Youtube Download Slows Down after 10 seconds

[phil2508]

Tried this on 4 different machines, two Suse, one Ubuntu, one Mac. The same problem on every environment: Download starts with about 800kb/s but slows down to 200kb/s after about 10 seconds and then drifts all the way down to 50-80kb/s. Videos that are 3 minutes or longer take forever to download. Can this be fixed?

[rg3]

This is due to YouTube limiting the download speed server-side to
approximately match the video streaming needs.

[jcarlosgarciasegovia]

@rg3 So, why did you not close this issue?

[rg3]

I'm not the current maintainer, so I don't close issues. :)

[phihag]

In my (non-scientific) experience, youtube may send videos with a constant fast speed if you don't run into any congestion at all (i.e. with a 100MBit/s link). Since the same seems to apply to videos in the web browser as well, I don't think there's anything we can do about it.

[phil2508]

Tried this on a 200Mb/s connection and same slow down happening. Bummer. Would be interesting to get best practices on which format has the best speed/quality ratio.

[phil2508]

Ok, after some research it seems like the solution is multi-threading. Other (mostly desktop tools) use that technique to speed up the download process and trick Youtube that way.

Should I post this as a feature request??

[rbrito]

Downloading the videos with external downloaders (like my branch that passes the videos to aria2c) mitigate this issue (I open 4 parallel connections at a time). Nota bene: mitigates, but doesn't solve.

[hickford]

I have this issue too.

[phil2508]

Can you make this available?
On Aug 9, 2012 12:57 AM, "Rogério Brito" notifications@github.com wrote:

Downloading the videos with external downloaders (like my branch that
passes the videos to aria2c) mitigate this issue (I open 4 parallel
connections at a time). Nota bene: mitigates, but doesn't solve.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/355#issuecomment-7607737.

[LouisPlisso]

Nowadays, YouTube sends the first 40 seconds of video at maximum rate, and then limits the throughput of the connection.
You can find the details (it depends on the browser...) here: http://www-sop.inria.fr/members/Chadi.Barakat/CONEXT2011.pdf

[rbrito]

@phil2508, you can see the aria2c downloading that I mentioned at #182

[gettalong]

Using -f 43 works for me for fast downloads, ie. I download with roughly 100MBit which is my network speed.

[phil2508]

I ended up using AXEL at 23 threads in parallel. I get 200 MB/s at times

[rbrito]

@phil2508, I'm surprised that they didn't start rejecting your connections. Using aria2c with only 4 concurrent connections, I surely did see my connections being rejected and the use of only 1 thread.

Another thing that I observed was that if a given video is available in HD, then they didn't throttle the download and I could get my downloads as fast as my pipe allowed, compared to if I use --max-quality set to, say, 35.

[NoahY]

-f 43 fixed it for me, thanks :)

[mpenkov]

For the record, -f 43 downloads the video in Google's WebM format (VP8 video, Orbis audio). It's a faster download, but also different to what YouTube would normally serve (H.264 video, mp3 audio, if I'm not mistaken).

[corwin-of-amber]

Can someone explain what the -f flag does? I looked at the source and there is a flag -q but it looks as if -f should not even be valid, but it is! Losing my mind here. Pls help.

[Hrxn]

https://github.com/rg3/youtube-dl#format-selection

[SalimF]

I know this is bit old bu I manged to get full speed using external downloaded

youtube-dl -f http-480 http://www.dailymotion.com/video/ --external-downloader axel --external-downloader-args " -U 'Mozilla' -o out.ts -n 16"