Build a Reddit Video downloader with Python
This article is about building a Reddit video downloader from scratch using python.
I wrote a post on building a YouTube video downloader from scratch some time ago. If you are interested, give it a read.
Reddit makes it tough to download posted videos directly. This is because Reddit saves the audio and video separately on their servers. But this is not a big problem, as we will download both audio and video separately and join them using
How to get the video URL?
Every Reddit post can be parsed as a JSON, simply by appending a
.json to the URL. Thus,
Go to the JSON URL, and you should see something like,
From there, it is easy. Press
Ctrl + F and search for
That's what we need, the
fallback URL. Now have to figure out how to reach here starting from the top.
If you are trying to experiment with this on your own, make sure you either download the JSON or try using
colab. The Reddit rate-limiting feature won't allow you to fetch the JSON data frequently.
First, get the JSON data using
data = requests.get(post_url).json()
post_url is the JSON URL.
Obtain the URL using,
url = data["data"]["children"]["data"]["secure_media"]["reddit_video"][ "fallback_url" ]
This is what a typical video URL looks like,
Not the best approach. Here we didn't even check if the keys existed. We'll assume this is the standard format for all posts.
What about the audio URL?
The audio URL is not available in the JSON data. But it can be obtained using a simple hack.
As mentioned above, this is the video URL. Go to the URL and check if it's video-only.
DASH_1080.mp4 is the filename, where 1080 is the resolution. Replace the resolution with
audio, and you get the audio URL.
Thus the audio URL corresponding to our URL is https://v.redd.it/jvjih3f894b61/DASH_audio.mp4?source=fallback
Now that you have both audio and video, download them in a pythonic way.
import urllib.request urllib.request.urlretrieve( url, filename=output_path, )
If you are a big fan of progress bars, add one using the
reporthook of urlretrieve.
from tqdm import tqdm class DownloadProgressBar(tqdm): def update_to(self, b: int = 1, bsize: int = 1024, tsize: int = None): if tsize is not None: self.total = tsize self.update(b * bsize - self.n) with DownloadProgressBar(unit="B", unit_scale=True, miniters=1) as d: urllib.request.urlretrieve( url, filename=output_path, reporthook=d.update_to, )
Let's merge 'em
Once the files are downloaded to
video.mp4, let's merge them using FFMpeg.
FYI, you can have any name for audio and video output files.
If you don't have FFmpeg installed, download it from here for windows.
sudo apt install ffmpeg
Now run the following to merge them both,
ffmpeg -i video.mp4 -i audio.mp4 -c:v copy -c:a aac output.mp4
It doesn't take more than a few seconds to merge. Once complete, enjoy the video.
In this post, we saw how to download a Reddit video along with its audio using python. There was nothing fancy in this approach; all we had to do was get the URL somehow. If there's a better approach, please do tell.
I went ahead and created a python CLI named
to download a video.
The whole code can be found at