From 3c5450b8beb01b19a54dbc70080e1373bd7d57b7 Mon Sep 17 00:00:00 2001
From: Nico Weber <thakis@chromium.org>
Date: Sat, 25 Feb 2023 22:15:34 -0500
Subject: [PATCH] LibGfx: Implement is_animated() and frame_count() for webp
 plugin

---
 Tests/LibGfx/TestImageDecoder.cpp        |  7 ++++---
 Userland/Libraries/LibGfx/WebPLoader.cpp | 22 ++++++++++++++++++----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/Tests/LibGfx/TestImageDecoder.cpp b/Tests/LibGfx/TestImageDecoder.cpp
index f7b8d6dd62..97ff6a4aac 100644
--- a/Tests/LibGfx/TestImageDecoder.cpp
+++ b/Tests/LibGfx/TestImageDecoder.cpp
@@ -284,9 +284,10 @@ TEST_CASE(test_webp_extended_lossless_animated)
     auto plugin_decoder = MUST(Gfx::WebPImageDecoderPlugin::create(file->bytes()));
     EXPECT(plugin_decoder->initialize());
 
-    // FIXME: These three lines are wrong.
-    EXPECT_EQ(plugin_decoder->frame_count(), 1u);
-    EXPECT(!plugin_decoder->is_animated());
+    EXPECT_EQ(plugin_decoder->frame_count(), 8u);
+    EXPECT(plugin_decoder->is_animated());
+
+    // FIXME: This is wrong.
     EXPECT(!plugin_decoder->loop_count());
 
     EXPECT_EQ(plugin_decoder->size(), Gfx::IntSize(990, 1050));
diff --git a/Userland/Libraries/LibGfx/WebPLoader.cpp b/Userland/Libraries/LibGfx/WebPLoader.cpp
index 646b6efb42..93a40361ae 100644
--- a/Userland/Libraries/LibGfx/WebPLoader.cpp
+++ b/Userland/Libraries/LibGfx/WebPLoader.cpp
@@ -519,8 +519,15 @@ ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> WebPImageDecoderPlugin::create(Readon
 
 bool WebPImageDecoderPlugin::is_animated()
 {
-    // FIXME
-    return false;
+    if (m_context->state == WebPLoadingContext::State::Error)
+        return false;
+
+    if (m_context->state < WebPLoadingContext::State::FirstChunkDecoded) {
+        if (decode_webp_first_chunk(*m_context).is_error())
+            return false;
+    }
+
+    return m_context->first_chunk->type == FourCC("VP8X") && m_context->vp8x_header.has_animation;
 }
 
 size_t WebPImageDecoderPlugin::loop_count()
@@ -531,8 +538,15 @@ size_t WebPImageDecoderPlugin::loop_count()
 
 size_t WebPImageDecoderPlugin::frame_count()
 {
-    // FIXME
-    return 1;
+    if (!is_animated())
+        return 1;
+
+    if (m_context->state < WebPLoadingContext::State::ChunksDecoded) {
+        if (decode_webp_chunks(*m_context).is_error())
+            return 1;
+    }
+
+    return m_context->animation_frame_chunks.size();
 }
 
 ErrorOr<ImageFrameDescriptor> WebPImageDecoderPlugin::frame(size_t index)