Validate all frames in APNGs

src/sanity_checks.rs

@@ -1,15 +1,14 @@
-use image::{DynamicImage, GenericImageView, ImageFormat, Pixel};
+use image::{codecs::png::PngDecoder, *};
 use log::{error, warn};
-use std::io::Cursor;
 
 /// Validate that the output png data still matches the original image
 pub fn validate_output(output: &[u8], original_data: &[u8]) -> bool {
- let (old_png, new_png) = rayon::join(
+ let (old_frames, new_frames) = rayon::join(
  || load_png_image_from_memory(original_data),
  || load_png_image_from_memory(output),
  );
 
- match (new_png, old_png) {
+ match (new_frames, old_frames) {
  (Err(new_err), _) => {
  error!("Failed to read output image for validation: {}", new_err);
  false
@@ -21,26 +20,40 @@ pub fn validate_output(output: &[u8], original_data: &[u8]) -> bool {
  warn!("Failed to read input image for validation: {}", old_err);
  true
  }
- (Ok(new_png), Ok(old_png)) => images_equal(&old_png, &new_png),
+ (Ok(new_frames), Ok(old_frames)) if new_frames.len() != old_frames.len() => false,
+ (Ok(new_frames), Ok(old_frames)) => {
+ for (a, b) in old_frames.iter().zip(new_frames) {
+ if !images_equal(&a, &b) {
+ return false;
+ }
+ }
+ true
+ }
  }
 }
 
-/// Loads a PNG image from memory to a [DynamicImage]
-fn load_png_image_from_memory(png_data: &[u8]) -> Result<DynamicImage, image::ImageError> {
- let mut reader = image::io::Reader::new(Cursor::new(png_data));
- reader.set_format(ImageFormat::Png);
- reader.no_limits();
- reader.decode()
+/// Loads a PNG image from memory to frames of [RgbaImage]
+fn load_png_image_from_memory(png_data: &[u8]) -> Result<Vec<RgbaImage>, image::ImageError> {
+ let decoder = PngDecoder::new(png_data)?;
+ if decoder.is_apng() {
+ decoder
+ .apng()
+ .into_frames()
+ .map(|f| f.map(|f| f.into_buffer()))
+ .collect()
+ } else {
+ DynamicImage::from_decoder(decoder).map(|i| vec![i.into_rgba8()])
+ }
 }
 
 /// Compares images pixel by pixel for equivalent content
-fn images_equal(old_png: &DynamicImage, new_png: &DynamicImage) -> bool {
+fn images_equal(old_png: &RgbaImage, new_png: &RgbaImage) -> bool {
  let a = old_png.pixels().filter(|x| {
- let p = x.2.channels();
+ let p = x.channels();
  !(p.len() == 4 && p[3] == 0)
  });
  let b = new_png.pixels().filter(|x| {
- let p = x.2.channels();
+ let p = x.channels();
  !(p.len() == 4 && p[3] == 0)
  });
  a.eq(b)