LibVideo: Add test to ensure that a VP9 WebM file will decode

This will test decoding of one second of video, to ensure that it can
fully decode the entire file.

Tests/CMakeLists.txt

@@ -21,6 +21,7 @@ add_subdirectory(LibTextCodec)
 add_subdirectory(LibThreading)
 add_subdirectory(LibTimeZone)
 add_subdirectory(LibUnicode)
+add_subdirectory(LibVideo)
 add_subdirectory(LibWasm)
 add_subdirectory(LibWeb)
 add_subdirectory(LibXML)

Tests/LibVideo/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(TEST_SOURCES
+    TestVP9Decode.cpp
+)
+
+foreach(source IN LISTS TEST_SOURCES)
+    serenity_test("${source}" LibVideo LIBS LibVideo)
+endforeach()
+
+install(FILES vp9_in_webm.webm DESTINATION usr/Tests/LibVideo)

Tests/LibVideo/TestVP9Decode.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2022, Gregory Bertilson <zaggy1024@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <LibVideo/MatroskaReader.h>
+#include <LibVideo/VP9/Decoder.h>
+
+TEST_CASE(webm_in_vp9)
+{
+    auto matroska_document = Video::MatroskaReader::MatroskaReader::parse_matroska_from_file("./vp9_in_webm.webm"sv);
+    VERIFY(matroska_document);
+    auto video_track_optional = matroska_document->track_for_track_type(Video::TrackEntry::TrackType::Video);
+    VERIFY(video_track_optional.has_value());
+    auto video_track_entry = video_track_optional.value();
+
+    size_t cluster_index, block_index, frame_index;
+    Video::VP9::Decoder vp9_decoder;
+
+    for (cluster_index = 0; cluster_index < matroska_document->clusters().size(); cluster_index++) {
+        auto const& cluster = matroska_document->clusters()[cluster_index];
+        for (block_index = 0; block_index < cluster.blocks().size(); block_index++) {
+            auto const& block = cluster.blocks()[block_index];
+            if (block.track_number() != video_track_entry.track_number())
+                continue;
+
+            for (frame_index = 0; frame_index < block.frames().size(); frame_index++) {
+                MUST(vp9_decoder.decode(block.frames()[frame_index]));
+            }
+        }
+    }
+
+    VERIFY(cluster_index == 1 && block_index == 25 && frame_index == 1);
+}