initial commit and version 1.0

moviepy/video/tools/subtitles.py

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+"""Experimental module for subtitles support."""
+
+import re
+
+import numpy as np
+
+from moviepy.decorators import convert_path_to_string
+from moviepy.tools import convert_to_seconds
+from moviepy.video.VideoClip import TextClip, VideoClip
+
+
+class SubtitlesClip(VideoClip):
+    """A Clip that serves as "subtitle track" in videos.
+
+    One particularity of this class is that the images of the
+    subtitle texts are not generated beforehand, but only if
+    needed.
+
+    Parameters
+    ----------
+
+    subtitles
+        Either the name of a file as a string or path-like object, or a list
+
+    font
+        Path to a font file to be used. Optional if make_textclip is provided.
+
+    make_textclip
+        A custom function to use for text clip generation. If None, a TextClip
+        will be generated.
+
+        The function must take a text as argument and return a VideoClip
+        to be used as caption
+
+    encoding
+        Optional, specifies srt file encoding.
+        Any standard Python encoding is allowed (listed at
+        https://docs.python.org/3.8/library/codecs.html#standard-encodings)
+
+    Examples
+    --------
+
+    .. code:: python
+
+        from moviepy.video.tools.subtitles import SubtitlesClip
+        from moviepy.video.io.VideoFileClip import VideoFileClip
+        generator = lambda text: TextClip(text, font='./path/to/font.ttf',
+                                        font_size=24, color='white')
+        sub = SubtitlesClip("subtitles.srt", make_textclip=generator, encoding='utf-8')
+        myvideo = VideoFileClip("myvideo.avi")
+        final = CompositeVideoClip([clip, subtitles])
+        final.write_videofile("final.mp4", fps=myvideo.fps)
+
+    """
+
+    def __init__(self, subtitles, font=None, make_textclip=None, encoding=None):
+        VideoClip.__init__(self, has_constant_size=False)
+
+        if not isinstance(subtitles, list):
+            # `subtitles` is a string or path-like object
+            subtitles = file_to_subtitles(subtitles, encoding=encoding)
+
+        # subtitles = [(map(convert_to_seconds, times), text)
+        #              for times, text in subtitles]
+        self.subtitles = subtitles
+        self.textclips = dict()
+
+        self.font = font
+
+        if make_textclip is None:
+            if self.font is None:
+                raise ValueError("Argument font is required if make_textclip is None.")
+
+            def make_textclip(txt):
+                return TextClip(
+                    font=self.font,
+                    text=txt,
+                    font_size=24,
+                    color="#ffffff",
+                    stroke_color="#000000",
+                    stroke_width=1,
+                )
+
+        self.make_textclip = make_textclip
+        self.start = 0
+        self.duration = max([tb for ((ta, tb), txt) in self.subtitles])
+        self.end = self.duration
+
+        def add_textclip_if_none(t):
+            """Will generate a textclip if it hasn't been generated asked
+            to generate it yet. If there is no subtitle to show at t, return
+            false.
+            """
+            sub = [
+                ((text_start, text_end), text)
+                for ((text_start, text_end), text) in self.textclips.keys()
+                if (text_start <= t < text_end)
+            ]
+            if not sub:
+                sub = [
+                    ((text_start, text_end), text)
+                    for ((text_start, text_end), text) in self.subtitles
+                    if (text_start <= t < text_end)
+                ]
+                if not sub:
+                    return False
+            sub = sub[0]
+            if sub not in self.textclips.keys():
+                self.textclips[sub] = self.make_textclip(sub[1])
+
+            return sub
+
+        def frame_function(t):
+            sub = add_textclip_if_none(t)
+            return self.textclips[sub].get_frame(t) if sub else np.array([[[0, 0, 0]]])
+
+        def make_mask_frame(t):
+            sub = add_textclip_if_none(t)
+            return self.textclips[sub].mask.get_frame(t) if sub else np.array([[0]])
+
+        self.frame_function = frame_function
+        hasmask = bool(self.make_textclip("T").mask)
+        self.mask = VideoClip(make_mask_frame, is_mask=True) if hasmask else None
+
+    def in_subclip(self, start_time=None, end_time=None):
+        """Returns a sequence of [(t1,t2), text] covering all the given subclip
+        from start_time to end_time. The first and last times will be cropped so as
+        to be exactly start_time and end_time if possible.
+        """
+
+        def is_in_subclip(t1, t2):
+            try:
+                return (start_time <= t1 < end_time) or (start_time < t2 <= end_time)
+            except Exception:
+                return False
+
+        def try_cropping(t1, t2):
+            try:
+                return max(t1, start_time), min(t2, end_time)
+            except Exception:
+                return t1, t2
+
+        return [
+            (try_cropping(t1, t2), txt)
+            for ((t1, t2), txt) in self.subtitles
+            if is_in_subclip(t1, t2)
+        ]
+
+    def __iter__(self):
+        return iter(self.subtitles)
+
+    def __getitem__(self, k):
+        return self.subtitles[k]
+
+    def __str__(self):
+        def to_srt(sub_element):
+            (start_time, end_time), text = sub_element
+            formatted_start_time = convert_to_seconds(start_time)
+            formatted_end_time = convert_to_seconds(end_time)
+            return "%s - %s\n%s" % (formatted_start_time, formatted_end_time, text)
+
+        return "\n\n".join(to_srt(sub) for sub in self.subtitles)
+
+    def match_expr(self, expr):
+        """Matches a regular expression against the subtitles of the clip."""
+        return SubtitlesClip(
+            [sub for sub in self.subtitles if re.findall(expr, sub[1]) != []]
+        )
+
+    def write_srt(self, filename):
+        """Writes an ``.srt`` file with the content of the clip."""
+        with open(filename, "w+") as file:
+            file.write(str(self))
+
+
+@convert_path_to_string("filename")
+def file_to_subtitles(filename, encoding=None):
+    """Converts a srt file into subtitles.
+
+    The returned list is of the form ``[((start_time,end_time),'some text'),...]``
+    and can be fed to SubtitlesClip.
+
+    Only works for '.srt' format for the moment.
+    """
+    times_texts = []
+    current_times = None
+    current_text = ""
+    with open(filename, "r", encoding=encoding) as file:
+        for line in file:
+            times = re.findall("([0-9]*:[0-9]*:[0-9]*,[0-9]*)", line)
+            if times:
+                current_times = [convert_to_seconds(t) for t in times]
+            elif line.strip() == "":
+                times_texts.append((current_times, current_text.strip("\n")))
+                current_times, current_text = None, ""
+            elif current_times:
+                current_text += line
+    return times_texts