From 136b7d40b502053acef2d7247a5274a0681f5aa2 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Mike=20F=C3=A4hrmann?= <mike_faehrmann@web.de>
Date: Wed, 11 Feb 2026 12:03:06 +0100
Subject: [PATCH] [pp:ugoira] fix processing '.gif' frames

use 'concat' demuxer to combine frames for mkvmerge
https://github.com/danbooru/danbooru/pull/6103
https://github.com/danbooru/danbooru/pull/6241
---
 gallery_dl/postprocessor/ugoira.py | 23 +++++++++++++----------
 test/results/pixiv.py              | 14 +++++++++++++-
 2 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/gallery_dl/postprocessor/ugoira.py b/gallery_dl/postprocessor/ugoira.py
index 3813faec..d3aa0d2e 100644
--- a/gallery_dl/postprocessor/ugoira.py
+++ b/gallery_dl/postprocessor/ugoira.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2018-2025 Mike Fährmann
+# Copyright 2018-2026 Mike Fährmann
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 2 as
@@ -352,14 +352,13 @@ class UgoiraPP(PostProcessor):
 
     def _process_mkvmerge(self, pathfmt, tempdir):
         self._realpath = pathfmt.realpath
-        pathfmt.realpath = tempdir + "/temp." + self.extension
+        pathfmt.realpath = f"{tempdir}/temp.{self.extension}"
 
         return [
             self.ffmpeg,
-            "-f", "image2",
-            "-pattern_type", "sequence",
-            "-i", (f"{tempdir.replace('%', '%%')}/%06d."
-                   f"{self._frames[0]['file'].rpartition('.')[2]}"),
+            "-r", "25",
+            "-f", "concat",
+            "-i", self._write_ffmpeg_concat(tempdir, False),
         ]
 
     def _finalize_mkvmerge(self, pathfmt, tempdir):
@@ -375,12 +374,16 @@ class UgoiraPP(PostProcessor):
         pathfmt.realpath = self._realpath
         self._exec(args)
 
-    def _write_ffmpeg_concat(self, tempdir):
+    def _write_ffmpeg_concat(self, tempdir, duration=True):
         content = ["ffconcat version 1.0"]
 
-        for frame in self._frames:
-            content.append(f"file '{frame['file']}'\n"
-                           f"duration {frame['delay'] / 1000}")
+        if duration:
+            for frame in self._frames:
+                content.append(f"file '{frame['file']}'\n"
+                               f"duration {frame['delay'] / 1000}")
+        else:
+            for frame in self._frames:
+                content.append(f"file '{frame['file']}'")
         if self.repeat:
             content.append(f"file '{frame['file']}'")
         content.append("")
diff --git a/test/results/pixiv.py b/test/results/pixiv.py
index c65dcf94..09f216ea 100644
--- a/test/results/pixiv.py
+++ b/test/results/pixiv.py
@@ -276,7 +276,7 @@ __tests__ = (
 
 {
     "#url"     : "https://www.pixiv.net/artworks/101003492",
-    "#comment" : "original ugoira frames (#6056)",
+    "#comment" : "ugoira - original '.png' frames (#6056)",
     "#class"   : pixiv.PixivWorkExtractor,
     "#options" : {"ugoira": "original"},
     "#results" : (
@@ -292,6 +292,18 @@ __tests__ = (
     "count" : 6,
 },
 
+{
+    "#url"     : "https://www.pixiv.net/en/artworks/108469527",
+    "#comment" : "ugoira - '.gif' frames",
+    "#class"   : pixiv.PixivWorkExtractor,
+    "#options" : {"ugoira": "original"},
+    "#pattern" : r"https://i\.pximg\.net/img\-original/img/2023/05/27/02/23/48/108469527_ugoira\d+\.gif",
+    "#count"   : 30,
+
+    "frames": list,
+    "count" : 30,
+},
+
 {
     "#url"     : "https://www.pixiv.net/artworks/966412",
     "#comment" : "related works (#1237)",