Add support for (animated) GIFs

Gemfile.lock

@@ -33,7 +33,7 @@ GEM
       mime-types-data (~> 3.2015)
     mime-types-data (3.2016.0521)
     minitest (5.11.3)
-    rmagick (2.16.0)
+    rmagick (4.2.1)
     rspec (3.5.0)
       rspec-core (~> 3.5.0)
       rspec-expectations (~> 3.5.0)
@@ -67,4 +67,4 @@ DEPENDENCIES
   sqlite3
 
 BUNDLED WITH
-   1.16.1
+   1.17.3

README.md

@@ -20,9 +20,6 @@ If you are using bundler, add this to your Gemfile:
 
     gem 'carrierwave-vips'
 
-You will need to install the `rmagick` gem if you want to load GIF files. Writing GIFs is not supported by ruby-vips or this library.
-
-
 A quick overview
 ---------------------
 

lib/carrierwave/vips.rb

@@ -8,7 +8,7 @@ def self.configure
         c = Struct.new(:sharpen_mask, :sharpen_scale, :allowed_formats).new
         c.sharpen_mask = [ [ -1, -1, -1 ], [ -1, 24, -1 ], [ -1, -1, -1 ] ]
         c.sharpen_scale = 16
-        c.allowed_formats = %w(jpeg jpg png)
+        c.allowed_formats = %w(jpeg jpg png gif)
         c
       end
       @config
@@ -129,7 +129,7 @@ def convert(f, opts = {})
     #
     def resize_to_fit(new_width, new_height)
       manipulate! do |image|
-        resize_image(image,new_width,new_height)
+        resize_image(image, new_width, new_height)
       end
     end
 
@@ -146,27 +146,20 @@ def resize_to_fit(new_width, new_height)
     #
     def resize_to_fill(new_width, new_height)
       manipulate! do |image|
-
-        image = resize_image image, new_width, new_height, :max
-
-        if image.width > new_width
-          top = 0
-          left = (image.width - new_width) / 2
-        elsif image.height > new_height
-          left = 0
-          top = (image.height - new_height) / 2
+        if gif?
+          page_height = image.get 'page-height'
+          frame_count = image.height / page_height
+          frames = frame_count.times.map do |i|
+            frame = image.crop(0, i * page_height, image.width, page_height)
+            _resize_to_fill(frame, new_width, new_height)
+          end
+          new_image = ::Vips::Image.arrayjoin(frames, across: 1)
+          new_image.set('page-height', new_height)
+
+          new_image
         else
-          left = 0
-          top = 0
+          _resize_to_fill(image, new_width, new_height)
         end
-
-        # Floating point errors can sometimes chop off an extra pixel
-        # TODO: fix all the universe so that floating point errors never happen again
-        new_height = image.height if image.height < new_height
-        new_width = image.width if image.width < new_width
-
-        image.extract_area(left, top, new_width, new_height)
-
       end
     end
 
@@ -183,7 +176,8 @@ def resize_to_fill(new_width, new_height)
     #
     def resize_to_limit(new_width, new_height)
       manipulate! do |image|
-        image = resize_image(image,new_width,new_height) if new_width < image.width || new_height < image.height
+        ratio = get_ratio image, new_width, new_height, :min
+        image = resize_image(image, new_width, new_height) if ratio < 1
         image
       end
     end
@@ -244,6 +238,8 @@ def get_image
       cache_stored_file! unless cached?
       @_vimage ||= if jpeg? || png?
                      ::Vips::Image.new_from_file(current_path, access: :sequential)
+                   elsif gif?
+                     ::Vips::Image.new_from_file(current_path, n: -1)
                    else
                      ::Vips::Image.new_from_file(current_path)
                    end
@@ -254,20 +250,74 @@ def write_opts
     end
 
