Fix #5065: .webp images upload support

Add ability to upload .webp images.

Animated WebP images aren't supported. This is because they aren't
supported by FFmpeg yet[1], so generating thumbnails and samples for
them would be more complicated than for other formats.

[1]: https://trac.ffmpeg.org/ticket/4907

app/logical/exif_tool.rb

@@ -48,7 +48,7 @@ class ExifTool
     end
 
     def is_animated?
-      frame_count.to_i > 1 || is_animated_avif?
+      frame_count.to_i > 1 || is_animated_webp? || is_animated_avif?
     end
 
     def is_animated_gif?
@@ -59,6 +59,10 @@ class ExifTool
       file_ext == :png && is_animated?
     end
 
+    def is_animated_webp?
+      file_ext == :webp && metadata["RIFF:Duration"].present?
+    end
+
     def is_animated_avif?
       file_ext == :avif && metadata["QuickTime:CompatibleBrands"].to_a.include?("avis")
     end
@@ -123,8 +127,10 @@ class ExifTool
     def loop_count
       return Float::INFINITY if metadata["GIF:AnimationIterations"] == "Infinite"
       return Float::INFINITY if metadata["PNG:AnimationPlays"] == "inf"
+      return Float::INFINITY if metadata["RIFF:AnimationLoopCount"] == "inf"
       return metadata["GIF:AnimationIterations"] if has_key?("GIF:AnimationIterations")
       return metadata["PNG:AnimationPlays"] if has_key?("PNG:AnimationPlays")
+      return metadata["RIFF:AnimationLoopCount"] if has_key?("RIFF:AnimationLoopCount")
 
       # If the AnimationIterations tag isn't present, then it's counted as a loop count of 0.
       return 0 if is_animated_gif? && !has_key?("GIF:AnimationIterations")
@@ -153,6 +159,8 @@ class ExifTool
         :avif
       elsif has_key?("QuickTime:MovieHeaderVersion")
         :mp4
+      elsif keys.grep(/\ARIFF:/).any?
+        :webp
       elsif has_key?("Matroska:DocType")
         :webm
       elsif has_key?("Flash:FlashVersion")

app/logical/media_file.rb

@@ -26,7 +26,7 @@ class MediaFile
     file = Kernel.open(file, "r", binmode: true) unless file.respond_to?(:read)
 
     case file_ext(file)
-    when :jpg, :gif, :png, :avif
+    when :jpg, :gif, :png, :webp, :avif
       MediaFile::Image.new(file, **options)
     when :swf
       MediaFile::Flash.new(file, **options)
@@ -62,6 +62,10 @@ class MediaFile
     when /\A\x1a\x45\xdf\xa3/n
       :webm
 
+    # https://developers.google.com/speed/webp/docs/riff_container
+    when /\ARIFF....WEBP/
+      :webp
+
     # https://www.ftyps.com
     # isom (common) - MP4 Base Media v1 [IS0 14496-12:2003]
     # mp42 (common) - MP4 v2 [ISO 14496-14]
@@ -144,7 +148,7 @@ class MediaFile
 
   # @return [Boolean] true if the file is an image
   def is_image?
-    file_ext.in?([:jpg, :png, :gif, :avif])
+    file_ext.in?(%i[jpg png gif webp avif])
   end
 
   # @return [Boolean] true if the file is a video

app/logical/media_file/image.rb

@@ -16,6 +16,8 @@ class MediaFile::Image < MediaFile
     when :avif
       # XXX Mirrored AVIFs should be unsupported too, but we currently can't detect the mirrored flag using exiftool or ffprobe.
       !metadata.is_rotated? && !metadata.is_cropped? && !metadata.is_grid_image? && !metadata.is_animated_avif?
+    when :webp
+      !is_animated?
     else
       true
     end
@@ -34,11 +36,12 @@ class MediaFile::Image < MediaFile
   end
 
   def frame_count
-    if file_ext == :gif
-      image.get("n-pages")
-    elsif file_ext == :png
+    case file_ext
+    when :gif, :webp
+      image.get("n-pages") if image.get_fields.include?("n-pages")
+    when :png
       metadata.fetch("PNG:AnimationFrames", 1)
-    elsif file_ext == :avif
+    when :avif
       video.frame_count
     else
       nil
@@ -124,6 +127,10 @@ class MediaFile::Image < MediaFile
     file_ext == :png && is_animated?
   end
 
