Merge pull request #13046 from SuperSamus/vi-overclock

Add VBI Frequency Override

16 files changed, 156 insertions, 16 deletions

diff --git a/Source/Core/Core/Config/MainSettings.cpp b/Source/Core/Core/Config/MainSettings.cpp
index 9f4d1cce17..0b6a2fd6c1 100644
--- a/Source/Core/Core/Config/MainSettings.cpp
+++ b/Source/Core/Core/Config/MainSettings.cpp
@@ -222,6 +222,8 @@ const Info<bool> MAIN_PRECISION_FRAME_TIMING{{System::Main, "Core", "PrecisionFr
                                              DEFAULT_PRECISION_FRAME_TIMING};
 const Info<float> MAIN_OVERCLOCK{{System::Main, "Core", "Overclock"}, 1.0f};
 const Info<bool> MAIN_OVERCLOCK_ENABLE{{System::Main, "Core", "OverclockEnable"}, false};
+const Info<float> MAIN_VI_OVERCLOCK{{System::Main, "Core", "VIOverclock"}, 1.0f};
+const Info<bool> MAIN_VI_OVERCLOCK_ENABLE{{System::Main, "Core", "VIOverclockEnable"}, false};
 const Info<bool> MAIN_RAM_OVERRIDE_ENABLE{{System::Main, "Core", "RAMOverrideEnable"}, false};
 const Info<u32> MAIN_MEM1_SIZE{{System::Main, "Core", "MEM1Size"}, Memory::MEM1_SIZE_RETAIL};
 const Info<u32> MAIN_MEM2_SIZE{{System::Main, "Core", "MEM2Size"}, Memory::MEM2_SIZE_RETAIL};
diff --git a/Source/Core/Core/Config/MainSettings.h b/Source/Core/Core/Config/MainSettings.h
index 28a044d253..774824e450 100644
--- a/Source/Core/Core/Config/MainSettings.h
+++ b/Source/Core/Core/Config/MainSettings.h
@@ -128,6 +128,8 @@ extern const Info<float> MAIN_EMULATION_SPEED;
 extern const Info<bool> MAIN_PRECISION_FRAME_TIMING;
 extern const Info<float> MAIN_OVERCLOCK;
 extern const Info<bool> MAIN_OVERCLOCK_ENABLE;
+extern const Info<float> MAIN_VI_OVERCLOCK;
+extern const Info<bool> MAIN_VI_OVERCLOCK_ENABLE;
 extern const Info<bool> MAIN_RAM_OVERRIDE_ENABLE;
 extern const Info<u32> MAIN_MEM1_SIZE;
 extern const Info<u32> MAIN_MEM2_SIZE;
diff --git a/Source/Core/Core/ConfigLoaders/NetPlayConfigLoader.cpp b/Source/Core/Core/ConfigLoaders/NetPlayConfigLoader.cpp
index 5f772fd0e3..855cc181b9 100644
--- a/Source/Core/Core/ConfigLoaders/NetPlayConfigLoader.cpp
+++ b/Source/Core/Core/ConfigLoaders/NetPlayConfigLoader.cpp
@@ -42,6 +42,8 @@ public:
     layer->Set(Config::MAIN_DSP_HLE, m_settings.dsp_hle);
     layer->Set(Config::MAIN_OVERCLOCK_ENABLE, m_settings.oc_enable);
     layer->Set(Config::MAIN_OVERCLOCK, m_settings.oc_factor);
+    layer->Set(Config::MAIN_VI_OVERCLOCK_ENABLE, m_settings.vi_oc_enable);
+    layer->Set(Config::MAIN_VI_OVERCLOCK, m_settings.vi_oc_factor);
     for (ExpansionInterface::Slot slot : ExpansionInterface::SLOTS)
       layer->Set(Config::GetInfoForEXIDevice(slot), m_settings.exi_device[slot]);
     layer->Set(Config::MAIN_MEMORY_CARD_SIZE, m_settings.memcard_size_override);
diff --git a/Source/Core/Core/CoreTiming.cpp b/Source/Core/Core/CoreTiming.cpp
index 0de77f4446..f4c7d13fc0 100644
--- a/Source/Core/Core/CoreTiming.cpp
+++ b/Source/Core/Core/CoreTiming.cpp
@@ -119,7 +119,9 @@ void CoreTimingManager::Shutdown()
 void CoreTimingManager::RefreshConfig()
 {
   m_config_oc_factor =
-      Config::Get(Config::MAIN_OVERCLOCK_ENABLE) ? Config::Get(Config::MAIN_OVERCLOCK) : 1.0f;
+      (Config::Get(Config::MAIN_OVERCLOCK_ENABLE) ? Config::Get(Config::MAIN_OVERCLOCK) : 1.0f) *
+      (Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE) ? Config::Get(Config::MAIN_VI_OVERCLOCK) :
+                                                       1.0f);
   m_config_oc_inv_factor = 1.0f / m_config_oc_factor;
   m_config_sync_on_skip_idle = Config::Get(Config::MAIN_SYNC_ON_SKIP_IDLE);
 