     def resize_image(image, width, height, min_or_max = :min)
+      if gif?
+        page_height = image.get 'page-height'
+        frame_count = image.height / page_height
+        frames = frame_count.times.map do |i|
+          frame = image.crop(0, i * page_height, image.width, page_height)
+          _resize_image(frame, width, height, min_or_max)
+        end
+
+        new_image = ::Vips::Image.arrayjoin(frames, across: 1)
+        ratio = get_ratio image, width, height, min_or_max
+        new_image.set('page-height', (page_height * ratio).round)
+
+        new_image
+      else
+        _resize_image(image, width, height, min_or_max)
+      end
+    end
+
+    def _resize_image(image, width, height, min_or_max = :min)
       ratio = get_ratio image, width, height, min_or_max
       return image if ratio == 1
       if ratio > 1
         image = image.resize(ratio, kernel: :nearest)
       else
         image = image.resize(ratio, kernel: :cubic)
-        image = image.conv(cwv_sharpen_mask) if cwv_config.sharpen_mask
+        image = image.conv(cwv_sharpen_mask) if cwv_config.sharpen_mask && !gif?
       end
       image
     end
 
-    def get_ratio(image, width,height, min_or_max = :min)
+    def _resize_to_fill(image, new_width, new_height)
+      image = _resize_image image, new_width, new_height, :max
+
+      if new_width && image.width > new_width
+        top = 0
+        left = (image.width - new_width) / 2
+      elsif new_height && image.height > new_height
+        left = 0
+        top = (image.height - new_height) / 2
+      else
+        left = 0
+        top = 0
+      end
+
+      # Floating point errors can sometimes chop off an extra pixel
+      # TODO: fix all the universe so that floating point errors never happen again
+      new_height = image.height if new_height.nil? || image.height < new_height
+      new_width = image.width if new_width.nil? || image.width < new_width
+
+      image.extract_area(left, top, new_width, new_height)
+    end
+
+    def get_image_height(image)
+      if gif?
+        image.get 'page-height'
+      else
+        image.height
+      end
+    end
+
+    def get_ratio(image, width, height, min_or_max = :min)
+      image_height = get_image_height image
+
+      return width.to_f / image.width if height.nil?
+      return height.to_f / image_height if width.nil?
+
       width_ratio = width.to_f / image.width
-      height_ratio = height.to_f / image.height
+      height_ratio = height.to_f / image_height
       [width_ratio, height_ratio].send(min_or_max)
     end
 
@@ -279,6 +329,10 @@ def png?(path = current_path)
       ext(path) == 'png'
     end
 
+    def gif?(path = current_path)
+      ext(path) == 'gif'
+    end
+
     def write_jpeg?(path)
       format_override == 'jpg' || jpeg?(path)
     end

spec/carrierwave/vips_spec.rb

@@ -19,7 +19,7 @@ class ImageUploader < CarrierWave::Uploader::Base
   include CarrierWave::Vips
 
   version :big_thumb do
-    process :resize_to_fill => [800,800]
+    process :resize_to_fill => [800, 800]
   end
 
   version :thumb do
@@ -38,30 +38,26 @@ class Dummy < ActiveRecord::Base
 
 
 describe CarrierWave::Vips do
-  
+
   let(:instance) { create_instance }
-  
+
   after do
-    Dir[file_path('*.copy.jpg')].each do |file|
+    Dir[file_path('*.copy.{jpg,gif}')].each do |file|
       FileUtils.rm(file)
     end
   end
 
   # Gotta figure out how to test this properly.
   it 'performs multiple operations properly'
 
-  describe "#convert" do
+  describe '#convert' do
 
     it 'converts from one format to another' do
       instance.convert('png')
       instance.process!
       expect(instance.filename).to match(/png$/)
     end
 
-    it 'throws an error on gif' do
-      expect { instance.convert('gif') }.to raise_error(ArgumentError)
-    end
-
     context 'when allowed formats are configured' do
       around do |example|
         original_formats = CarrierWave::Vips.configure.allowed_formats
@@ -90,51 +86,95 @@ class Dummy < ActiveRecord::Base
   end
 
   describe '#resize_to_fill' do
-    
+
     it 'resizes the image to exactly the given dimensions' do
-      instance.resize_to_fill(200,200)
+      instance.resize_to_fill(200, 200)
       instance.process!
       expect(instance).to have_dimensions(200, 200)
     end
 
