[postprocessor:ugoira] use 'image2' demuxer (#1550)

Ensures exact frame timecodes with no duplicate frames.

Possible issues are the duration the last frame in an Ugoira with variable
frame durations is shown and insufficient timestamp precision of the
underlying file system (e.g. FAT32, ext3; works on ext4, tmpfs, NTFS).

docs/configuration.rst

@@ -2498,6 +2498,18 @@ Description
     Additional FFmpeg command-line arguments.
 
 
+ugoira.ffmpeg-demuxer
+---------------------
+Type
+    ``string``
+Default
+    ``image2``
+Description
+    FFmpeg demuxer to read input files with. Possible values are
+    "`image2 <https://ffmpeg.org/ffmpeg-formats.html#image2-1>`_" and
+    "`concat <https://ffmpeg.org/ffmpeg-formats.html#concat-1>`_".
+
+
 ugoira.ffmpeg-location
 ----------------------
 Type

gallery_dl/postprocessor/ugoira.py

@@ -34,6 +34,11 @@ class UgoiraPP(PostProcessor):
         if rate != "auto":
             self.calculate_framerate = lambda _: (None, rate)
 
+        if options.get("ffmpeg-demuxer") == "concat":
+            self._process = self._concat
+        else:
+            self._process = self._image2
+
         if options.get("libx264-prevent-odd", True):
             # get last video-codec argument
             vcodec = None
@@ -72,38 +77,17 @@ class UgoiraPP(PostProcessor):
         if not self._frames:
             return
 
-        rate_in, rate_out = self.calculate_framerate(self._frames)
-
         with tempfile.TemporaryDirectory() as tempdir:
             # extract frames
             try:
                 with zipfile.ZipFile(pathfmt.temppath) as zfile:
                     zfile.extractall(tempdir)
             except FileNotFoundError:
-                pathfmt.temppath = pathfmt.realpath
+                pathfmt.realpath = pathfmt.temppath
                 return
 
-            # write ffconcat file
-            ffconcat = tempdir + "/ffconcat.txt"
-            with open(ffconcat, "w") as file:
-                file.write("ffconcat version 1.0\n")
-                for frame in self._frames:
-                    file.write("file '{}'\n".format(frame["file"]))
-                    file.write("duration {}\n".format(frame["delay"] / 1000))
-                if self.extension != "gif":
-                    # repeat the last frame to prevent it from only being
-                    # displayed for a very short amount of time
-                    file.write("file '{}'\n".format(self._frames[-1]["file"]))
-
-            # collect command-line arguments
-            args = [self.ffmpeg]
-            if rate_in:
-                args += ("-r", str(rate_in))
-            args += ("-i", ffconcat)
-            if rate_out:
-                args += ("-r", str(rate_out))
-            if self.prevent_odd:
-                args += ("-vf", "crop=iw-mod(iw\\,2):ih-mod(ih\\,2)")
+            # process frames and collect command-line arguments
+            args = self._process(tempdir)
             if self.args:
                 args += self.args
             self.log.debug("ffmpeg args: %s", args)
@@ -112,7 +96,7 @@ class UgoiraPP(PostProcessor):
             pathfmt.set_extension(self.extension)
             try:
                 if self.twopass:
-                    if "-f" not in args:
+                    if "-f" not in self.args:
                         args += ("-f", self.extension)
                     args += ("-passlogfile", tempdir + "/ffmpeg2pass", "-pass")
                     self._exec(args + ["1", "-y", os.devnull])
@@ -131,6 +115,45 @@ class UgoiraPP(PostProcessor):
                 else:
                     pathfmt.set_extension("zip")
 
+    def _concat(self, path):
+        # write ffconcat file
+        ffconcat = path + "/ffconcat.txt"
+        with open(ffconcat, "w") as file:
+            file.write("ffconcat version 1.0\n")
+            for frame in self._frames:
+                file.write("file '{}'\n".format(frame["file"]))
+                file.write("duration {}\n".format(frame["delay"] / 1000))
+            if self.extension != "gif":
+                # repeat the last frame to prevent it from only being
+                # displayed for a very short amount of time
+                file.write("file '{}'\n".format(frame["file"]))
+
+        rate_in, rate_out = self.calculate_framerate(self._frames)
+        args = [self.ffmpeg, "-f", "concat"]
+        if rate_in:
+            args += ("-r", str(rate_in))
+        args += ("-i", ffconcat)
+        if rate_out:
+            args += ("-r", str(rate_out))
+        return args
+
+    def _image2(self, path):
+        path += "/"
+
+        # adjust frame mtime values
+        ts = 0
+        for frame in self._frames:
+            os.utime(path + frame["file"], ns=(ts, ts))
+            ts += frame["delay"] * 1000000
+
+        return [
+            self.ffmpeg,
+            "-f", "image2",
+            "-ts_from_file", "2",
+            "-pattern_type", "sequence",
+            "-i", path.replace("%", "%%") + "%06d.jpg",
+        ]
+
     def _exec(self, args):
         out = None if self.output else subprocess.DEVNULL
         return subprocess.Popen(args, stdout=out, stderr=out).wait()