@@ -482,6 +484,11 @@ bool CoreTimingManager::GetVISkip() const
   return m_throttle_disable_vi_int && g_ActiveConfig.bVISkip && !Core::WantsDeterminism();
 }
 
+float CoreTimingManager::GetOverclock() const
+{
+  return m_config_oc_factor;
+}
+
 bool CoreTimingManager::UseSyncOnSkipIdle() const
 {
   return m_config_sync_on_skip_idle;
diff --git a/Source/Core/Core/CoreTiming.h b/Source/Core/Core/CoreTiming.h
index d6f652c35a..ae0dccd38c 100644
--- a/Source/Core/Core/CoreTiming.h
+++ b/Source/Core/Core/CoreTiming.h
@@ -165,6 +165,8 @@ public:
   // Used by VideoInterface
   bool GetVISkip() const;
 
+  float GetOverclock() const;
+
   bool UseSyncOnSkipIdle() const;
 
 private:
diff --git a/Source/Core/Core/DolphinAnalytics.cpp b/Source/Core/Core/DolphinAnalytics.cpp
index 5613e3fea4..3551321e6f 100644
--- a/Source/Core/Core/DolphinAnalytics.cpp
+++ b/Source/Core/Core/DolphinAnalytics.cpp
@@ -365,6 +365,8 @@ void DolphinAnalytics::MakePerGameBuilder()
   builder.AddData("cfg-audio-backend", Config::Get(Config::MAIN_AUDIO_BACKEND));
   builder.AddData("cfg-oc-enable", Config::Get(Config::MAIN_OVERCLOCK_ENABLE));
   builder.AddData("cfg-oc-factor", Config::Get(Config::MAIN_OVERCLOCK));
+  builder.AddData("cfg-vi-oc-enable", Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE));
+  builder.AddData("cfg-vi-oc-factor", Config::Get(Config::MAIN_VI_OVERCLOCK));
   builder.AddData("cfg-render-to-main", Config::Get(Config::MAIN_RENDER_TO_MAIN));
   if (g_video_backend)
   {
diff --git a/Source/Core/Core/HW/VideoInterface.cpp b/Source/Core/Core/HW/VideoInterface.cpp
index b03a8c5988..e1e822f08e 100644
--- a/Source/Core/Core/HW/VideoInterface.cpp
+++ b/Source/Core/Core/HW/VideoInterface.cpp
@@ -13,8 +13,10 @@
 #include "Common/Config/Config.h"
 #include "Common/Logging/Log.h"
 
+#include "VideoCommon/OnScreenDisplay.h"
 #include "VideoCommon/PerformanceMetrics.h"
 
+#include "Core/AchievementManager.h"
 #include "Core/Config/GraphicsSettings.h"
 #include "Core/Config/MainSettings.h"
 #include "Core/Config/SYSCONFSettings.h"
@@ -41,7 +43,10 @@ VideoInterfaceManager::VideoInterfaceManager(Core::System& system) : m_system(sy
 {
 }
 