-    it 'scales up the image if it smaller than the given dimensions' do
-      instance.resize_to_fill(1000,1000)
+    it 'scales up the image if it is smaller than the given dimensions' do
+      instance.resize_to_fill(1000, 1000)
       instance.process!
       expect(instance).to have_dimensions(1000, 1000)
     end
 
     it 'does not throw error on exact dimensions' do
-      instance.resize_to_fill(640,480)
+      instance.resize_to_fill(640, 480)
       instance.process!
-      expect(instance).to have_dimensions(640,480)
+      expect(instance).to have_dimensions(640, 480)
     end
 
     it 'recovers on floating point errors leading to overcrops' do
       instance = create_instance('wonky-resize.jpg')
-      instance.resize_to_fill(200,200)
+      instance.resize_to_fill(200, 200)
       instance.process!
     end
 
+    it 'accepts a nil value for width or height' do
+      instance.resize_to_fill(200, nil)
+      instance.process!
+      expect(instance).to have_dimensions(200, 150)
+    end
+
+    describe 'gif' do
+      let(:instance) { create_instance('ani.gif') }
+
+      it 'resizes the frames' do
+        instance.resize_to_fill(200, 200)
+        instance.process!
+        expect(instance).to have_dimensions(200, 200)
+      end
+
+      it 'scales up the image if it is smaller than the given dimensions' do
+        instance.resize_to_fill(960, 960)
+        instance.process!
+        expect(instance).to have_dimensions(960, 960)
+      end
+    end
+
   end
 
   describe '#resize_to_fit' do
-    
+
     it 'resizes the image to fit within the given dimensions' do
       instance.resize_to_fit(200, 200)
       instance.process!
       expect(instance).to have_dimensions(200, 150)
     end
 
-    it 'scales up the image if it smaller than the given dimensions' do
+    it 'scales up the image if it is smaller than the given dimensions' do
       instance.resize_to_fit(1000, 1000)
       instance.process!
       expect(instance).to have_dimensions(1000, 750)
     end
-
+
+    it 'accepts a nil value for width or height' do
+      instance.resize_to_fit(nil, 150)
+      instance.process!
+      expect(instance).to have_dimensions(200, 150)
+    end
+
+    describe 'gif' do
+      let(:instance) { create_instance('ani.gif') }
+
+      it 'resizes the frames' do
+        instance.resize_to_fit(240, 240)
+        instance.process!
+        expect(instance).to have_dimensions(240, 135)
+      end
+
+      it 'scales up the image if it is smaller than the given dimensions' do
+        instance.resize_to_fit(960, 960)
+        instance.process!
+        expect(instance).to have_dimensions(960, 540)
+      end
+    end
+
   end
 
   describe '#resize_to_limit' do
-    
+
     it 'resizes the image to fit within the given dimensions' do
       instance.resize_to_limit(200, 200)
       instance.process!
@@ -147,6 +187,28 @@ class Dummy < ActiveRecord::Base
       expect(instance).to have_dimensions(640, 480)
     end
 
+    it 'accepts a nil value for width or height' do
+      instance.resize_to_limit(200, nil)
+      instance.process!
+      expect(instance).to have_dimensions(200, 150)
+    end
+
+    describe 'gif' do
+      let(:instance) { create_instance('ani.gif') }
+
+      it 'resizes the frames' do
+        instance.resize_to_limit(200, 200)
+        instance.process!
+        expect(instance).to have_dimensions(200, 113)
+      end
+
+      it 'does not scale up the image if it is smaller than the given dimensions' do
+        instance.resize_to_limit(1000, 1000)
+        instance.process!
+        expect(instance).to have_dimensions(480, 270)
+      end
+    end
+
   end
 
   describe '#strip' do