Some tweaks for Futatabi.

[ultimatescore] / nageru / ultimate.lua

-- Nageru theme for TFK mini-tournament 2017, based on the default theme.

local futatabi_server = "http://gruessi.trd.sesse.net:9096"

local state = {
        transition_start = -2.0,
        transition_end = -1.0,
        transition_type = 0,
        transition_src_signal = 0,
        transition_dst_signal = 0,

        neutral_colors = {
                {0.5, 0.5, 0.5},  -- Input 0.
                {0.5, 0.5, 0.5},  -- Input 1.
                {0.5, 0.5, 0.5},  -- Input 2.
                {0.5, 0.5, 0.5},  -- Input 3.
                {0.5, 0.5, 0.5},  -- Input 4.
                {0.5, 0.5, 0.5}   -- Input 5.
                -- Will also be filled with VIDEO_SIGNAL_NUM below.
        },

        overlay_transition_start = -2.0,
        overlay_transition_end = -1.0,
        overlay_alpha_src = 0.0,
        overlay_alpha_dst = 1.0,
        overlay_enabled = false,

        stinger_in_progress = false,
        stinger_frame = 0,
        stinger_src_signal = 0,
        stinger_dst_signal = 0,
        stinger_save_overlay = false,

        live_signal_num = 0,
        preview_signal_num = 1
}
local NUM_CAMERAS = 6  -- Remember to update neutral_colors, too.

-- Valid values for live_signal_num and preview_signal_num.
local INPUT0_SIGNAL_NUM = 0
local INPUT1_SIGNAL_NUM = 1
local INPUT2_SIGNAL_NUM = 2
local INPUT3_SIGNAL_NUM = 3
local INPUT4_SIGNAL_NUM = 4
local INPUT5_SIGNAL_NUM = 5
local SBS_SIGNAL_NUM = NUM_CAMERAS
local STATIC_SIGNAL_NUM = NUM_CAMERAS + 1
local VIDEO_SIGNAL_NUM = NUM_CAMERAS + 2

state.neutral_colors[VIDEO_SIGNAL_NUM - INPUT0_SIGNAL_NUM + 1] = {0.5, 0.5, 0.5}

-- Preview-only signal showing the current signal with the overlay.
-- Not valid for live_signal_num!
local OVERLAY_SIGNAL_NUM = NUM_CAMERAS + 3

-- Valid values for transition_type. (Cuts are done directly, so they need no entry.)
local NO_TRANSITION = 0
local ZOOM_TRANSITION = 1
local FADE_TRANSITION = 2

-- Last width/height/frame rate for each channel, if we have it.
-- Note that unlike the values we get from Nageru, the resolution is per
-- frame and not per field, since we deinterlace.
local last_resolution = {}

local cef_path = Nageru.THEME_PATH:match("(.*)/nageru/")
local cef_input = HTMLInput.new("file://" .. cef_path .. "/score.html")
cef_input:execute_javascript_async("play()")

local bg_video = VideoInput.new(cef_path .. "/flow-720.mp4", Nageru.VIDEO_FORMAT_YCBCR)
-- local iptv_video = VideoInput.new("http://10.34.129.69:9060/1/v.flv", Nageru.VIDEO_FORMAT_YCBCR)
local iptv_video = VideoInput.new(futatabi_server, Nageru.VIDEO_FORMAT_YCBCR)
iptv_video:change_rate(10.0)

local static_image = ImageInput.new(cef_path .. "/nageru/dsn-bg.png")

function reload_cef()
        cef_input:reload()
        cef_input:execute_javascript_async("play()")
end

function disconnect_iptv()
        iptv_video:disconnect()
end

-- An overlay with variable alpha.
function make_overlay(scene, base)
        local image = scene:add_input(cef_input)
        local multiply_effect = scene:add_effect(MultiplyEffect.new())
        local overlay_effect = scene:add_optional_effect(OverlayEffect.new(), base, multiply_effect)
        return {
                image = image,
                multiply_effect = multiply_effect,
                overlay_effect = overlay_effect
        }
end

function make_fade_input(scene)
        local ret = {
                input = scene:add_input(),
                resample_effect = scene:add_optional_effect(ResampleEffect.new()),  -- Activated if scaling.
                wb_effect = scene:add_optional_effect(WhiteBalanceEffect.new())  -- Activated for video inputs.
        }
        ret.overlay = make_overlay(scene, ret.wb_effect)
        return ret
end

-- A scene to fade between two inputs, of which either can be a picture
-- or a live input.
function make_fade_scene()
        local scene = Scene.new(16, 9)

        -- If fading between two live inputs, the overlay is put on top.
        -- If fading between the static picture and a live input,
        -- the overlay is put on the live input.
        local input0 = make_fade_input(scene)
        local input1 = make_fade_input(scene)
        local mix_effect = scene:add_effect(MixEffect.new(), input0.overlay.overlay_effect, input1.overlay.overlay_effect)
        local overlay = make_overlay(scene, mix_effect)