-VideoInterfaceManager::~VideoInterfaceManager() = default;
+VideoInterfaceManager::~VideoInterfaceManager()
+{
+  Config::RemoveConfigChangedCallback(m_config_changed_callback_id);
+}
 
 static constexpr std::array<u32, 2> CLOCK_FREQUENCIES{{
     27000000,
@@ -173,6 +178,22 @@ void VideoInterfaceManager::Preset(bool _bNTSC)
 void VideoInterfaceManager::Init()
 {
   Preset(true);
+
+  m_config_changed_callback_id = Config::AddConfigChangedCallback([this] { RefreshConfig(); });
+  RefreshConfig();
+}
+
+void VideoInterfaceManager::RefreshConfig()
+{
+  m_config_vi_oc_factor =
+      Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE) ? Config::Get(Config::MAIN_VI_OVERCLOCK) : 1.0f;
+  if (AchievementManager::GetInstance().IsHardcoreModeActive() && m_config_vi_oc_factor < 1.0f)
+  {
+    Config::SetCurrent(Config::MAIN_VI_OVERCLOCK, 1.0f);
+    m_config_vi_oc_factor = 1.0f;
+    OSD::AddMessage("Minimum VBI frequency is 100% in Hardcore Mode");
+  }
+  UpdateRefreshRate();
 }
 
 void VideoInterfaceManager::RegisterMMIO(MMIO::Mapping* mmio, u32 base)
@@ -488,7 +509,8 @@ float VideoInterfaceManager::GetAspectRatio() const
   float vertical_period = tick_length * GetTicksPerField();
   float horizontal_period = tick_length * GetTicksPerHalfLine() * 2;
   float vertical_active_area = active_lines * horizontal_period;
-  float horizontal_active_area = tick_length * GetTicksPerSample() * active_width_samples;
+  float horizontal_active_area =
+      tick_length * GetTicksPerSample() * active_width_samples / m_config_vi_oc_factor;
 
   // We are approximating the horizontal/vertical flyback transformers that control the
   // position of the electron beam on the screen. Our flyback transformers create a
@@ -707,7 +729,11 @@ void VideoInterfaceManager::UpdateParameters()
                           m_vblank_timing_even.PRB - odd_even_psb_diff;
   m_even_field_last_hl = m_even_field_first_hl + acv_hl - 1;
 
-  // Refresh rate:
+  UpdateRefreshRate();
+}
+
+void VideoInterfaceManager::UpdateRefreshRate()
+{
   m_target_refresh_rate_numerator = m_system.GetSystemTimers().GetTicksPerSecond() * 2;
   m_target_refresh_rate_denominator = GetTicksPerEvenField() + GetTicksPerOddField();
   m_target_refresh_rate =
@@ -736,7 +762,7 @@ u32 VideoInterfaceManager::GetTicksPerSample() const
 
 u32 VideoInterfaceManager::GetTicksPerHalfLine() const
 {
-  return GetTicksPerSample() * m_h_timing_0.HLW;
+  return GetTicksPerSample() * m_h_timing_0.HLW / m_config_vi_oc_factor;
 }
 
 u32 VideoInterfaceManager::GetTicksPerField() const
diff --git a/Source/Core/Core/HW/VideoInterface.h b/Source/Core/Core/HW/VideoInterface.h
index 8bb1e23405..e35bc42427 100644
--- a/Source/Core/Core/HW/VideoInterface.h
+++ b/Source/Core/Core/HW/VideoInterface.h
@@ -7,6 +7,7 @@
 #include <memory>
 
 #include "Common/CommonTypes.h"
+#include "Common/Config/Config.h"
 
 enum class FieldType;
 class PointerWrap;
@@ -407,6 +408,9 @@ private:
   void BeginField(FieldType field, u64 ticks);
   void EndField(FieldType field, u64 ticks);
 
