frameserver

frameserver is a utility for efficiently serving randomly-accessed frames in a video.

Setup

First, install Docker, Python 2.7, and pip.

$ git clone https://github.com/scanner-research/frameserver
$ cd frameserver
$ pip install docker-compose
$ docker-compose pull
$ docker-compose up -d

This spawns a server on port 7500 listening for frame requests.

Example

Here's an example of using the Python requests library to get a frame. Look at the example.py script. We get frame 1300 at 1/2 scale from the video example.mp4.

To run this file, from inside the root of this repository, run:

$ pip install youtube-dl requests
$ youtube-dl "https://www.youtube.com/watch?v=dQw4w9WgXcQ" -f mp4 -o example.mp4
$ python example.py

This generates a file example.jpg which you can scp/open.

Usage

The server exposes the GET endpoint /fetch. This takes the following arguments:

• path (required, string): absolute path (if local) or bucket-relative path (if cloud) to the video
• frame (required, integer): number of the frame in the video to retrieve
• scale (optional, float): relative size to change the image (2.0 is twice as big, 0.5 is half as big)
• height (optional, integer): target height to rescale the image to (keeps width proportional, i.e. maintains aspect ratio)

It returns a JPEG binary image if successful, and a plain text Python traceback on failure.