+  def is_animated_webp?
+    file_ext == :webp && is_animated?
+  end
+
   def is_animated_avif?
     file_ext == :avif && is_animated?
   end

app/models/media_asset.rb

@@ -3,7 +3,7 @@
 class MediaAsset < ApplicationRecord
   class Error < StandardError; end
 
-  FILE_TYPES = %w[jpg png gif avif mp4 webm swf zip]
+  FILE_TYPES = %w[jpg png gif webp avif mp4 webm swf zip]
   FILE_KEY_LENGTH = 9
   VARIANTS = %i[preview 180x180 360x360 720x720 sample original]
   MAX_FILE_SIZE = Danbooru.config.max_file_size.to_i
@@ -372,7 +372,7 @@ class MediaAsset < ApplicationRecord
 
   concerning :FileTypeMethods do
     def is_image?
-      file_ext.in?(%w[jpg png gif avif])
+      file_ext.in?(%w[jpg png gif webp avif])
     end
 
     def is_static_image?

app/models/post.rb

@@ -188,7 +188,7 @@ class Post < ApplicationRecord
     end
 
     def is_image?
-      file_ext =~ /jpg|gif|png|avif/i
+      file_ext =~ /jpg|gif|png|webp|avif/i
     end
 
     def is_flash?

test/files/webp/README.md

@@ -0,0 +1,6 @@
+Test file sources:
+
+* https://github.com/webmproject/libwebp-test-data
+* https://developers.google.com/speed/webp/gallery1
+* https://zpl.fi/exif-orientation-in-different-formats/
+* https://git.zpl.fi/exif-orientation/about/

test/functional/uploads_controller_test.rb

@@ -197,6 +197,13 @@ class UploadsControllerTest < ActionDispatch::IntegrationTest
         end
       end
 
+      context "for an unsupported WebP file" do
+        should "fail for an animated WebP" do
+          create_upload!("test/files/webp/nyancat.webp", user: @user)
+          assert_match("File type is not supported", Upload.last.error)
+        end
+      end
+
       context "for an unsupported AVIF file" do
         should "fail for a grid image" do
           create_upload!("test/files/avif/Image grid example.avif", user: @user)
@@ -309,6 +316,9 @@ class UploadsControllerTest < ActionDispatch::IntegrationTest
         should_upload_successfully("test/files/avif/hdr_cosmos01000_cicp9-16-9_yuv444_full_qp40.avif")
         should_upload_successfully("test/files/avif/paris_icc_exif_xmp.avif")
         should_upload_successfully("test/files/avif/tiger_3layer_1res.avif")
+
+        should_upload_successfully("test/files/webp/test.webp")
+        should_upload_successfully("test/files/webp/fjord.webp")
       end
 
       context "uploading multiple files from your computer" do

test/unit/autocomplete_service_test.rb

@@ -170,7 +170,7 @@ class AutocompleteServiceTest < ActiveSupport::TestCase
         assert_autocomplete_equals(["filetype:gif"], "filetype:g", :tag_query)
         assert_autocomplete_equals(["filetype:swf"], "filetype:s", :tag_query)
         assert_autocomplete_equals(["filetype:zip"], "filetype:z", :tag_query)
-        assert_autocomplete_equals(["filetype:webm"], "filetype:w", :tag_query)
+        assert_autocomplete_equals(["filetype:webm", "filetype:webp"], "filetype:w", :tag_query)
         assert_autocomplete_equals(["filetype:mp4"], "filetype:m", :tag_query)
 
         assert_autocomplete_equals(["commentary:true"], "commentary:tru", :tag_query)

test/unit/media_file_test.rb

@@ -21,6 +21,10 @@ class MediaFileTest < ActiveSupport::TestCase
       assert_equal([32, 32], MediaFile.open("test/files/test-static-32x32.gif").dimensions)
     end
 
