The Script code is:
--[[
obs-hotkey-window-capture v0.1
Allows using a hotkey to change capture window for Window Capture
sources.
Partly derived from
https://obsproject.com/forum/resources/bounce.947/
MIT Licensed
]]--
local obs = obslua
local bit = require('bit')
local ffi = require('ffi')
--- name of source to modify
local source_name = ''
--- scene item to be adjusted
local scene_item = nil
--- the hotkey assigned to window_capture_foreground in OBS's hotkey config
local hotkey_id = obs.OBS_INVALID_HOTKEY_ID
ffi.cdef[[
void* GetAncestor(void *hwnd, unsigned int flags);
void* GetForegroundWindow();
int GetWindowTextLengthA(void* hwnd);
int GetWindowTextA(void* hwnd, char* str, int count);
int GetClassNameA(void* hwnd, char* str, int count);
]]
local function get_active_window_title()
local hwnd = ffi.C.GetAncestor(ffi.C.GetForegroundWindow(), 3)
local sz = ffi.C.GetWindowTextLengthA(hwnd)
local ws = ffi.new('char[?]', sz)
ffi.C.GetWindowTextA(hwnd, ws, sz+1)
return ffi.string(ws)
end
local function get_active_window_class()
local hwnd = ffi.C.GetAncestor(ffi.C.GetForegroundWindow(), 3)
local ws = ffi.new('char[?]', 64)
ffi.C.GetClassNameA(hwnd, ws, 64)
return ffi.string(ws)
end
--- get a list of source names, sorted alphabetically
local function get_source_names()
local sources = obs.obs_enum_sources()
local source_names = {}
if sources then
for _, source in ipairs(sources) do
-- exclude Desktop Audio and Mic/Aux by their capabilities
local capability_flags = obs.obs_source_get_output_flags(source)
if bit.band(capability_flags, obs.OBS_SOURCE_DO_NOT_SELF_MONITOR) == 0 and
capability_flags ~= bit.bor(obs.OBS_SOURCE_AUDIO, obs.OBS_SOURCE_DO_NOT_DUPLICATE) then
table.insert(source_names, obs.obs_source_get_name(source))
end
end
end
obs.source_list_release(sources)
table.sort(source_names, function(a, b)
return string.lower(a) < string.lower(b)
end)
return source_names
end
function find_scene_item()
if not source_name or source_name == '' then
obs.script_log(obs.LOG_INFO, 'no source name')
return false
end
local source = obs.obs_frontend_get_current_scene()
if not source then
obs.script_log(obs.LOG_INFO, 'no current scene')
return false
end
local scene = obs.obs_scene_from_source(source)
obs.obs_source_release(source)
scene_item = obs.obs_scene_find_source(scene, source_name)
scene_item = obs.obs_sceneitem_get_source(scene_item)
if scene_item then
return true
end
obs.script_log(obs.LOG_INFO, source_name .. ' not found')
return false
end
function script_description()
return 'Allows using a hotkey to change capture window for Window Capture sources.'
end
function script_properties()
local props = obs.obs_properties_create()
local source = obs.obs_properties_add_list(
props,
'source',
'Source:',
obs.OBS_COMBO_TYPE_EDITABLE,
obs.OBS_COMBO_FORMAT_STRING)
for _, name in ipairs(get_source_names()) do
obs.obs_property_list_add_string(source, name, name)
end
return props
end
function script_update(settings)
source_name = obs.obs_data_get_string(settings, 'source')
find_scene_item()
end
function script_load(settings)
hotkey_id = obs.obs_hotkey_register_frontend('window_capture_foreground', 'Set Window Capture to foreground', window_capture_foreground)
local hotkey_save_array = obs.obs_data_get_array(settings, 'window_capture_foreground')
obs.obs_hotkey_load(hotkey_id, hotkey_save_array)
obs.obs_data_array_release(hotkey_save_array)
obs.obs_frontend_add_event_callback(on_event)
end
function on_event(event)
if event == obs.OBS_FRONTEND_EVENT_SCENE_CHANGED then
find_scene_item()
end
end
function script_save(settings)
local hotkey_save_array = obs.obs_hotkey_save(hotkey_id)
obs.obs_data_set_array(settings, 'window_capture_foreground', hotkey_save_array)
obs.obs_data_array_release(hotkey_save_array)
end
function window_capture_foreground(pressed)
if not pressed then
return
end
if not scene_item then
obs.script_log(obs.LOG_INFO, 'no window capture source')
return
end
local window_title = get_active_window_title()
local window_class = get_active_window_class()
local data = obs.obs_source_get_settings(scene_item)
obs.obs_data_set_string(data, 'window', window_title .. ':' .. window_class .. ': ')
obs.obs_source_update(scene_item, data)
obs.obs_data_release(data)
end
