rgba),
-                    id: None,
-                    cors_status,
-                })
-            },
-            Err(e) => {
-                debug!("Image decoding error: {:?}", e);
-                None
+        Ok(format) => match format {
+            ImageFormat::Gif => decode_gif(buffer, cors_status),
+            _ => match image::load_from_memory(buffer) {
+                Ok(image) => {
+                    let mut rgba = image.into_rgba8();
+                    rgba8_byte_swap_colors_inplace(&mut rgba);
+                    let frame = ImageFrame {
+                        delay: None,
+                        bytes: IpcSharedMemory::from_bytes(&rgba),
+                        width: rgba.width(),
+                        height: rgba.height(),
+                    };
+                    Some(Image {
+                        width: rgba.width(),
+                        height: rgba.height(),
+                        format: PixelFormat::BGRA8,
+                        frames: vec![frame],
+                        id: None,
+                        cors_status,
+                    })
+                },
+                Err(e) => {
+                    debug!("Image decoding error: {:?}", e);
+                    None
+                },
             },
         },
     }
@@ -257,6 +291,57 @@ fn is_webp(buffer: &[u8]) -> bool {
     buffer[8..].len() >= len && &buffer[8..12] == b"WEBP"
 }
 
+fn decode_gif(buffer: &[u8], cors_status: CorsStatus) -> Option<Image> {
+    let Ok(decoded_gif) = GifDecoder::new(Cursor::new(buffer)) else {
+        return None;
+    };
+    let mut width = 0;
+    let mut height = 0;
+
+    // This uses `map_while`, because the first non-decodable frame seems to
+    // send the frame iterator into an infinite loop. See
+    // <https://github.com/image-rs/image/issues/2442>.
+    let frames: Vec<ImageFrame> = decoded_gif
+        .into_frames()
+        .map_while(|decoded_frame| {
+            let mut frame = match decoded_frame {
+                Ok(decoded_frame) => decoded_frame,
+                Err(error) => {
+                    debug!("decode GIF frame error: {error}");
+                    return None;
+                },
+            };
+            rgba8_byte_swap_colors_inplace(frame.buffer_mut());
+
+            let frame = ImageFrame {
+                bytes: IpcSharedMemory::from_bytes(frame.buffer()),
+                delay: Some(Duration::from(frame.delay())),
+                width: frame.buffer().width(),
+                height: frame.buffer().height(),
+            };
+
+            // The image size should be at least as large as the largest frame.
+            width = cmp::max(width, frame.width);
+            height = cmp::max(height, frame.height);
+            Some(frame)
+        })
+        .collect();
+
+    if frames.is_empty() {
+        debug!("Animated Image decoding error");
+        None
+    } else {
+        Some(Image {
+            width,
+            height,
+            cors_status,
+            frames,
+            id: None,
+            format: PixelFormat::BGRA8,
+        })
+    }
+}
+
 #[cfg(test)]
 mod test {
     use super::detect_image_format;

components/script/canvas_state.rs

@@ -292,7 +292,7 @@ impl CanvasState {
 
         let image_size = Size2D::new(img.width, img.height);
         let image_data = match img.format {
-            PixelFormat::BGRA8 => img.bytes.clone(),
+            PixelFormat::BGRA8 => img.bytes(),
             pixel_format => unimplemented!("unsupported pixel format ({:?})", pixel_format),
         };
 

components/script/dom/webglrenderingcontext.rs

@@ -619,7 +619,7 @@ impl WebGLRenderingContext {
 
                 let size = Size2D::new(img.width, img.height);
 
-                TexPixels::new(img.bytes.clone(), size, img.format, false)
+                TexPixels::new(img.bytes(), size, img.format, false)
             },
             // TODO(emilio): Getting canvas data is implemented in CanvasRenderingContext2D,
             // but we need to refactor it moving it to `HTMLCanvasElement` and support

components/webdriver_server/lib.rs

@@ -1677,7 +1677,7 @@ impl Handler {
             "Unexpected screenshot pixel format"
         );
 
-        let rgb = RgbaImage::from_raw(img.width, img.height, img.bytes.to_vec()).unwrap();
+        let rgb = RgbaImage::from_raw(img.width, img.height, img.bytes().to_vec()).unwrap();
         let mut png_data = Cursor::new(Vec::new());
         DynamicImage::ImageRgba8(rgb)
             .write_to(&mut png_data, ImageFormat::Png)