OBS Hue Shift over Time

hue_shift.py

# How to use this script in OBS:
# You need Python 3.6 installed
# 1. Open OBS > Tools > Scripts
# 2. Copypaste the Python 3.6 install directory into Python Settings tab.
# 3. Download this file onto your computer and put it somewhere safe
# 4. Add the script to the list of Loaded Scripts by clicking the + at the bottom left
# 5. Select the script from the list and select the correct output source you want to apply the effect to.
#       If you can't find the correct source, scroll to the bottom of the file to see if your source is filtered out
#       The source you selected must have a Color Correction filter, that has been renamed to "Hue Shift".
#           The script won't work otherwise. I couldn't figure out how to list all the filters in a dropdown because 
#           OBS' documentation on C types in Python are poor.
# 6. Set your desired effect velocity (360 = 1 rainbow per second)
# 7. Click Start / Stop
# The script comes as-is and hasn't been tested for long periods of time for memory leaks etc
#
# The code is released under the MIT license.

import obspython as obs

active = False

hue_velocity = 0.0  # Degrees per second

# Angle of the hue shift (-180 to 180, but OBS seems to handle values outside of this range properly)
hue_shift_value = 0.0

source_name = ""
update_interval = 30  # Milliseconds


def update_hue(reset=False):
    global source_name
    global hue_shift_value

    # If the update is called with reset intention, set the hue to normal (0)
    if reset:
        hue_shift_value = 0

    source = obs.obs_get_source_by_name(source_name)
    if source is not None:
        hue_filter = obs.obs_source_get_filter_by_name(source, "Hue Shift")
        if hue_filter is not None:
            # Get the settings data object for the filter
            filter_settings = obs.obs_source_get_settings(hue_filter)

            # Update the hue_shift property and update the filter with the new settings
            obs.obs_data_set_double(
                filter_settings,
                "hue_shift",
                hue_shift_value
            )
            obs.obs_source_update(hue_filter, filter_settings)

            # Release the resources
            obs.obs_data_release(filter_settings)
            obs.obs_source_release(hue_filter)

        obs.obs_source_release(source)


def timer_callback():
    global hue_shift_value
    global hue_velocity
    global update_interval

    # Update the hue_shift value. Velocity is degrees / second, update_interval is in milliseconds
    hue_shift_value += hue_velocity * update_interval / 1000
    hue_shift_value = hue_shift_value % 360
    update_hue()


def activate():
    global active
    global update_interval

    if active:
        obs.timer_add(timer_callback, update_interval)
    else:
        obs.timer_remove(timer_callback)


def start_button_clicked(props, p):
    global active

    active = not active
    if not active:
        update_hue(True)

    activate()


def activate_signal(cd):
    global source_name

    source = obs.calldata_source(cd, "source")
    if source is not None:
        name = obs.obs_source_get_name(source)
        if name == source_name:
            activate()


def source_activated(cd):
    activate_signal(cd)


def source_deactivated(cd):
    activate_signal(cd)


def script_load(settings):
    sh = obs.obs_get_signal_handler()
    obs.signal_handler_connect(sh, "source_activate", source_activated)
    obs.signal_handler_connect(sh, "source_deactivate", source_deactivated)


def script_description():
    return '''Changes the Hue Shift property of a color correction filter over time
    
The selected source must have a Color Correction filter renamed as "Hue Shift" for the effect to work.

Script with love by Hegemege'''


def script_update(settings):
    global hue_velocity
    global source_name
    global hue_shift_value

    hue_velocity = obs.obs_data_get_double(settings, "hue_shift_velocity")
    source_name = obs.obs_data_get_string(settings, "source")
    hue_shift_value = 0

    update_hue(True)


def script_defaults(settings):
    obs.obs_data_set_default_double(settings, "hue_shift_velocity", 360.0)


def script_properties():
    props = obs.obs_properties_create()
    obs.obs_properties_add_float(
        props, "hue_shift_velocity", "Hue Shift Velocity", -10000, 10000, 0.1)

    source_prop = obs.obs_properties_add_list(
        props,
        "source",
        "Source",
        obs.OBS_COMBO_TYPE_EDITABLE,
        obs.OBS_COMBO_FORMAT_STRING
    )
    sources = obs.obs_enum_sources()
    if sources is not None:
        for source in sources:
            source_id = obs.obs_source_get_id(source)
            
            # Only list sources with 'capture' in the name. 
            # To list all sources, remove the if and de-indent the two lines below it or replace the row with 'if True:' if you are not a rpogrammer)
            if 'capture' in source_id:
                name = obs.obs_source_get_name(source)
                obs.obs_property_list_add_string(source_prop, name, name)
    obs.source_list_release(sources)

    obs.obs_properties_add_button(
        props, "reset_button", "Start / Stop", start_button_clicked)

    return props

im getting an issue where the hue shift gradually speeds up over time? i assume this isn't intended, is there any way to fix this? i dont know any coding so the answer could be staring me right in the face but im just not sure.

im getting an issue where the hue shift gradually speeds up over time? i assume this isn't intended, is there any way to fix this? i dont know any coding so the answer could be staring me right in the face but im just not sure.

I'm not using the script at the moment, so I can't confirm the problem you're suggesting. That said, I just skimmed the code and I didn't see anything in the hue shifting math that would suggest an increase in hue_velocity or update_interval, which is where I would expect to see a math issue.

Have you tried running it with the default values?

@Hegemege this can be fixed by making the hue shift over time.