        -- At most one overlay can be active at any given time.
        input0.overlay.overlay_effect:promise_to_disable_if_enabled(input1.overlay.overlay_effect)
        input0.overlay.overlay_effect:promise_to_disable_if_enabled(overlay.overlay_effect)
        input1.overlay.overlay_effect:promise_to_disable_if_enabled(input0.overlay.overlay_effect)
        input1.overlay.overlay_effect:promise_to_disable_if_enabled(overlay.overlay_effect)
        overlay.overlay_effect:promise_to_disable_if_enabled(input0.overlay.overlay_effect)
        overlay.overlay_effect:promise_to_disable_if_enabled(input1.overlay.overlay_effect)

        scene:finalize(true)  -- Only used live, don't bother creating LQ versions.

        return {
                scene = scene,
                input0 = input0,
                input1 = input1,
                mix_effect = mix_effect,
                overlay = overlay
        }
end
fade_scene = make_fade_scene()

function make_sbs_input(scene, has_overlay)
        local input = scene:add_input()
        return {
                input = input,
                overlay = has_overlay and make_overlay(scene, input) or nil,
                resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new()}),
                wb_effect = scene:add_effect(WhiteBalanceEffect.new()),
                padding_effect = scene:add_effect(IntegralPaddingEffect.new())
        }
end

-- Side-by-side scene.
function make_sbs_scene()
        local scene = Scene.new(16, 9)

        local bg = scene:add_input(bg_video)
        local input0 = make_sbs_input(scene, true)
        local input1 = make_sbs_input(scene, false)

        input0.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 0.0)
        input1.padding_effect:set_vec4("border_color", 0.0, 0.0, 0.0, 0.0)

        input0.input:display(0)
        input1.input:display(1)

        local i0 = scene:add_effect(OverlayEffect.new(), bg, input0.padding_effect)
        scene:add_effect(OverlayEffect.new(), i0, input1.padding_effect)
        scene:finalize()

        return {
                scene = scene,
                input0 = input0,
                input1 = input1,
                overlay = input0.overlay  -- May be nil.
        }
end
local sbs_scene = make_sbs_scene()

function make_simple_scene_no_finalize()
        local scene = Scene.new(16, 9)

        local input = scene:add_input()
        local resample_effect = scene:add_effect({ResampleEffect.new(), ResizeEffect.new(), IdentityEffect.new()})
        local wb_effect = scene:add_effect(WhiteBalanceEffect.new())
        local overlay = make_overlay(scene, wb_effect)

        return {
                scene = scene,
                input = input,
                wb_effect = wb_effect,
                resample_effect = resample_effect,
                overlay = overlay
        }
end

-- A scene to show a single input on screen.
function make_simple_scene()
        local scene = make_simple_scene_no_finalize()
        scene.scene:finalize()
        return scene
end

local simple_scene = make_simple_scene()

-- Load all the stinger frames.
local stinger_images = {}
for idx=0,24 do
        local filename = cef_path .. "/stinger/blur" .. string.rep("0", 3 - string.len(tostring(idx))) .. idx .. ".png"
        stinger_images[idx] = ImageInput.new(filename)
end

-- A scene to show a single input on screen, with a stinger on top.
function make_stinger_scene()
        local scene = make_simple_scene_no_finalize()
        scene.stinger_input = scene.scene:add_input()
        scene.scene:add_effect(OverlayEffect.new(), scene.overlay.overlay_effect, scene.stinger_input)
        scene.scene:finalize()
        return scene
end
local stinger_scene = make_stinger_scene()

-- A scene to show a single static picture on screen. Never with HTML overlay.
local static_scene = Scene.new(16, 9)
static_scene:add_input(static_image)
static_scene:finalize()

-- A scene to show the overlay and nothing more. LQ only,
-- since it is not a valid live signal.
local overlay_scene_lq = Scene.new(16, 9)
local overlay_scene_lq_input = overlay_scene_lq:add_input(cef_input)
overlay_scene_lq:finalize(false)

function needs_scale(signals, signal_num, width, height)
        if signal_num == STATIC_SIGNAL_NUM then
                -- We assume this is already correctly scaled at load time.
                return false
        end
        assert(is_plain_signal(signal_num))
        return (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height)
end

function set_scale_parameters_if_needed(scene, signals, signal_num, width, height, hq)
        -- Futatabi rescaling will be linear, but original frames come back unscaled;
        -- make them linear, too, so that we don't get more sharpness on every other
        -- frame. This won't be right for fading, but it's probably hard to notice.
        if signal_num == VIDEO_SIGNAL_NUM then
                hq = false
        end

        if needs_scale(signals, signal_num, width, height) then
                if hq then
                        scene.resample_effect:choose(ResampleEffect)  -- High-quality resampling.
                else
                        scene.resample_effect:choose(ResizeEffect)  -- Low-quality resampling.
                end
                scene.resample_effect:set_int("width", width)
                scene.resample_effect:set_int("height", height)
        else
                scene.resample_effect:disable()
        end

end

-- API ENTRY POINT
-- Returns the number of outputs in addition to the live (0) and preview (1).
-- Called only once, at the start of the program.
function num_channels()
        return NUM_CAMERAS + 4  -- sbs, static picture, video and overlay
end

function is_plain_signal(num)
        return (num >= INPUT0_SIGNAL_NUM and num <= INPUT5_SIGNAL_NUM) or (num == VIDEO_SIGNAL_NUM)
end