+    should "determine the correct dimensions for a WebP file" do
+      assert_equal([550, 368], MediaFile.open("test/files/webp/fjord.webp").dimensions)
+    end
+
     should "determine the correct dimensions for an AVIF file" do
       assert_equal([2048, 858], MediaFile.open("test/files/avif/hdr_cosmos01000_cicp9-16-9_yuv420_limited_qp40.avif").dimensions)
     end
@@ -89,6 +93,12 @@ class MediaFileTest < ActiveSupport::TestCase
       assert_equal(:gif, MediaFile.open("test/files/test-static-32x32.gif").file_ext)
     end
 
+    should "determine the correct extension for a WebP file" do
+      Dir["test/files/webp/*.webp"].each do |file|
+        assert_equal(:webp, MediaFile.open(file).file_ext)
+      end
+    end
+
     should "determine the correct extension for an AVIF file" do
       Dir["test/files/avif/*.avif"].each do |file|
         assert_equal(:avif, MediaFile.open(file).file_ext)
@@ -137,6 +147,7 @@ class MediaFileTest < ActiveSupport::TestCase
       assert_equal([150, 101], MediaFile.open("test/files/test.jpg").preview(150, 150).dimensions)
       assert_equal([113, 150], MediaFile.open("test/files/test.png").preview(150, 150).dimensions)
       assert_equal([150, 150], MediaFile.open("test/files/test.gif").preview(150, 150).dimensions)
+      assert_equal([150, 100], MediaFile.open("test/files/webp/fjord.webp").preview(150, 150).dimensions)
       assert_equal([150, 63], MediaFile.open("test/files/avif/hdr_cosmos01000_cicp9-16-9_yuv420_limited_qp40.avif").preview(150, 150).dimensions)
     end
 
@@ -311,6 +322,40 @@ class MediaFileTest < ActiveSupport::TestCase
     end
   end
 
+  context "a WebP file" do
+    should "be able to read WebP files" do
+      Dir["test/files/webp/*.webp"].each do |file|
+        assert_nothing_raised { MediaFile.open(file).attributes }
+      end
+    end
+
+    should "detect animated files" do
+      assert_equal(true, MediaFile.open("test/files/webp/nyancat.webp").is_animated?)
+      assert_equal(true, MediaFile.open("test/files/webp/nyancat.webp").is_animated_webp?)
+      assert_equal(true, MediaFile.open("test/files/webp/nyancat.webp").metadata.is_animated?)
+      assert_equal(false, MediaFile.open("test/files/webp/nyancat.webp").is_supported?)
+      assert_equal(12, MediaFile.open("test/files/webp/nyancat.webp").frame_count)
+      assert_equal(Float::INFINITY, MediaFile.open("test/files/webp/nyancat.webp").metadata.loop_count)
+
+      # assert_equal(0.84, MediaFile.open("test/files/webp/nyancat.webp").duration)
+    end
+
+    should "be able to generate a preview" do
+      assert_equal([128, 128], MediaFile.open("test/files/webp/test.webp").preview(180, 180).dimensions)
+      assert_equal([176, 180], MediaFile.open("test/files/webp/2_webp_a.webp").preview(180, 180).dimensions)
+      assert_equal([176, 180], MediaFile.open("test/files/webp/2_webp_ll.webp").preview(180, 180).dimensions)
+      assert_equal([180, 120], MediaFile.open("test/files/webp/Exif2.webp").preview(180, 180).dimensions)
+      assert_equal([180, 120], MediaFile.open("test/files/webp/fjord.webp").preview(180, 180).dimensions)
+      assert_equal([180,  55], MediaFile.open("test/files/webp/lossless1.webp").preview(180, 180).dimensions)
+      assert_equal([180,  55], MediaFile.open("test/files/webp/lossy_alpha1.webp").preview(180, 180).dimensions)
+    end
+
+    should "ignore EXIF orientation tags" do
+      # XXX It's possible for .webp files to contain the IFD0:Orientation tag, but browsers currently ignore it, so we do too.
+      assert_equal(false, MediaFile.open("test/files/webp/Exif2.webp").metadata.is_rotated?)
+    end
+  end
+
   context "an AVIF file" do
     should "be able to read AVIF files" do
       Dir["test/files/avif/*.avif"].each do |file|