Edit: I don’t know why but specifying the filename of the script-opts file made it work even though the basenames are the same.

Change:

From:

-- Define a table with default options
local o = {
    memory_usage_percentage = 80,
    reserved_memory_gb = 6
}

-- Read the options from the script-opts file
options.read_options(o)

-- Print the read options for debugging purposes
msg.info("memory_usage_percentage: " .. o.memory_usage_percentage)
msg.info("reserved_memory_gb: " .. o.reserved_memory_gb)

To:

-- Define a table with default options
local opts = {
    memory_usage_percentage = 80,
    reserved_memory_gb = 6
}

-- Read the options from the script-opts file
(require 'mp.options').read_options(opts, "demuxer-max-bytes")

-- Print the read options for debugging purposes
msg.info("memory_usage_percentage: " .. opts.memory_usage_percentage)
msg.info("reserved_memory_gb: " .. opts.reserved_memory_gb)

Original post: I am making a lua script to adjust buffer size dynamically based on available ram. The script is working with the hardcoded values: memory_usage_percentage = 80, reserved_memory_gb = 6 but it is not reading the new values from my script-opts file. Do you see why?

cat /home/cmysmiaczxotoy/.config/mpv/script-opts/demuxer-max-bytes.conf

memory_usage_percentage=70
reserved_memory_gb=8

cat /home/cmysmiaczxotoy/.config/mpv/scripts/demuxer-max-bytes.lua (Now edited with fix)

-- Require the necessary modules
local mp = require 'mp'
local msg = require 'mp.msg'

-- Define a table with default options
local opts = {
    memory_usage_percentage = 80,
    reserved_memory_gb = 6
}

-- Read the options from the script-opts file
(require 'mp.options').read_options(opts, "demuxer-max-bytes")

-- Print the read options for debugging purposes
msg.info("memory_usage_percentage: " .. opts.memory_usage_percentage)
msg.info("reserved_memory_gb: " .. opts.reserved_memory_gb)

local function is_windows()
    return package.config:sub(1,1) == '\\'
end

local function set_memory_properties(free_mem_kib, total_mem_kib)
    -- Calculate the percentage of the total memory in KiB
    local allowed_mem_kib = total_mem_kib * (opts.memory_usage_percentage / 100)
    -- Convert reserved memory from GB to KiB
    local reserved_mem_kib = opts.reserved_memory_gb * 1024 * 1024
    -- Calculate the amount of memory to use, leaving the reserved memory free
    local mem_to_use_kib = allowed_mem_kib - (total_mem_kib - free_mem_kib - reserved_mem_kib)

    -- Apply various checks and calculations to mem_to_use_kib
    if mem_to_use_kib > free_mem_kib - reserved_mem_kib then
        mem_to_use_kib = free_mem_kib - reserved_mem_kib
    end
    if mem_to_use_kib < 0 then
        mem_to_use_kib = free_mem_kib - reserved_mem_kib
    end
    if mem_to_use_kib < 0 then
        mem_to_use_kib = 1024
    end

    -- Convert to bytes and round to nearest integer
    local mem_to_use_bytes = math.floor(mem_to_use_kib * 1024)

    -- Set demuxer-max-bytes to the calculated value
    mp.set_property("demuxer-max-bytes", tostring(mem_to_use_bytes))
    mp.msg.info("Set demuxer-max-bytes to: " .. mem_to_use_bytes .. " bytes")
    
    -- Set cache-related properties
    mp.set_property("cache", "yes")
    mp.set_property("cache-pause", "yes")
    mp.set_property("force-seekable", "yes")
    mp.set_property("demuxer-readahead-secs", "30")
end

-- Function to gather memory info on Windows
local function get_memory_info_windows()
    local ps_script = 'Get-CimInstance Win32_OperatingSystem | ' ..
                      'ForEach-Object { $_.FreePhysicalMemory, $_.TotalVisibleMemorySize }'
    local handle = io.popen('powershell -NoProfile -Command "' .. ps_script .. '"', 'r')
    local free_mem_kib = handle:read("*l")
    local total_mem_kib = handle:read("*l")
    handle:close()

    return tonumber(free_mem_kib), tonumber(total_mem_kib)
end

-- Function to gather memory info on Linux
local function get_memory_info_linux()
    local total_mem_kib = 0
    local free_mem_kib = 0
    local meminfo = io.open("/proc/meminfo", "r")
    if meminfo then
        for line in meminfo:lines() do
            local key, value = line:match("(%w+):%s+(%d+)")
            if key == "MemAvailable" then
                free_mem_kib = tonumber(value)
            elseif key == "MemTotal" then
                total_mem_kib = tonumber(value)
            end
        end
        meminfo:close()
    end

    return free_mem_kib, total_mem_kib
end

-- This hook runs at the start of file loading
mp.register_event("start-file", function()
    local free_mem_kib, total_mem_kib

    if is_windows() then
        free_mem_kib, total_mem_kib = get_memory_info_windows()
    else
        free_mem_kib, total_mem_kib = get_memory_info_linux()
    end

    if total_mem_kib > 0 then
        set_memory_properties(free_mem_kib, total_mem_kib)
    else
        mp.msg.error("Could not determine total memory.")
    end
end)