-- Helper function to write e.g. “720p60”. The difference between this
-- and get_channel_resolution_raw() is that this one also can say that
-- there's no signal.
function get_channel_resolution(signal_num)
        local res = last_resolution[signal_num]
        if (not res) or not res.is_connected then
                return "disconnected"
        end
        if res.height <= 0 then
                return "no signal"
        end
        if not res.has_signal then
                if res.height == 525 then
                        -- Special mode for the USB3 cards.
                        return "no signal"
                end
                return get_channel_resolution_raw(res) .. ", no signal"
        else
                return get_channel_resolution_raw(res)
        end
end

-- Helper function to write e.g. “60” or “59.94”.
function get_frame_rate(res)
        local nom = res.frame_rate_nom
        local den = res.frame_rate_den
        if nom % den == 0 then
                return nom / den
        else
                return string.format("%.2f", nom / den)
        end
end

-- Helper function to write e.g. “720p60”.
function get_channel_resolution_raw(res)
        if res.interlaced then
                return res.height .. "i" .. get_frame_rate(res)
        else
                return res.height .. "p" .. get_frame_rate(res)
        end
end

function get_futatabi_status(str)
        local num_fields = 0
        local fields = {}
        for word in string.gmatch(str, '([^;]+)') do
                table.insert(fields, word)
                num_fields = num_fields + 1
        end
        if num_fields >= 4 then
                return fields[4]
        else
                return "???"
        end
end

-- API ENTRY POINT
-- Returns the name for each additional channel (starting from 2).
-- Called at the start of the program, and then each frame for live
-- channels in case they change resolution.
function channel_name(channel)
        local signal_num = channel - 2
        if signal_num == INPUT0_SIGNAL_NUM then
                return "Main (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == INPUT1_SIGNAL_NUM then
                return "Secondary (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == INPUT2_SIGNAL_NUM then
                return "Goal L (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == INPUT3_SIGNAL_NUM then
                return "Goal R (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == INPUT4_SIGNAL_NUM then
                return "Commentators (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == INPUT5_SIGNAL_NUM then
                return "Laptop (" .. get_channel_resolution(signal_num) .. ")"
        elseif signal_num == SBS_SIGNAL_NUM then
                return "Side-by-side"
        elseif signal_num == STATIC_SIGNAL_NUM then
                return "Static picture"
        elseif signal_num == VIDEO_SIGNAL_NUM then
                local res = last_resolution[iptv_video:get_signal_num()]
                if (not res) or res.last_subtitle == nil then
                        return "Futatabi"
                else
                        return "Futatabi (" .. get_futatabi_status(res.last_subtitle) .. ")"
                end
        elseif signal_num == OVERLAY_SIGNAL_NUM then
                return "Overlay"
        end
end

-- API ENTRY POINT
-- Returns, given a channel number, which signal it corresponds to (starting from 0).
-- Should return -1 if the channel does not correspond to a simple signal.
-- (The information is used for whether right-click on the channel should bring up
-- an input selector or not.)
-- Called once for each channel, at the start of the program.
-- Will never be called for live (0) or preview (1).
function channel_signal(channel)
        if channel - 2 == VIDEO_SIGNAL_NUM then
                return iptv_video:get_signal_num()
        elseif is_plain_signal(channel - 2) then
                return channel - 2
        else
                return -1
        end
end

-- API ENTRY POINT
-- Called every frame. Returns the color (if any) to paint around the given
-- channel. Returns a CSS color (typically to mark live and preview signals);
-- "transparent" is allowed.
-- Will never be called for live (0) or preview (1).
function channel_color(channel)
        if state.transition_type ~= NO_TRANSITION then
                if channel_involved_in(channel, state.transition_src_signal) or
                   channel_involved_in(channel, state.transition_dst_signal) then
                        return "#f00"
                end
        else
                if channel_involved_in(channel, state.live_signal_num) then
                        return "#f00"
                end
        end
        if channel_involved_in(channel, state.preview_signal_num) then
                return "#0f0"
        end
        return "transparent"
end

function channel_involved_in(channel, signal_num)
        if is_plain_signal(signal_num) then
                return channel == (signal_num + 2)
        end
        if signal_num == SBS_SIGNAL_NUM then
                return is_sbs_participating_signal(channel - 2)
        end
        if signal_num == STATIC_SIGNAL_NUM then
                return (channel == NUM_CAMERAS)
        end
        if signal_num == VIDEO_SIGNAL_NUM then
                return (channel == NUM_CAMERAS + 1)
        end
        return false
end

-- API ENTRY POINT
-- Returns if a given channel supports setting white balance (starting from 2).
-- Called only once for each channel, at the start of the program.
function supports_set_wb(channel)
        return is_plain_signal(channel - 2)
end

-- API ENTRY POINT
-- Gets called with a new gray point when the white balance is changing.
-- The color is in linear light (not sRGB gamma).
function set_wb(channel, red, green, blue)
        if is_plain_signal(channel - 2) then
                state.neutral_colors[channel - 2 + 1] = { red, green, blue }
        end
end

function finish_transitions(t)
        if state.transition_type ~= NO_TRANSITION and t >= state.transition_end then
                state.live_signal_num = state.transition_dst_signal
                state.transition_type = NO_TRANSITION
        end

