title: MoviePy, using a gif as an ImageClip?
body: <p>Using a gif inside an ImageClip doesn't work, is it a normal behavior?</p>
  <h1>The code</h1>
  <pre><code>#!/usr/bin/env python
  from moviepy.editor import *
  
  video = VideoFileClip('./video.mp4')
  watermark = (ImageClip(&quot;./my.gif&quot;)
                          .set_duration(10))
  
  watermaked = CompositeVideoClip([video, watermark], size=video.size)
  watermaked.write_videofile('./gif_output.mp4', fps=30, threads=1)
  </code></pre>
  <p>.</p>
  <h1>The error</h1>
  <pre><code>ValueError: could not broadcast input array from shape (150,150) into shape (150,150,3)
  </code></pre>
  <p>.</p>
  <h1>The stack error</h1>
  <pre><code>Traceback (most recent call last):
    File &quot;./gif_test.py&quot;, line 9, in &lt;module&gt;
      watermaked.write_videofile('./gif_output.mp4', fps=30, threads=1)
    File &quot;&lt;decorator-gen-51&gt;&quot;, line 2, in write_videofile
    File &quot;/Library/Python/2.7/site-packages/moviepy/decorators.py&quot;, line 54, in requires_duration
      return f(clip, *a, **k)
    File &quot;&lt;decorator-gen-50&gt;&quot;, line 2, in write_videofile
    File &quot;/Library/Python/2.7/site-packages/moviepy/decorators.py&quot;, line 137, in use_clip_fps_by_default
      return f(clip, *new_a, **new_kw)
    File &quot;&lt;decorator-gen-49&gt;&quot;, line 2, in write_videofile
    File &quot;/Library/Python/2.7/site-packages/moviepy/decorators.py&quot;, line 22, in convert_masks_to_RGB
      return f(clip, *a, **k)
    File &quot;/Library/Python/2.7/site-packages/moviepy/video/VideoClip.py&quot;, line 349, in write_videofile
      progress_bar=progress_bar)
    File &quot;/Library/Python/2.7/site-packages/moviepy/video/io/ffmpeg_writer.py&quot;, line 209, in ffmpeg_write_video
      fps=fps, dtype=&quot;uint8&quot;):
    File &quot;/Library/Python/2.7/site-packages/tqdm/_tqdm.py&quot;, line 833, in __iter__
      for obj in iterable:
    File &quot;/Library/Python/2.7/site-packages/moviepy/Clip.py&quot;, line 475, in generator
      frame = self.get_frame(t)
    File &quot;&lt;decorator-gen-14&gt;&quot;, line 2, in get_frame
    File &quot;/Library/Python/2.7/site-packages/moviepy/decorators.py&quot;, line 89, in wrapper
      return f(*new_a, **new_kw)
    File &quot;/Library/Python/2.7/site-packages/moviepy/Clip.py&quot;, line 95, in get_frame
      return self.make_frame(t)
    File &quot;/Library/Python/2.7/site-packages/moviepy/video/compositing/CompositeVideoClip.py&quot;, line 110, in make_frame
      f = c.blit_on(f, t)
    File &quot;/Library/Python/2.7/site-packages/moviepy/video/VideoClip.py&quot;, line 611, in blit_on
      return blit(img, picture, pos, mask=mask, ismask=self.ismask)
    File &quot;/Library/Python/2.7/site-packages/moviepy/video/tools/drawing.py&quot;, line 45, in blit
      new_im2[yp1:yp2, xp1:xp2] = blitted
  ValueError: could not broadcast input array from shape (150,150) into shape (150,150,3) 
  </code></pre>