+  void RefreshConfig();
+  void UpdateRefreshRate();
+
   // Registers listed in order:
   UVIVerticalTimingRegister m_vertical_timing_register;
   UVIDisplayControlRegister m_display_control_register;
@@ -447,6 +451,9 @@ private:
   u32 m_even_field_last_hl = 0;   // index last halfline of the even field
   u32 m_odd_field_last_hl = 0;    // index last halfline of the odd field
 
+  float m_config_vi_oc_factor = 0.0f;
+
+  Config::ConfigChangedCallbackID m_config_changed_callback_id;
   Core::System& m_system;
 };
 }  // namespace VideoInterface
diff --git a/Source/Core/Core/IOS/DolphinDevice.cpp b/Source/Core/Core/IOS/DolphinDevice.cpp
index 944bec41b2..c240b922b7 100644
--- a/Source/Core/Core/IOS/DolphinDevice.cpp
+++ b/Source/Core/Core/IOS/DolphinDevice.cpp
@@ -68,9 +68,7 @@ IPCReply GetCPUSpeed(Core::System& system, const IOCtlVRequest& request)
     return IPCReply(IPC_EINVAL);
   }
 
-  const bool overclock_enabled = Config::Get(Config::MAIN_OVERCLOCK_ENABLE);
-  const float oc = overclock_enabled ? Config::Get(Config::MAIN_OVERCLOCK) : 1.0f;
-
+  const bool oc = system.GetCoreTiming().GetOverclock();
   const u32 core_clock = u32(float(system.GetSystemTimers().GetTicksPerSecond()) * oc);
 
   auto& memory = system.GetMemory();
diff --git a/Source/Core/Core/NetPlayClient.cpp b/Source/Core/Core/NetPlayClient.cpp
index aee89cbc1c..d3568ae2d1 100644
--- a/Source/Core/Core/NetPlayClient.cpp
+++ b/Source/Core/Core/NetPlayClient.cpp
@@ -862,6 +862,8 @@ void NetPlayClient::OnStartGame(sf::Packet& packet)
     packet >> m_net_settings.allow_sd_writes;
     packet >> m_net_settings.oc_enable;
     packet >> m_net_settings.oc_factor;
+    packet >> m_net_settings.vi_oc_enable;
+    packet >> m_net_settings.vi_oc_factor;
 
     for (auto slot : ExpansionInterface::SLOTS)
       packet >> m_net_settings.exi_device[slot];
diff --git a/Source/Core/Core/NetPlayProto.h b/Source/Core/Core/NetPlayProto.h
index c97d04c2b2..62a9aba9a4 100644
--- a/Source/Core/Core/NetPlayProto.h
+++ b/Source/Core/Core/NetPlayProto.h
@@ -47,6 +47,8 @@ struct NetSettings
   bool allow_sd_writes = false;
   bool oc_enable = false;
   float oc_factor = 0;
+  bool vi_oc_enable = false;
+  float vi_oc_factor = 0;
   Common::EnumMap<ExpansionInterface::EXIDeviceType, ExpansionInterface::MAX_SLOT> exi_device{};
   int memcard_size_override = -1;
 
diff --git a/Source/Core/Core/NetPlayServer.cpp b/Source/Core/Core/NetPlayServer.cpp
index 4cff258e9b..51b3f1916b 100644
--- a/Source/Core/Core/NetPlayServer.cpp
+++ b/Source/Core/Core/NetPlayServer.cpp
@@ -1376,6 +1376,8 @@ bool NetPlayServer::SetupNetSettings()
   settings.allow_sd_writes = Config::Get(Config::MAIN_ALLOW_SD_WRITES);
   settings.oc_enable = Config::Get(Config::MAIN_OVERCLOCK_ENABLE);
   settings.oc_factor = Config::Get(Config::MAIN_OVERCLOCK);
+  settings.vi_oc_enable = Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE);
+  settings.vi_oc_factor = Config::Get(Config::MAIN_VI_OVERCLOCK);
 