        -- Disable the overlay if it is no longer visible.
        if state.overlay_enabled and t > state.overlay_transition_end and state.overlay_alpha_dst == 0.0 then
                state.overlay_enabled = false
                print("Turning off overlay")
        end
end

function in_transition(t)
        return t >= state.transition_start and t <= state.transition_end
end

function is_sbs_participating_signal(signal_num)
        return signal_num == INPUT0_SIGNAL_NUM or signal_num == INPUT4_SIGNAL_NUM
end

function simple_signal_has_overlay(signal_num)
        -- The commentator output has no overlay on it.
        return signal_num ~= INPUT4_SIGNAL_NUM
end

-- API ENTRY POINT
-- Called every frame.
function get_transitions(t)
        if state.preview_signal_num == OVERLAY_SIGNAL_NUM then
                if t < state.overlay_transition_end then
                        -- Fade in progress.
                        return {}
                end
                if state.overlay_enabled then
                        return {"Overlay off", "", "Fade ovl out"}
                else
                        return {"Overlay on", "", "Fade ovl in"}
                end
        end

        if in_transition(t) then
                -- Transition already in progress, the only thing we can do is really
                -- cut to the preview. (TODO: Make an “abort” and/or “finish”, too?)
                return {"Cut"}
        end

        if state.live_signal_num == state.preview_signal_num then
                -- No transitions possible.
                return {}
        end

        if (is_plain_signal(state.live_signal_num) and state.preview_signal_num == VIDEO_SIGNAL_NUM) or
           (is_plain_signal(state.preview_signal_num) and state.live_signal_num == VIDEO_SIGNAL_NUM) then
                return {"Cut", "Sting", "Fade"}
        end

        if (is_plain_signal(state.live_signal_num) or state.live_signal_num == STATIC_SIGNAL_NUM) and
           (is_plain_signal(state.preview_signal_num) or state.preview_signal_num == STATIC_SIGNAL_NUM) then
                return {"Cut", "", "Fade"}
        end

        -- Various zooms.
        if state.live_signal_num == SBS_SIGNAL_NUM and is_sbs_participating_signal(state.preview_signal_num) then
                return {"Cut", "Zoom in"}
        elseif is_sbs_participating_signal(state.live_signal_num) and state.preview_signal_num == SBS_SIGNAL_NUM then
                return {"Cut", "Zoom out"}
        end

        return {"Cut"}
end

function swap_preview_live()
        local temp = state.live_signal_num
        state.live_signal_num = state.preview_signal_num
        state.preview_signal_num = temp
end

function start_transition(type_, t, duration)
        state.transition_start = t
        state.transition_end = t + duration
        state.transition_type = type_
        state.transition_src_signal = state.live_signal_num
        state.transition_dst_signal = state.preview_signal_num
        state.stinger_in_progress = false
        swap_preview_live()
end

-- API ENTRY POINT
-- Called when the user clicks a transition button.
function transition_clicked(num, t)
        if state.preview_signal_num == OVERLAY_SIGNAL_NUM then
                if num == 0 then
                        -- Cut.
                        state.overlay_transition_start = -2.0
                        state.overlay_transition_end = -1.0
                        if state.overlay_enabled then
                                state.overlay_enabled = false
                                state.overlay_alpha_src = 0.0
                                state.overlay_alpha_dst = 0.0
                        else
                                state.overlay_enabled = true
                                state.overlay_alpha_src = 1.0
                                state.overlay_alpha_dst = 1.0
                        end
                elseif num == 2 then
                        -- Fade.
                        state.overlay_transition_start = t
                        state.overlay_transition_end = t + 1.0
                        if state.overlay_enabled then
                                state.overlay_alpha_src = 1.0
                                state.overlay_alpha_dst = 0.0
                        else
                                state.overlay_alpha_src = 0.0
                                state.overlay_alpha_dst = 1.0
                        end
                        state.overlay_enabled = true
                end
                return
        end

        if num == 0 then
                -- Cut.
                if in_transition(t) then
                        -- Ongoing transition; finish it immediately before the cut.
                        finish_transitions(state.transition_end)
                end

                swap_preview_live()
                state.stinger_in_progress = false
        elseif num == 1 then
                -- Zoom or sting.
                finish_transitions(t)

                if state.live_signal_num == state.preview_signal_num then
                        -- Nothing to do.
                        return
                end

                if (is_plain_signal(state.live_signal_num) and state.preview_signal_num == VIDEO_SIGNAL_NUM) or
                   (is_plain_signal(state.preview_signal_num) and state.live_signal_num == VIDEO_SIGNAL_NUM) then
                        -- Sting.
                        if stinger_in_progress then
                                return
                        end

                        state.stinger_in_progress = true
                        state.stinger_frame = 0
                        state.stinger_src_signal = state.live_signal_num
                        state.stinger_dst_signal = state.preview_signal_num
                        return
                end

                if is_plain_signal(state.live_signal_num) and is_plain_signal(state.preview_signal_num) then
                        -- We can't zoom between these. Just make a cut.
                        io.write("Cutting from " .. state.live_signal_num .. " to " .. state.live_signal_num .. "\n")
                        swap_preview_live()
                        state.stinger_in_progress = false
                        return
                end

                if (state.live_signal_num == SBS_SIGNAL_NUM and is_sbs_participating_signal(state.preview_signal_num)) or
                   (state.preview_signal_num == SBS_SIGNAL_NUM and is_sbs_participating_signal(state.live_signal_num)) then
                        start_transition(ZOOM_TRANSITION, t, 1.0)
                end
        elseif num == 2 then
                finish_transitions(t)

