Fix gif encoder to handle stride padding

Author: lilith

imageflow_core/src/codecs/gif.rs

@@ -132,14 +132,14 @@ impl Encoder for GifEncoder{
                     pix[0] = pix[2];
                     pix[2] = a;
                 }
-                f = ::gif::Frame::from_rgb(frame.w as u16, frame.h as u16, &mut pixels);
+                f = from_rgb_with_stride(frame.w as u16, frame.h as u16, &mut pixels, frame.stride as usize);
             }else {
                 for pix in pixels.chunks_mut(4) {
                     let a = pix[0];
                     pix[0] = pix[2];
                     pix[2] = a;
                 }
-                f = ::gif::Frame::from_rgba(frame.w as u16, frame.h as u16, &mut pixels);
+                f = from_rgba_with_stride(frame.w as u16, frame.h as u16, &mut pixels, frame.stride as usize);
             }
 
             let mut encoder = ::gif::Encoder::new(io, frame.w as u16, frame.h as u16, &[]).unwrap();
@@ -159,3 +159,22 @@ impl Encoder for GifEncoder{
     }
 }
 
+
+fn remove_padding(width: u16, pixels: &[u8], stride: usize) -> Vec<u8>{
+    pixels.chunks(stride).flat_map(|s| s[0..width as usize * 4].iter().map(|v| *v)).collect()
+}
+    /// Creates a frame from pixels in RGBA format.
+    ///
+    /// *Note: This method is not optimized for speed.*
+    pub fn from_rgba_with_stride(width: u16, height: u16, pixels: &mut [u8], stride: usize) -> ::gif::Frame<'static> {
+        let mut without_padding = remove_padding(width, pixels, stride);
+        ::gif::Frame::from_rgba(width, height, &mut without_padding)
+    }
+
+/// Creates a frame from pixels in RGB format.
+///
+/// *Note: This method is not optimized for speed.*
+pub fn from_rgb_with_stride(width: u16, height: u16, pixels: &[u8], stride: usize) -> ::gif::Frame<'static> {
+    let mut without_padding = remove_padding(width, pixels, stride);
+    ::gif::Frame::from_rgb(width, height, &mut without_padding)
+}

imageflow_core/tests/visuals.rs

@@ -285,6 +285,41 @@ fn test_jpeg_rotation() {
     }
 
 }
+//
+//#[test]
+//fn test_gif_ir4(){
+//        let matched = compare(Some(s::IoEnum::Url("https://s3-us-west-2.amazonaws.com/imageflow-resources/test_inputs/waterhouse.jpg".to_owned())), 500,
+//                              "Read".to_owned(), true, DEBUG_GRAPH, vec![
+//                s::Node::CommandString{
+//                    kind: s::CommandStringKind::ImageResizer4,
+//                    value: "width=200&height=200&format=gif".to_owned(),
+//                    decode: Some(0),
+//                    encode: None //Some(1)
+//                }
+//            ]
+//        );
+//        assert!(matched);
+//
+//}
+
+#[test]
+fn smoke_test_gif_ir4(){
+
+    let steps = vec![
+        s::Node::CommandString{
+            kind: s::CommandStringKind::ImageResizer4,
+            value: "width=200&height=200&format=gif".to_owned(),
+            decode: Some(0),
+            encode: Some(1)
+        }
+    ];
+
+    smoke_test(Some(s::IoEnum::Url("https://s3-us-west-2.amazonaws.com/imageflow-resources/test_inputs/waterhouse.jpg".to_owned())),
+               Some(s::IoEnum::OutputBuffer),
+               DEBUG_GRAPH,
+               steps,
+    );
+}
 
 
 #[test]