   for (ExpansionInterface::Slot slot : ExpansionInterface::SLOTS)
   {
@@ -1603,6 +1605,8 @@ bool NetPlayServer::StartGame()
   spac << m_settings.allow_sd_writes;
   spac << m_settings.oc_enable;
   spac << m_settings.oc_factor;
+  spac << m_settings.vi_oc_enable;
+  spac << m_settings.vi_oc_factor;
 
   for (auto slot : ExpansionInterface::SLOTS)
     spac << static_cast<int>(m_settings.exi_device[slot]);
diff --git a/Source/Core/DolphinQt/Settings/AdvancedPane.cpp b/Source/Core/DolphinQt/Settings/AdvancedPane.cpp
index 917e7e898c..31e73a5b34 100644
--- a/Source/Core/DolphinQt/Settings/AdvancedPane.cpp
+++ b/Source/Core/DolphinQt/Settings/AdvancedPane.cpp
@@ -20,6 +20,7 @@
 #include "Core/ConfigManager.h"
 #include "Core/Core.h"
 #include "Core/HW/SystemTimers.h"
+#include "Core/HW/VideoInterface.h"
 #include "Core/PowerPC/PowerPC.h"
 #include "Core/System.h"
 
@@ -111,14 +112,47 @@ void AdvancedPane::CreateLayout()
 
   m_cpu_clock_override_checkbox->SetDescription(
       tr("Adjusts the emulated CPU's clock rate.<br><br>"
-         "Higher values may make variable-framerate games run at a higher framerate, "
-         "at the expense of performance. Lower values may activate a game's "
-         "internal frameskip, potentially improving performance.<br><br>"
-         "<b>WARNING</b>: Changing this from the default (100%) can and will "
+         "On games that have an unstable frame rate despite full emulation speed, "
+         "higher values can improve their performance, requiring a powerful device. "
+         "Lower values reduce the emulated console's performance, but improve the "
+         "emulation speed.<br><br>"
+         "WARNING: Changing this from the default (100%) can and will "
          "break games and cause glitches. Do so at your own risk. "
          "Please do not report bugs that occur with a non-default clock."
          "<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
 
+  auto* vi_rate_override = new QGroupBox(tr("VBI Frequency Override"));
+  auto* vi_rate_override_layout = new QVBoxLayout();
+  vi_rate_override->setLayout(vi_rate_override_layout);
+  main_layout->addWidget(vi_rate_override);
+
+  m_vi_rate_override_checkbox =
+      new ConfigBool(tr("Enable VBI Frequency Override"), Config::MAIN_VI_OVERCLOCK_ENABLE);
+  vi_rate_override_layout->addWidget(m_vi_rate_override_checkbox);
+  connect(m_vi_rate_override_checkbox, &QCheckBox::toggled, this, &AdvancedPane::Update);
+
+  auto* vi_rate_override_slider_layout = new QHBoxLayout();
+  vi_rate_override_slider_layout->setContentsMargins(0, 0, 0, 0);
+  vi_rate_override_layout->addLayout(vi_rate_override_slider_layout);
+
+  m_vi_rate_override_slider = new QSlider(Qt::Horizontal);
+  m_vi_rate_override_slider->setRange(1, 500);
+  vi_rate_override_slider_layout->addWidget(m_vi_rate_override_slider);
+
+  m_vi_rate_override_slider_label = new QLabel();
+  vi_rate_override_slider_layout->addWidget(m_vi_rate_override_slider_label);
+
+  m_vi_rate_override_checkbox->SetDescription(
+      tr("Adjusts the VBI frequency. Also adjusts the emulated CPU's "
+         "clock rate, to keep it relatively the same.<br><br>"
+         "Makes games run at a different frame rate, making the emulation less "
+         "demanding when lowered, or improving smoothness when increased. This may "
+         "affect gameplay speed, as it is often tied to the frame rate.<br><br>"
+         "WARNING: Changing this from the default (100%) can and will "
+         "break games and cause glitches. Do so at your own risk. "
+         "Please do not report bugs that occur with a non-default frequency."
+         "<br><br><dolphin_emphasis>If unsure, leave this unchecked.</dolphin_emphasis>"));
+
   auto* ram_override = new QGroupBox(tr("Memory Override"));
   auto* ram_override_layout = new QVBoxLayout();
   ram_override->setLayout(ram_override_layout);
@@ -199,6 +233,18 @@ void AdvancedPane::ConnectLayout()
     Update();
   });
 
