VideoPlayer: Create application to parse (and eventually play) videos

This application will eventually be able to actually play videos, but
for now it is used to parse and dump decoded data from the VP9 decoder.

Userland/Applications/CMakeLists.txt

@@ -28,4 +28,5 @@ add_subdirectory(SystemMonitor)
 add_subdirectory(ThemeEditor)
 add_subdirectory(Terminal)
 add_subdirectory(TextEditor)
+add_subdirectory(VideoPlayer)
 add_subdirectory(Welcome)

Userland/Applications/VideoPlayer/CMakeLists.txt

@@ -0,0 +1,6 @@
+set(SOURCES
+    main.cpp
+)
+
+serenity_bin(VideoPlayer)
+target_link_libraries(VideoPlayer LibVideo LibAudio LibGUI)

Userland/Applications/VideoPlayer/main.cpp

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2021, Hunter Salyer <thefalsehonesty@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibAudio/ClientConnection.h>
+#include <LibCore/EventLoop.h>
+#include <LibGUI/Application.h>
+#include <LibGUI/BoxLayout.h>
+#include <LibGUI/ImageWidget.h>
+#include <LibGUI/Window.h>
+#include <LibGfx/Bitmap.h>
+#include <LibVideo/MatroskaReader.h>
+#include <LibVideo/VP9/Decoder.h>
+
+int main(int argc, char** argv)
+{
+    auto app = GUI::Application::construct(argc, argv);
+    auto window = GUI::Window::construct();
+
+    auto document = Video::MatroskaReader::parse_matroska_from_file("/home/anon/Videos/test-webm.webm");
+    const auto& optional_track = document->track_for_track_type(Video::TrackEntry::TrackType::Video);
+    if (!optional_track.has_value())
+        return 1;
+    const auto& track = optional_track.value();
+    const auto video_track = track.video_track().value();
+
+    auto image = Gfx::Bitmap::create(Gfx::BitmapFormat::BGRx8888, Gfx::IntSize(video_track.pixel_height, video_track.pixel_width));
+    auto& main_widget = window->set_main_widget<GUI::Widget>();
+    main_widget.set_fill_with_background_color(true);
+    main_widget.set_layout<GUI::VerticalBoxLayout>();
+    auto& image_widget = main_widget.add<GUI::ImageWidget>();
+    image_widget.set_bitmap(image);
+    image_widget.set_fixed_size(video_track.pixel_height, video_track.pixel_width);
+    main_widget.add_child(image_widget);
+
+    Video::VP9::Decoder vp9_decoder;
+    for (const auto& cluster : document->clusters()) {
+        for (const auto& block : cluster.blocks()) {
+            if (block.track_number() != track.track_number())
+                continue;
+
+            const auto& frame = block.frame(0);
+            dbgln("Reading frame 0 from block @ {}", block.timestamp());
+            vp9_decoder.parse_frame(frame);
+            vp9_decoder.dump_info();
+        }
+    }
+
+    window->show();
+    return app->exec();
+}