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ytdl-org / youtube-dl

Command-line program to download videos from YouTube.com and other video sites
http://ytdl-org.github.io/youtube-dl/
The Unlicense
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Freezing #648

Closed novasharper closed 11 years ago

novasharper commented 11 years ago

Whenever youtube-dl has a hight download speed, it always freezes and drops down to a very low download speed (~70k/s). I don't understand why this happens. It is a relatively new problem. It did not appear in older builds. The problem started sometime around the 10th.

phihag commented 11 years ago

That's most likely youtube and not youtube-dl, which is always experimenting with high transfer speeds.

In any case, I'm not aware of any downloading or bandwidth management changes. Can you reproduce the problem with an older version? If so, can you give me two pcap files that show it? Otherwise, I don't see a way to diagnose the problem.

novasharper commented 11 years ago

Ok. I will try that.

On 1/23/2013 5:04 PM, Philipp Hagemeister wrote:

That's most likely youtube and not youtube-dl, which is always experimenting with high transfer speeds.

In any case, I'm not aware of any downloading or bandwidth management changes. Can you reproduce the problem with an older version? If so, can you give me two pcap files that show it? Otherwise, I don't see a way to diagnose the problem.

— Reply to this email directly or view it on GitHub https://github.com/rg3/youtube-dl/issues/648#issuecomment-12625240.

marcusbarbu commented 11 years ago

I am having the same issue. Download speed starts at 1.8 mb/s (high/normal for my connection), the program hangs for a moment and then progressively drops before hitting ~65 kb/s.

FiloSottile commented 11 years ago

Discussion in #355 is relevant.

Today I noticed a thing: in the player the speed is really high for the first buffering seconds, then drops to about playing speed, BUT if you seek to a point near the end of the buffer the speed bursts again.

I'm not really sure we can/should exploit this but it's interesting.

Plaque-fcc commented 11 years ago 
This certainly appears to be about server-to-client stream

shaping. Can you make server stream it to you again fullspeed? Yeah, just break the connection up. Playing with wget (direct http-download) on video streaming servers, one can notice the same thing.

To reproduce:

• use youtube-dl to fetch direct link to the video; • ask youtube-dl on its user-agent string; • run wget with the link and fake user-agent string.

You will notice all the same: 3-10 sec boost then streaming about the bitrate of the movie you are fetching. Interrupt the download and start it again (use «-c» wget switch to resume download) — and in 5-10 cycles of doing so you receive the overhead enough to feed your media player, depending on the movie's file size.

FiloSottile commented 11 years ago

Aaaaaand... closed! Really. With a60b854, it was easy :sparkles:

:boom: Now you can effectively download the whole video at the maximum speed of your connection.

Is it safe to say that this makes us the fastest YT downloader around? (And that we will get in trouble with Google? :smirk:)

stolendog commented 11 years ago

is it really works? because using last version 2013.05.07 I am getting download rate drop, using -f 34 format. This problem can be solved only when using -f 43 format (WebM).

rg3 commented 11 years ago

This was reverted in commit c8c5443bb50644bfd784044860092f95cb4616b5 because apparently it broke a lot of videos.

FiloSottile commented 11 years ago

Crossing my fingers.

marcusbarbu commented 11 years ago

Just tried it, everything seems to work as far as download speed.