                -- Fade.
                if (state.live_signal_num ~= state.preview_signal_num) and
                   (is_plain_signal(state.live_signal_num) or
                    state.live_signal_num == STATIC_SIGNAL_NUM) and
                   (is_plain_signal(state.preview_signal_num) or
                    state.preview_signal_num == STATIC_SIGNAL_NUM) then
                        start_transition(FADE_TRANSITION, t, 1.0)
                else
                        -- Fades involving SBS are ignored (we have no scene for it).
                end
        end
end

-- API ENTRY POINT
function channel_clicked(num)
        state.preview_signal_num = num
end

function setup_fade_input(state, input, signals, signal_num, width, height)
        if signal_num == STATIC_SIGNAL_NUM then
                input.input:display(static_image)
                input.wb_effect:disable()

                -- We assume this is already correctly scaled at load time.
                input.resample_effect:disable()
        else
                input.input:display(signal_num)
                input.wb_effect:enable()
                set_neutral_color(input.wb_effect, state.neutral_colors[signal_num - INPUT0_SIGNAL_NUM + 1])

                if (signals:get_width(signal_num) ~= width or signals:get_height(signal_num) ~= height) then
                        input.resample_effect:enable()
                        input.resample_effect:set_int("width", width)
                        input.resample_effect:set_int("height", height)
                else
                        input.resample_effect:disable()
                end
        end
end

function get_fade_scene(state, signals, t, width, height, input_resolution)
        local scene = fade_scene
        setup_fade_input(state, scene.input0, signals, state.transition_src_signal, width, height)
        setup_fade_input(state, scene.input1, signals, state.transition_dst_signal, width, height)

        local tt = calc_fade_progress(t, state.transition_start, state.transition_end)
        scene.mix_effect:set_float("strength_first", 1.0 - tt)
        scene.mix_effect:set_float("strength_second", tt)

        -- The commentator output has no overlay on it.
        local extra_alpha_factor = 1.0
        if not simple_signal_has_overlay(state.transition_src_signal) and
           not simple_signal_has_overlay(state.transition_dst_signal) then
                extra_alpha_factor = 0.0
        elseif not simple_signal_has_overlay(state.transition_src_signal) then
                extra_alpha_factor = tt
        elseif not simple_signal_has_overlay(state.transition_dst_signal) then
                extra_alpha_factor = 1.0 - tt
        end

        -- If fading between two live inputs, the overlay is put on top.
        -- If fading between the static picture and a live input,
        -- the overlay is put on the live input.
        scene.input0.overlay.overlay_effect:disable()
        scene.input1.overlay.overlay_effect:disable()
        scene.overlay.overlay_effect:disable()
        if state.overlay_enabled then
                local input0_live = (state.transition_src_signal ~= STATIC_SIGNAL_NUM)
                local input1_live = (state.transition_dst_signal ~= STATIC_SIGNAL_NUM)
                if input0_live and not input1_live then
                        scene.input0.overlay.overlay_effect:enable()
                        prepare_overlay_live(state, scene.input0, t, extra_alpha_factor)
                elseif input1_live and not input0_live then
                        scene.input1.overlay.overlay_effect:enable()
                        prepare_overlay_live(state, scene.input1, t, extra_alpha_factor)
                else
                        scene.overlay.overlay_effect:enable()
                        prepare_overlay_live(state, scene, t, extra_alpha_factor)
                end
        end
        return scene.scene
end

function fetch_input_resolution(signals, signal_num)
        local res = {
                width = signals:get_width(signal_num),
                height = signals:get_height(signal_num),
                interlaced = signals:get_interlaced(signal_num),
                has_signal = signals:get_has_signal(signal_num),
                is_connected = signals:get_is_connected(signal_num),
                frame_rate_nom = signals:get_frame_rate_nom(signal_num),
                frame_rate_den = signals:get_frame_rate_den(signal_num),
                last_subtitle = signals:get_last_subtitle(signal_num)
        }

        if res.interlaced then
                -- Convert height from frame height to field height.
                -- (Needed for e.g. place_rectangle.)
                res.height = res.height * 2

                -- Show field rate instead of frame rate; really for cosmetics only
                -- (and actually contrary to EBU recommendations, although in line
                -- with typical user expectations).
                res.frame_rate_nom = res.frame_rate_nom * 2
        end
        return res
end

local last_rate = 0.0

-- API ENTRY POINT
-- Called every frame. Get the scene for displaying at input <num>,
-- where 0 is live, 1 is preview, 2 is the first channel to display
-- in the bottom bar, and so on up to num_channels()+1. t is the
-- current time in seconds. width and height are the dimensions of
-- the output, although you can ignore them if you don't need them
-- (they're useful if you want to e.g. know what to resample by).
--
-- <signals> is basically an exposed InputState, which you can use to
-- query for information about the signals at the point of the current
-- frame. In particular, you can call get_width() and get_height()
-- for any signal number, and use that to e.g. assist in scene selection.
--
-- You should return scene to use, after having set any parameters you
-- want to set (through set_int() etc.). The parameters will be snapshot
-- at return time and used during rendering.
function get_scene(num, t, width, height, signals)
        local input_resolution = {}
        for signal_num=0,(NUM_CAMERAS-1) do
                input_resolution[signal_num] = fetch_input_resolution(signals, signal_num)
        end
        input_resolution[iptv_video:get_signal_num()] = fetch_input_resolution(signals, iptv_video:get_signal_num())
        last_resolution = input_resolution