+  connect(m_vi_rate_override_slider, &QSlider::valueChanged, [this](int oc_factor) {
+    const float factor = m_vi_rate_override_slider->value() / 100.f;
+    Config::SetBaseOrCurrent(Config::MAIN_VI_OVERCLOCK, factor);
+    Update();
+  });
+
+  m_ram_override_checkbox->setChecked(Config::Get(Config::MAIN_RAM_OVERRIDE_ENABLE));
+  connect(m_ram_override_checkbox, &QCheckBox::toggled, [this](bool enable_ram_override) {
+    Config::SetBaseOrCurrent(Config::MAIN_RAM_OVERRIDE_ENABLE, enable_ram_override);
+    Update();
+  });
+
   connect(m_mem1_override_slider, &QSlider::valueChanged, [this](int slider_value) {
     const u32 mem1_size = m_mem1_override_slider->value() * 0x100000;
     Config::SetBaseOrCurrent(Config::MAIN_MEM1_SIZE, mem1_size);
@@ -222,6 +268,7 @@ void AdvancedPane::Update()
 {
   const bool is_uninitialized = Core::IsUninitialized(Core::System::GetInstance());
   const bool enable_cpu_clock_override_widgets = Config::Get(Config::MAIN_OVERCLOCK_ENABLE);
+  const bool enable_vi_rate_override_widgets = Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE);
   const bool enable_ram_override_widgets = Config::Get(Config::MAIN_RAM_OVERRIDE_ENABLE);
   const bool enable_custom_rtc_widgets =
       Config::Get(Config::MAIN_CUSTOM_RTC_ENABLE) && is_uninitialized;
@@ -264,6 +311,30 @@ void AdvancedPane::Update()
     return tr("%1% (%2 MHz)").arg(QString::number(percent), QString::number(clock));
   }());
 
+  QFont vi_bf = font();
+  vi_bf.setBold(Config::GetActiveLayerForConfig(Config::MAIN_VI_OVERCLOCK_ENABLE) !=
+                Config::LayerType::Base);
+  m_vi_rate_override_checkbox->setFont(vi_bf);
+  m_vi_rate_override_checkbox->setChecked(enable_vi_rate_override_widgets);
+
+  m_vi_rate_override_slider->setEnabled(enable_vi_rate_override_widgets);
+  m_vi_rate_override_slider_label->setEnabled(enable_vi_rate_override_widgets);
+
+  {
+    const QSignalBlocker blocker(m_vi_rate_override_slider);
+    m_vi_rate_override_slider->setValue(
+        static_cast<int>(std::round(Config::Get(Config::MAIN_VI_OVERCLOCK) * 100.f)));
+  }
+
+  m_vi_rate_override_slider_label->setText([] {
+    int percent = static_cast<int>(std::round(Config::Get(Config::MAIN_VI_OVERCLOCK) * 100.f));
+    float vps =
+        static_cast<float>(Core::System::GetInstance().GetVideoInterface().GetTargetRefreshRate());
+    if (vps == 0.0f || !Config::Get(Config::MAIN_VI_OVERCLOCK_ENABLE))
+      vps = 59.94f * Config::Get(Config::MAIN_VI_OVERCLOCK);
+    return tr("%1% (%2 VPS)").arg(QString::number(percent), QString::number(vps, 'f', 2));
+  }());
+
   m_ram_override_checkbox->setEnabled(is_uninitialized);
   SignalBlocking(m_ram_override_checkbox)->setChecked(enable_ram_override_widgets);
 
diff --git a/Source/Core/DolphinQt/Settings/AdvancedPane.h b/Source/Core/DolphinQt/Settings/AdvancedPane.h
index ff449aca65..6493e71a73 100644
--- a/Source/Core/DolphinQt/Settings/AdvancedPane.h
+++ b/Source/Core/DolphinQt/Settings/AdvancedPane.h
@@ -39,6 +39,10 @@ private:
   QSlider* m_cpu_clock_override_slider;
   QLabel* m_cpu_clock_override_slider_label;
 
