Dynamic FPS: WebP/GIF inherit source fps (min 30)

Replaces hardcoded WEBP_FPS=15/GIF_FPS=15 with source_fps() that
reads mf-fps, video-params/fps, or estimated-vf-fps, flooring at 30.

scripts/export-loop-webp.lua

@@ -19,16 +19,26 @@ local OUTPUT_DIR = os.getenv("HOME") .. "/Videos/mpv-loops"
 local GIF_DIR     = OUTPUT_DIR .. "/gif"
 local ENABLE_OSD_MSG = true
 
--- WebP settings
-local WEBP_FPS = 15
+-- Detect source frame rate (handles mf:// from webp-anim-bridge).
+-- Returns at least 30fps.
+local function source_fps()
+    local mf_fps = mp.get_property_number("mf-fps", 0)
+    if mf_fps and mf_fps > 0 then return math.max(30, mf_fps) end
+    local vfps = mp.get_property_number("video-params/fps", 0)
+    if vfps and vfps > 0 then return math.max(30, vfps) end
+    local efps = mp.get_property_number("estimated-vf-fps", 0)
+    if efps and efps > 0 then return math.max(30, efps) end
+    return 30
+end
+
+-- Config — FPS is now dynamic via source_fps(). Fallback minimum for mf:// only.
 local WEBP_QUALITY = 80
 local WEBP_LOSSLESS = false
 local WEBP_MAX_WIDTH = 800
 local WEBP_LOOP = 0
 
 -- GIF settings
-local GIF_FPS = 15
-local GIF_MAX_WIDTH = 800               -- bumped from 600 to match WebP
+local GIF_MAX_WIDTH = 800
 local GIF_DITHER = "bayer"
 local GIF_LOOP = 0
 
@@ -96,10 +106,11 @@ end
 
 -- Build the WebP vf string (fps + optional eq + zoom/pan crop)
 local function build_webp_vf(include_eq)
+    local fps = source_fps()
     local parts = {}
     local crop = zoom_pan_crop()
     if crop then table.insert(parts, crop) end
-    table.insert(parts, string.format("fps=%d", WEBP_FPS))
+    table.insert(parts, string.format("fps=%d", fps))
     if include_eq then
         local eq = build_eq_filter()
         if eq then table.insert(parts, eq) end
@@ -109,10 +120,11 @@ end
 
 -- Build the GIF vf string (fps + optional eq + palettegen/paletteuse + zoom/pan crop)
 local function build_gif_vf(include_eq)
+    local fps = source_fps()
     local parts = {}
     local crop = zoom_pan_crop()
     if crop then table.insert(parts, crop) end
-    table.insert(parts, string.format("fps=%d", GIF_FPS))
+    table.insert(parts, string.format("fps=%d", fps))
     if include_eq then
         local eq = build_eq_filter()
         if eq then table.insert(parts, eq) end
@@ -148,7 +160,7 @@ local function build_ffmpeg_seek_args(a, b)
         if pattern:sub(1, 5) == "mf://" then
             pattern = pattern:sub(6)
         end
-        local mf_fps = mp.get_property_number("mf-fps", 10)
+        local mf_fps = source_fps()
         table.insert(args, "-framerate"); table.insert(args, tostring(mf_fps))
         table.insert(args, "-start_number"); table.insert(args, "0")
         table.insert(args, "-i");           table.insert(args, pattern)