        -- Save some CPU time if we're not having SBS on live.
        local new_rate
        if state.live_signal_num == SBS_SIGNAL_NUM or
           state.preview_signal_num == SBS_SIGNAL_NUM or
           state.transition_type == ZOOM_TRANSITION then
                new_rate = 1.0
        else
                new_rate = 0.0001
        end
        if new_rate ~= last_rate then
                -- Avoid waking up the video thread (which may be sleeping) if the rate is the same.
                bg_video:change_rate(new_rate)
                last_rate = new_rate
        end

        if num == 0 then  -- Live.
                -- See if we're in a transition.
                finish_transitions(t)
                if state.transition_type == ZOOM_TRANSITION then
                        -- Transition in or out of SBS.
                        sbs_scene.input0.overlay.overlay_effect:enable_if(state.overlay_enabled)
                        prepare_sbs_scene(state, sbs_scene, calc_zoom_progress(t), state.transition_type, state.transition_src_signal, state.transition_dst_signal, width, height, input_resolution, true)
                        prepare_overlay_live(state, sbs_scene, t, 1.0)
                        return sbs_scene.scene
                elseif state.transition_type == NO_TRANSITION and state.live_signal_num == SBS_SIGNAL_NUM then
                        -- Static SBS view.
                        sbs_scene.input0.overlay.overlay_effect:enable_if(state.overlay_enabled)
                        prepare_sbs_scene(state, sbs_scene, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, true)
                        prepare_overlay_live(state, sbs_scene, t, 1.0)
                        return sbs_scene.scene
                elseif state.transition_type == FADE_TRANSITION then
                        return get_fade_scene(state, signals, t, width, height, input_resolution)
                elseif is_plain_signal(state.live_signal_num) then
                        local overlay_really_enabled = state.overlay_enabled and simple_signal_has_overlay(state.live_signal_num)
                        if state.stinger_in_progress then
                                stinger_scene.overlay.overlay_effect:enable_if(overlay_really_enabled)
                                stinger_scene.input:display(state.live_signal_num)
                                set_scale_parameters_if_needed(stinger_scene, signals, state.live_signal_num, width, height, true)
                                set_neutral_color_from_signal(state, stinger_scene.wb_effect, state.live_signal_num)

                                stinger_scene.stinger_input:display(stinger_images[state.stinger_frame])
                                state.stinger_frame = state.stinger_frame + 1
                                if state.stinger_frame >= 25 then
                                        state.stinger_in_progress = false
                                        state.preview_signal_num = state.stinger_src_signal
                                        state.live_signal_num = state.stinger_dst_signal

                                        if state.stinger_dst_signal == VIDEO_SIGNAL_NUM then
                                                -- Turn off the overlay when playing video.
                                                state.stinger_save_overlay = state.overlay_enabled
                                                state.overlay_enabled = false
                                        else
                                                -- Restore the state.
                                                state.overlay_enabled = state.stinger_save_overlay
                                        end
                                end

                                if overlay_really_enabled then
                                        prepare_overlay_live(state, stinger_scene, t, 1.0)
                                end
                                return stinger_scene.scene
                        else
                                simple_scene.overlay.overlay_effect:enable_if(overlay_really_enabled)
                                simple_scene.input:display(state.live_signal_num)
                                set_scale_parameters_if_needed(simple_scene, signals, state.live_signal_num, width, height, true)
                                set_neutral_color_from_signal(state, simple_scene.wb_effect, state.live_signal_num)
                                prepare_overlay_live(state, simple_scene, t, 1.0)
                                return simple_scene.scene
                        end
                elseif state.live_signal_num == STATIC_SIGNAL_NUM then  -- Static picture.
                        return static_scene
                else
                        assert(false)
                end
        end

        -- We do not show overlays on the individual preview inputs.
        -- The M/E preview matches what we'd put live by doing a transition, as always.
        local show_overlay = false
        if num == 1 then  -- Preview.
                if state.preview_signal_num == OVERLAY_SIGNAL_NUM then
                        num = state.live_signal_num + 2
                        show_overlay = not state.overlay_enabled

                        if state.transition_type ~= NO_TRANSITION then
                                num = state.transition_dst_signal + 2
                        end
                else
                        num = state.preview_signal_num + 2
                        show_overlay = state.overlay_enabled and simple_signal_has_overlay(state.preview_signal_num)
                end
        end

        -- Individual preview inputs (usually without overlay).
        if is_plain_signal(num - 2) then
                local signal_num = num - 2
                simple_scene.overlay.overlay_effect:enable_if(show_overlay)
                simple_scene.input:display(signal_num)
                set_scale_parameters_if_needed(simple_scene, signals, signal_num, width, height, false)
                set_neutral_color_from_signal(state, simple_scene.wb_effect, signal_num)
                prepare_overlay_static(simple_scene, t)
                return simple_scene.scene
        end
        if num == SBS_SIGNAL_NUM + 2 then
                sbs_scene.input0.overlay.overlay_effect:enable_if(show_overlay)
                prepare_sbs_scene(state, sbs_scene, 0.0, NO_TRANSITION, 0, SBS_SIGNAL_NUM, width, height, input_resolution, false)
                return sbs_scene.scene
        end
        if num == STATIC_SIGNAL_NUM + 2 then
                return static_scene
        end
        if num == OVERLAY_SIGNAL_NUM + 2 then
                return overlay_scene_lq
        end
end

