core: Add video dumper interface

The VideoFrame is rotated while copying, to put the pixels in their correct positions (OpenGL seems to return the image in reverted order by default)

src/core/CMakeLists.txt

@@ -36,6 +36,8 @@ add_library(core STATIC
     core.h
     core_timing.cpp
     core_timing.h
+    dumping/backend.cpp
+    dumping/backend.h
     file_sys/archive_backend.cpp
     file_sys/archive_backend.h
     file_sys/archive_extsavedata.cpp

src/core/dumping/backend.cpp

@@ -0,0 +1,26 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstring>
+#include "core/dumping/backend.h"
+
+namespace VideoDumper {
+
+VideoFrame::VideoFrame(std::size_t width_, std::size_t height_, u8* data_)
+    : width(width_), height(height_), stride(width * 4), data(width * height * 4) {
+    // While copying, rotate the image to put the pixels in correct order
+    // (As OpenGL returns pixel data starting from the lowest position)
+    for (std::size_t i = 0; i < height; i++) {
+        for (std::size_t j = 0; j < width; j++) {
+            for (std::size_t k = 0; k < 4; k++) {
+                data[i * stride + j * 4 + k] = data_[(height - i - 1) * stride + j * 4 + k];
+            }
+        }
+    }
+}
+
+Backend::~Backend() = default;
+NullBackend::~NullBackend() = default;
+
+} // namespace VideoDumper

src/core/dumping/backend.h

@@ -0,0 +1,59 @@
+// Copyright 2018 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <string>
+#include <vector>
+#include "audio_core/audio_types.h"
+#include "common/common_types.h"
+#include "core/frontend/framebuffer_layout.h"
+
+namespace VideoDumper {
+/**
+ * Frame dump data for a single screen
+ * data is in RGB888 format, left to right then top to bottom
+ */
+class VideoFrame {
+public:
+    std::size_t width;
+    std::size_t height;
+    u32 stride;
+    std::vector<u8> data;
+
+    VideoFrame(std::size_t width_ = 0, std::size_t height_ = 0, u8* data_ = nullptr);
+};
+
+class Backend {
+public:
+    virtual ~Backend();
+    virtual bool StartDumping(const std::string& path, const std::string& format,
+                              const Layout::FramebufferLayout& layout) = 0;
+    virtual void AddVideoFrame(const VideoFrame& frame) = 0;
+    virtual void AddAudioFrame(const AudioCore::StereoFrame16& frame) = 0;
+    virtual void AddAudioSample(const std::array<s16, 2>& sample) = 0;
+    virtual void StopDumping() = 0;
+    virtual bool IsDumping() const = 0;
+    virtual Layout::FramebufferLayout GetLayout() const = 0;
+};
+
+class NullBackend : public Backend {
+public:
+    ~NullBackend() override;
+    bool StartDumping(const std::string& /*path*/, const std::string& /*format*/,
+                      const Layout::FramebufferLayout& /*layout*/) override {
+        return false;
+    }
+    void AddVideoFrame(const VideoFrame& /*frame*/) override {}
+    void AddAudioFrame(const AudioCore::StereoFrame16& /*frame*/) override {}
+    void AddAudioSample(const std::array<s16, 2>& /*sample*/) override {}
+    void StopDumping() override {}
+    bool IsDumping() const override {
+        return false;
+    }
+    Layout::FramebufferLayout GetLayout() const override {
+        return Layout::FramebufferLayout{};
+    }
+};
+} // namespace VideoDumper