Override config for setting CRT resolutions per-core or per-game in RetroArch

CRT resolution override.cfg

## Override config for setting CRT resolutions per core or per game.
## Place this in $rgui_config_directory/[Core Name]/[Core Name].cfg or $rgui_config_directory/[Core Name]/[Content Filename].cfg to have it loaded automatically when override loading is enabled
## e.g $rgui_config_directory/MAME/mslug.cfg or $rgui_config_directory/Mednafen PSX/Mednafen PSX.cfg

# Fullscreen resolution. Resolution of 0 uses the resolution of the desktop.
# Note, you must create the modeline in your OS video driver settings for this to work.
video_fullscreen_x = 3840
video_fullscreen_y = 480

# Refresh rate of the resolution mode.
# As of 1.3.0, this is used to set the video mode refresh rate on Windows.
# If using black frame insertion, set this to 1/2 of the actual display refresh rate.
video_refresh_rate = 60.0

# A floating point value for video aspect ratio (width / height) used when aspect_ratio_index is 19 (Config)
# If this is not set, aspect ratio is assumed to be automatic.
# If using a superwide CRT resolution, set this to (video_fullscreen_x / video_fullscreen_y)
# Note: If you want to force a specific pixel aspect ratio on a superwide resolution, set video_aspect_ratio = ((video_fullscreen_x / video_fullscreen_y) * (((base_width * (pixel_aspect_ratio)) / base_height) / (display_aspect_ratio)))
video_aspect_ratio = 8.0

# Index of the aspect ratio selection in the menu.
# 19 = Config, 20 = 1:1 PAR, 21 = Core Provided, 22 = Custom Viewport
aspect_ratio_index = 19

# Custom viewport dimensions that are used if aspect_ratio_index is 22 (Custom Viewport)
custom_viewport_width = 3840
custom_viewport_height = 448

# Which monitor to prefer. 0 (default) means no particular monitor is preferred, 1 and up (1 being first monitor),
# suggests RetroArch to use that particular monitor.
video_monitor_index = 0

# Start in fullscreen. Can be changed at runtime.
video_fullscreen = true

# If fullscreen, prefer using a windowed fullscreen mode.
# Must be set to false for video_fullscreen_x and video_fullscreen_y to be used.
video_windowed_fullscreen = false

# Inserts a black frame in between frames.
# Useful for 120 Hz monitors who want to play 60 Hz material with eliminated ghosting.
# video_refresh_rate should still be configured as if it is a 60 Hz monitor (divide refresh rate by 2).
# The video mode selected will have a refresh rate of twice the value of video_refresh_rate when this is set to true.
video_black_frame_insertion = false

# Interval at which a Vsync swap is performed.
# 1 is normal, 2 is doubled frames, 3 is tripled frames, etc.
video_swap_interval = 1

# Only scales video in integer steps.
# The base size depends on system-reported geometry and aspect ratio.
# Automatically centers custom viewports as well
video_scale_integer = true

# Path to shader. Shader can be either Cg, CGP (Cg preset) or GLSL, GLSLP (GLSL preset)
video_shader = :\shaders\cgp\tvout+interlacing\tvout+interlacing.cgp

# Forces cropping of overscanned frames.
# Exact behavior of this option is implementation specific.
# Set this to false when using a CRT, since it is technically more accurate to draw the complete image and use the CRT geometry controls to physically crop those areas. 
# However set to true for Mednafen cores because they have extra padding when this settings is false.
video_crop_overscan = false

# Forces a certain rotation of the screen.
# The rotation is added to rotations which the libretro core sets (see video_allow_rotate).
# The angle is <value> * 90 degrees counter-clockwise.
video_rotation = 0

# Menu driver to use. rgui, glui, xmb etc. 
# Use rgui if you are using superwide resolutions on CRT. The other menu drivers don't display correctly due to using rendered truetype fonts instead of scaled bitmap fonts.
# Note: hot swapping configs in the menu that use different menu drivers can cause a crash currently.
menu_driver = rgui