-- This is broken, of course (even for positive numbers), but Lua doesn't give us access to real rounding.
function round(x)
        return math.floor(x + 0.5)
end

function lerp(a, b, t)
        return a + (b - a) * t
end

function lerp_pos(a, b, t)
        return {
                x0 = lerp(a.x0, b.x0, t),
                y0 = lerp(a.y0, b.y0, t),
                x1 = lerp(a.x1, b.x1, t),
                y1 = lerp(a.y1, b.y1, t)
        }
end

function pos_from_top_left(x, y, width, height, screen_width, screen_height)
        local xs = screen_width / 1280.0
        local ys = screen_height / 720.0
        return {
                x0 = round(xs * x),
                y0 = round(ys * y),
                x1 = round(xs * (x + width)),
                y1 = round(ys * (y + height))
        }
end

function prepare_sbs_scene(state, scene, t, transition_type, src_signal, dst_signal, screen_width, screen_height, input_resolution, hq)
        scene.input0.input:display(0)
        scene.input1.input:display(4)
        set_neutral_color(scene.input0.wb_effect, state.neutral_colors[1])
        set_neutral_color(scene.input1.wb_effect, state.neutral_colors[5])

        -- Both inputs are the same size (true side-by-side).
        local pos0 = pos_from_top_left(1280 - 616 - 16, 186, 616, 347, screen_width, screen_height)
        local pos1 = pos_from_top_left(16, 186, 616, 347, screen_width, screen_height)

        local pos_fs = { x0 = 0, y0 = 0, x1 = screen_width, y1 = screen_height }
        local affine_param
        if transition_type == NO_TRANSITION then
                -- Static SBS view.
                affine_param = { sx = 1.0, sy = 1.0, tx = 0.0, ty = 0.0 }   -- Identity.
        else
                -- Zooming to/from SBS view into or out of a single view.
                assert(transition_type == ZOOM_TRANSITION)
                local signal, real_t
                if src_signal == SBS_SIGNAL_NUM then
                        signal = dst_signal
                        real_t = t
                else
                        assert(dst_signal == SBS_SIGNAL_NUM)
                        signal = src_signal
                        real_t = 1.0 - t
                end

                if signal == INPUT0_SIGNAL_NUM then
                        affine_param = find_affine_param(pos0, lerp_pos(pos0, pos_fs, real_t))
                elseif signal == INPUT4_SIGNAL_NUM then
                        affine_param = find_affine_param(pos1, lerp_pos(pos1, pos_fs, real_t))
                end
        end

        -- NOTE: input_resolution is not 1-indexed, unlike usual Lua arrays.
        place_rectangle_with_affine(scene.input0, pos0, affine_param, screen_width, screen_height, input_resolution[0].width, input_resolution[0].height, hq)
        place_rectangle_with_affine(scene.input1, pos1, affine_param, screen_width, screen_height, input_resolution[1].width, input_resolution[1].height, hq)
end

-- Find the transformation that changes the first rectangle to the second one.
function find_affine_param(a, b)
        local sx = (b.x1 - b.x0) / (a.x1 - a.x0)
        local sy = (b.y1 - b.y0) / (a.y1 - a.y0)
        return {
                sx = sx,
                sy = sy,
                tx = b.x0 - a.x0 * sx,
                ty = b.y0 - a.y0 * sy
        }
end

function place_rectangle_with_affine(input, pos, aff, screen_width, screen_height, input_width, input_height, hq)
        local x0 = pos.x0 * aff.sx + aff.tx
        local x1 = pos.x1 * aff.sx + aff.tx
        local y0 = pos.y0 * aff.sy + aff.ty
        local y1 = pos.y1 * aff.sy + aff.ty

        place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
end

function place_rectangle(input, x0, y0, x1, y1, screen_width, screen_height, input_width, input_height, hq)
        input.padding_effect:set_int("width", screen_width)
        input.padding_effect:set_int("height", screen_height)

        -- Cull.
        if x0 > screen_width or x1 < 0.0 or y0 > screen_height or y1 < 0.0 then
                input.resample_effect:choose(ResizeEffect)  -- Low-quality resizing.
                input.resample_effect:set_int("width", 1)
                input.resample_effect:set_int("height", 1)
                input.padding_effect:set_int("left", screen_width + 100)
                input.padding_effect:set_int("top", screen_height + 100)
                return
        end

        local srcx0 = 0.0
        local srcx1 = 1.0
        local srcy0 = 0.0
        local srcy1 = 1.0