+  ConfigBool* m_vi_rate_override_checkbox;
+  QSlider* m_vi_rate_override_slider;
+  QLabel* m_vi_rate_override_slider_label;
+
   ConfigBool* m_custom_rtc_checkbox;
   QDateTimeEdit* m_custom_rtc_datetime;
 
diff --git a/Source/Core/VideoCommon/FrameDumpFFMpeg.cpp b/Source/Core/VideoCommon/FrameDumpFFMpeg.cpp
index ea8bda7893..44ec0a6a27 100644
--- a/Source/Core/VideoCommon/FrameDumpFFMpeg.cpp
+++ b/Source/Core/VideoCommon/FrameDumpFFMpeg.cpp
@@ -62,13 +62,13 @@ struct FrameDumpContext
 
 namespace
 {
-AVRational GetTimeBaseForCurrentRefreshRate()
+AVRational GetTimeBaseForCurrentRefreshRate(s64 max_denominator)
 {
   auto& vi = Core::System::GetInstance().GetVideoInterface();
   int num;
   int den;
   av_reduce(&num, &den, int(vi.GetTargetRefreshRateDenominator()),
-            int(vi.GetTargetRefreshRateNumerator()), std::numeric_limits<int>::max());
+            int(vi.GetTargetRefreshRateNumerator()), max_denominator);
   return AVRational{num, den};
 }
 
@@ -248,11 +248,16 @@ bool FFMpegFrameDump::CreateVideoFile()
     return false;
   }
 
+  m_max_denominator = std::numeric_limits<s64>::max();
+
   // Force XVID FourCC for better compatibility when using H.263
   if (codec->id == AV_CODEC_ID_MPEG4)
+  {
     m_context->codec->codec_tag = MKTAG('X', 'V', 'I', 'D');
+    m_max_denominator = std::numeric_limits<unsigned short>::max();
+  }
 
-  const auto time_base = GetTimeBaseForCurrentRefreshRate();
+  const auto time_base = GetTimeBaseForCurrentRefreshRate(m_max_denominator);
 
   INFO_LOG_FMT(FRAMEDUMP, "Creating video file: {} x {} @ {}/{} fps", m_context->width,
                m_context->height, time_base.den, time_base.num);
@@ -535,7 +540,7 @@ FrameState FFMpegFrameDump::FetchState(u64 ticks, int frame_number) const
   state.frame_number = frame_number;
   state.savestate_index = m_savestate_index;
 
-  const auto time_base = GetTimeBaseForCurrentRefreshRate();
+  const auto time_base = GetTimeBaseForCurrentRefreshRate(m_max_denominator);
   state.refresh_rate_num = time_base.den;
   state.refresh_rate_den = time_base.num;
   return state;
diff --git a/Source/Core/VideoCommon/FrameDumpFFMpeg.h b/Source/Core/VideoCommon/FrameDumpFFMpeg.h
index 8431e24274..87387b3e41 100644
--- a/Source/Core/VideoCommon/FrameDumpFFMpeg.h
+++ b/Source/Core/VideoCommon/FrameDumpFFMpeg.h
@@ -4,6 +4,7 @@
 #pragma once
 
 #include <ctime>
+#include <limits>
 #include <memory>
 
 #include "Common/CommonTypes.h"
@@ -62,6 +63,9 @@ private:
   // Used for filename generation.
   std::time_t m_start_time = {};
   u32 m_file_index = 0;
+
+  // Some codecs (like MPEG4) have a limit to this
+  int64_t m_max_denominator = std::numeric_limits<s64>::max();
 };
 
 #if !defined(HAVE_FFMPEG)