displaying large video files in google colab

Question

the common way to display videos in google colab is like this:

from IPython.display import HTML
from base64 import b64encode
with open('video.mp4', 'rb') as f:
   display(HTML('<video><source src="data:video/mp4;base64,%s" type="video/mp4"></video>'%b64encode(f.read()).decode()))

however for moderately large video files, say tens of MB, this will cause colab to disconnect (showing only "runtime disconnected") and the video will not be displayed. indeed it does not seem sensible to try to write such a long string into the HTML. what would be the easiest fix? note that the HTML does not have access to the local filesystem due to CORS.

Answer 1

There's no need for base64 encoding. You can use ordinary <video> tags to embed.

Here's a complete example: https://colab.research.google.com/drive/1GqZvHmOwGpo9QsrxeEpH93kswgVliQQl

Replicating the code here:

# Download a video file to be served locally.
!wget https://interactive-examples.mdn.mozilla.net/media/cc0-videos/flower.mp4

# Start a webserver in the background, running on port 8000.
%%script bash --bg
python3 -m http.server 8000

# Embed the video file.
%%html
<video controls autoplay><source src="http://localhost:8000/flower.mp4" type="video/mp4"></video>

The result is a typical video embed:

Colab will automatically proxy HTTP requests to locahost from Javascript to the backend VM. More details on why this works are described in the documentation here: https://colab.research.google.com/notebooks/snippets/advanced_outputs.ipynb#scrollTo=R8ZvCXC5A0wT