Add pageHeight and pages to anim output response #3411

docs/api-output.md

@@ -24,7 +24,7 @@ A `Promise` is returned when `callback` is not provided.
 | Param | Type | Description |
 | --- | --- | --- |
 | fileOut | <code>string</code> | the path to write the image data to. |
-| [callback] | <code>function</code> | called on completion with two arguments `(err, info)`. `info` contains the output image `format`, `size` (bytes), `width`, `height`, `channels` and `premultiplied` (indicating if premultiplication was used). When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`. When using the attention crop strategy also contains `attentionX` and `attentionY`, the focal point of the cropped region. May also contain `textAutofitDpi` (dpi the font was rendered at) if image was created from text. |
+| [callback] | <code>function</code> | called on completion with two arguments `(err, info)`. `info` contains the output image `format`, `size` (bytes), `width`, `height`, `channels` and `premultiplied` (indicating if premultiplication was used). When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`. When using the attention crop strategy also contains `attentionX` and `attentionY`, the focal point of the cropped region. Animated output will also contain `pageHeight` and `pages`. May also contain `textAutofitDpi` (dpi the font was rendered at) if image was created from text. |
 
 **Example**  
 ```js
@@ -59,6 +59,7 @@ See [withMetadata](#withmetadata) for control over this.
 - `info` contains the output image `format`, `size` (bytes), `width`, `height`,
 `channels` and `premultiplied` (indicating if premultiplication was used).
 When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+Animated output will also contain `pageHeight` and `pages`.
 May also contain `textAutofitDpi` (dpi the font was rendered at) if image was created from text.
 
 A `Promise` is returned when `callback` is not provided.

docs/changelog.md

@@ -6,6 +6,9 @@ Requires libvips v8.15.2
 
 ### v0.33.5 - TBD
 
+* Add `pageHeight` and `pages` to response of multi-page output.
+  [#3411](https://github.com/lovell/sharp/issues/3411)
+
 * Ensure option to force use of a globally-installed libvips works correctly.
   [#4111](https://github.com/lovell/sharp/pull/4111)
   [@project0](https://github.com/project0)

lib/output.js

@@ -65,6 +65,7 @@ const bitdepthFromColourCount = (colours) => 1 << 31 - Math.clz32(Math.ceil(Math
  * `channels` and `premultiplied` (indicating if premultiplication was used).
  * When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
  * When using the attention crop strategy also contains `attentionX` and `attentionY`, the focal point of the cropped region.
+ * Animated output will also contain `pageHeight` and `pages`.
  * May also contain `textAutofitDpi` (dpi the font was rendered at) if image was created from text.
  * @returns {Promise<Object>} - when no callback is provided
  * @throws {Error} Invalid parameters
@@ -109,6 +110,7 @@ function toFile (fileOut, callback) {
  * - `info` contains the output image `format`, `size` (bytes), `width`, `height`,
  * `channels` and `premultiplied` (indicating if premultiplication was used).
  * When using a crop strategy also contains `cropOffsetLeft` and `cropOffsetTop`.
+ * Animated output will also contain `pageHeight` and `pages`.
  * May also contain `textAutofitDpi` (dpi the font was rendered at) if image was created from text.
  *
  * A `Promise` is returned when `callback` is not provided.

src/pipeline.cc

@@ -849,6 +849,11 @@ class PipelineWorker : public Napi::AsyncWorker {
       image = sharp::SetAnimationProperties(
         image, nPages, targetPageHeight, baton->delay, baton->loop);
 
+      if (image.get_typeof(VIPS_META_PAGE_HEIGHT) == G_TYPE_INT) {
+        baton->pageHeightOut = image.get_int(VIPS_META_PAGE_HEIGHT);
+        baton->pagesOut = image.get_int(VIPS_META_N_PAGES);
+      }
+
       // Output
       sharp::SetTimeout(image, baton->timeoutSeconds);
       if (baton->fileOut.empty()) {
@@ -1284,6 +1289,10 @@ class PipelineWorker : public Napi::AsyncWorker {
       if (baton->input->textAutofitDpi) {
         info.Set("textAutofitDpi", static_cast<uint32_t>(baton->input->textAutofitDpi));
       }
+      if (baton->pageHeightOut) {
+        info.Set("pageHeight", static_cast<int32_t>(baton->pageHeightOut));
+        info.Set("pages", static_cast<int32_t>(baton->pagesOut));
+      }
 
       if (baton->bufferOutLength > 0) {
         // Add buffer size to info

src/pipeline.h

@@ -43,6 +43,8 @@ struct PipelineBaton {
   std::string fileOut;
   void *bufferOut;
   size_t bufferOutLength;
+  int pageHeightOut;
+  int pagesOut;
   std::vector<Composite *> composite;
   std::vector<sharp::InputDescriptor *> joinChannelIn;
   int topOffsetPre;
@@ -226,6 +228,8 @@ struct PipelineBaton {
   PipelineBaton():
     input(nullptr),
     bufferOutLength(0),
+    pageHeightOut(0),
+    pagesOut(0),
     topOffsetPre(-1),
     topOffsetPost(-1),
     channels(0),

test/unit/gif.js

@@ -39,7 +39,7 @@ describe('GIF input', () => {
       })
   );
 
-  it('Animated GIF first page to PNG', () =>
+  it('Animated GIF first page to non-animated GIF', () =>
     sharp(fixtures.inputGifAnimated)
       .toBuffer({ resolveWithObject: true })
       .then(({ data, info }) => {
@@ -49,10 +49,12 @@ describe('GIF input', () => {
         assert.strictEqual(80, info.width);
         assert.strictEqual(80, info.height);
         assert.strictEqual(4, info.channels);
+        assert.strictEqual(undefined, info.pages);
+        assert.strictEqual(undefined, info.pageHeight);
       })
   );
 
-  it('Animated GIF all pages to PNG "toilet roll"', () =>
+  it('Animated GIF round trip', () =>
     sharp(fixtures.inputGifAnimated, { pages: -1 })
       .toBuffer({ resolveWithObject: true })
       .then(({ data, info }) => {
@@ -62,6 +64,8 @@ describe('GIF input', () => {
         assert.strictEqual(80, info.width);
         assert.strictEqual(2400, info.height);
         assert.strictEqual(4, info.channels);
+        assert.strictEqual(30, info.pages);
+        assert.strictEqual(80, info.pageHeight);
       })
   );