        -- Clip.
        if x0 < 0 then
                srcx0 = -x0 / (x1 - x0)
                x0 = 0
        end
        if y0 < 0 then
                srcy0 = -y0 / (y1 - y0)
                y0 = 0
        end
        if x1 > screen_width then
                srcx1 = (screen_width - x0) / (x1 - x0)
                x1 = screen_width
        end
        if y1 > screen_height then
                srcy1 = (screen_height - y0) / (y1 - y0)
                y1 = screen_height
        end

        if hq then
                -- High-quality resampling.
                local resample_effect = input.resample_effect:choose(ResampleEffect)

                local x_subpixel_offset = x0 - math.floor(x0)
                local y_subpixel_offset = y0 - math.floor(y0)

                -- Resampling must be to an integral number of pixels. Round up,
                -- and then add an extra pixel so we have some leeway for the border.
                local width = math.ceil(x1 - x0) + 1
                local height = math.ceil(y1 - y0) + 1
                input.resample_effect:set_int("width", width)
                input.resample_effect:set_int("height", height)

                -- Correct the discrepancy with zoom. (This will leave a small
                -- excess edge of pixels and subpixels, which we'll correct for soon.)
                local zoom_x = (x1 - x0) / (width * (srcx1 - srcx0))
                local zoom_y = (y1 - y0) / (height * (srcy1 - srcy0))
                resample_effect:set_float("zoom_x", zoom_x)  -- Use the actual effect specialization; specific to ResampleEffect.
                resample_effect:set_float("zoom_y", zoom_y)
                resample_effect:set_float("zoom_center_x", 0.0)
                resample_effect:set_float("zoom_center_y", 0.0)

                -- Padding must also be to a whole-pixel offset.
                input.padding_effect:set_int("left", math.floor(x0))
                input.padding_effect:set_int("top", math.floor(y0))

                -- Correct _that_ discrepancy by subpixel offset in the resampling.
                resample_effect:set_float("left", srcx0 * input_width - x_subpixel_offset / zoom_x)
                resample_effect:set_float("top", srcy0 * input_height - y_subpixel_offset / zoom_y)

                -- Finally, adjust the border so it is exactly where we want it.
                input.padding_effect:set_float("border_offset_left", x_subpixel_offset)
                input.padding_effect:set_float("border_offset_right", x1 - (math.floor(x0) + width))
                input.padding_effect:set_float("border_offset_top", y_subpixel_offset)
                input.padding_effect:set_float("border_offset_bottom", y1 - (math.floor(y0) + height))
        else
                -- Lower-quality simple resizing.
                input.resample_effect:choose(ResizeEffect)

                local width = round(x1 - x0)
                local height = round(y1 - y0)
                input.resample_effect:set_int("width", width)
                input.resample_effect:set_int("height", height)

                -- Padding must also be to a whole-pixel offset.
                input.padding_effect:set_int("left", math.floor(x0))
                input.padding_effect:set_int("top", math.floor(y0))

                -- No subpixel stuff.
                input.padding_effect:set_float("border_offset_left", 0.0)
                input.padding_effect:set_float("border_offset_right", 0.0)
                input.padding_effect:set_float("border_offset_top", 0.0)
                input.padding_effect:set_float("border_offset_bottom", 0.0)
        end
end

function prepare_overlay_live(state, scene, t, extra_alpha_factor)
        if scene.overlay then
                local tt = calc_fade_progress(t, state.overlay_transition_start, state.overlay_transition_end)
                local overlay_alpha = state.overlay_alpha_src + tt * (state.overlay_alpha_dst - state.overlay_alpha_src)
                overlay_alpha = overlay_alpha * extra_alpha_factor
                --print("overlay_alpha=" .. overlay_alpha .. " [" .. state.overlay_alpha_src .. "," .. state.overlay_alpha_dst .. "]@" .. tt)
                if t > state.overlay_transition_end and state.overlay_alpha_dst == 0.0 then
                        state.overlay_enabled = false  -- Takes effect next frame.
        --              print("Turning off overlay")
                end
                scene.overlay.multiply_effect:set_vec4("factor", overlay_alpha, overlay_alpha, overlay_alpha, overlay_alpha)
        end
end

function prepare_overlay_static(scene)
        if scene.overlay then
                scene.overlay.multiply_effect:set_vec4("factor", 1.0, 1.0, 1.0, 1.0)
        end
end

function set_neutral_color(effect, color)
        effect:set_vec3("neutral_color", color[1], color[2], color[3])
end

function set_neutral_color_from_signal(state, effect, signal)
        if is_plain_signal(signal) then
                set_neutral_color(effect, state.neutral_colors[signal - INPUT0_SIGNAL_NUM + 1])
        end
end

function calc_zoom_progress(t)
        if t < state.transition_start then
                return 0.0
        elseif t > state.transition_end then
                return 1.0
        else
                local tt = (t - state.transition_start) / (state.transition_end - state.transition_start)
                -- Smooth it a bit.
                return math.sin(tt * 3.14159265358 * 0.5)
        end
end

function calc_fade_progress(t, transition_start, transition_end)
        local tt = (t - transition_start) / (transition_end - transition_start)
        if tt < 0.0 then
                return 0.0
        elseif tt > 1.0 then
                return 1.0
        end

        -- Make the fade look maybe a tad more natural, by pumping it
        -- through a sigmoid function.
        tt = 10.0 * tt - 5.0
        tt = 1.0 / (1.0 + math.exp(-tt))

        return tt
end

ThemeMenu.set(
        { "Reload overlay", reload_cef },
        { "Disconnect IPTV", disconnect_iptv }
)