Expose delay/loop metadata for animated images #1905

docs/changelog.md

@@ -9,6 +9,9 @@ Requires libvips v8.9.0.
 * Drop support for Node.js 8.
   [#1910](https://github.com/lovell/sharp/issues/1910)
 
+* Expose `delay` and `loop` metadata for animated images.
+  [#1905](https://github.com/lovell/sharp/issues/1905)
+
 * Ensure correct colour output for 16-bit, 2-channel PNG input with ICC profile.
   [#2013](https://github.com/lovell/sharp/issues/2013)
 

src/metadata.cc

@@ -77,6 +77,12 @@ class MetadataWorker : public Nan::AsyncWorker {
       if (image.get_typeof(VIPS_META_PAGE_HEIGHT) == G_TYPE_INT) {
         baton->pageHeight = image.get_int(VIPS_META_PAGE_HEIGHT);
       }
+      if (image.get_typeof("loop") == G_TYPE_INT) {
+        baton->loop = image.get_int("loop");
+      }
+      if (image.get_typeof("delay") == VIPS_TYPE_ARRAY_INT) {
+        baton->delay = image.get_array_int("delay");
+      }
       if (image.get_typeof("heif-primary") == G_TYPE_INT) {
         baton->pagePrimary = image.get_int("heif-primary");
       }
@@ -169,6 +175,17 @@ class MetadataWorker : public Nan::AsyncWorker {
       if (baton->pageHeight > 0) {
         Set(info, New("pageHeight").ToLocalChecked(), New<v8::Uint32>(baton->pageHeight));
       }
+      if (baton->loop >= 0) {
+        Set(info, New("loop").ToLocalChecked(), New<v8::Uint32>(baton->loop));
+      }
+      if (!baton->delay.empty()) {
+        int i = 0;
+        v8::Local<v8::Array> delay = New<v8::Array>(baton->delay.size());
+        for (int const d : baton->delay) {
+          Set(delay, i++, New<v8::Number>(d));
+        }
+        Set(info, New("delay").ToLocalChecked(), delay);
+      }
       if (baton->pagePrimary > -1) {
         Set(info, New("pagePrimary").ToLocalChecked(), New<v8::Uint32>(baton->pagePrimary));
       }

src/metadata.h

@@ -36,6 +36,8 @@ struct MetadataBaton {
   int paletteBitDepth;
   int pages;
   int pageHeight;
+  int loop;
+  std::vector<int> delay;
   int pagePrimary;
   bool hasProfile;
   bool hasAlpha;
@@ -62,6 +64,7 @@ struct MetadataBaton {
     paletteBitDepth(0),
     pages(0),
     pageHeight(0),
+    loop(-1),
     pagePrimary(-1),
     hasProfile(false),
     hasAlpha(false),

test/fixtures/index.js

@@ -102,6 +102,7 @@ module.exports = {
   inputGif: getPath('Crash_test.gif'), // http://upload.wikimedia.org/wikipedia/commons/e/e3/Crash_test.gif
   inputGifGreyPlusAlpha: getPath('grey-plus-alpha.gif'), // http://i.imgur.com/gZ5jlmE.gif
   inputGifAnimated: getPath('rotating-squares.gif'), // CC0 https://loading.io/spinner/blocks/-rotating-squares-preloader-gif
+  inputGifAnimatedLoop3: getPath('animated-loop-3.gif'), // CC-BY-SA-4.0 Petrus3743 https://commons.wikimedia.org/wiki/File:01-Goldener_Schnitt_Formel-Animation.gif
   inputSvg: getPath('check.svg'), // http://dev.w3.org/SVG/tools/svgweb/samples/svg-files/check.svg
   inputSvgWithEmbeddedImages: getPath('struct-image-04-t.svg'), // https://dev.w3.org/SVG/profiles/1.2T/test/svg/struct-image-04-t.svg
 

test/unit/metadata.js

@@ -232,6 +232,55 @@ describe('Image metadata', function () {
       done();
     });
   });
+
+  it('Animated GIF', () =>
+    sharp(fixtures.inputGifAnimated)
+      .metadata()
+      .then(({
+        format, width, height, space, channels, depth,
+        isProgressive, pages, pageHeight, loop, delay,
+        hasProfile, hasAlpha
+      }) => {
+        assert.strictEqual(format, 'gif');
+        assert.strictEqual(width, 80);
+        assert.strictEqual(height, 80);
+        assert.strictEqual(space, 'srgb');
+        assert.strictEqual(channels, 4);
+        assert.strictEqual(depth, 'uchar');
+        assert.strictEqual(isProgressive, false);
+        assert.strictEqual(pages, 30);
+        assert.strictEqual(pageHeight, 80);
+        assert.strictEqual(loop, 0);
+        assert.deepStrictEqual(delay, Array(30).fill(30));
+        assert.strictEqual(hasProfile, false);
+        assert.strictEqual(hasAlpha, true);
+      })
+  );
+
+  it('Animated GIF with limited looping', () =>
+    sharp(fixtures.inputGifAnimatedLoop3)
+      .metadata()
+      .then(({
+        format, width, height, space, channels, depth,
+        isProgressive, pages, pageHeight, loop, delay,
+        hasProfile, hasAlpha
+      }) => {
+        assert.strictEqual(format, 'gif');
+        assert.strictEqual(width, 370);
+        assert.strictEqual(height, 285);
+        assert.strictEqual(space, 'srgb');
+        assert.strictEqual(channels, 4);
+        assert.strictEqual(depth, 'uchar');
+        assert.strictEqual(isProgressive, false);
+        assert.strictEqual(pages, 10);
+        assert.strictEqual(pageHeight, 285);
+        assert.strictEqual(loop, 3);
+        assert.deepStrictEqual(delay, [...Array(9).fill(3000), 15000]);
+        assert.strictEqual(hasProfile, false);
+        assert.strictEqual(hasAlpha, true);
+      })
+  );
+
   it('vips', () =>
     sharp(fixtures.inputV)
       .metadata()