1285856 - Firefox downloads excessive data streaming video from archive.org

Status: RESOLVED INCOMPLETE

(Core :: Audio/Video: Playback, defect, P1)

Description

[Juan R.D. Silva]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:47.0) Gecko/20100101 Firefox/47.0
Build ID: 20160629103935

Steps to reproduce:

Firefox 47.0.1 in Debian Jessie from Mozilla Debian Team.

1. Have any local network traffic monitoring tool running.

2. Go to https://archive.org/details/SoylentGreen1973/ (any other video would do). Note the source file size. In this particular case it was 919.8 MB for MPEG4 file.

3. Click to "Start" arrow to start streaming in default HTML5 in default (low) resolution.

4. Let movie complete.

5. Observe amount of data downloaded in your local network traffic tool. 


Actual results:

In my case the total data downloaded to my computer after completion of the movie was 6.302 GB (vs. 919.8 MB of original movie size).


Expected results:

I expected Firefox to download data comparable in size with the size of the source file.

I immediately streamed the same movie from the same web page with Google Chrome and after completion of the movie the data downloaded to my computer was only 1.043 GB, which is approximately equal to original movie size) and over 6 times less than with Firefox.

Comment 1

[Loic]

I tried with a video less "heavy" like https://archive.org/details/sudden_birth
For 131 MB, FF47 downloaded ~170 MB, that sounds normal.

Comment 2

[Juan R.D. Silva]

Loic, your test does not make sense. 

The problem showed up while plying much larger file. And the whole point is that Firefox poorly managed its cache which obviously resulted in prefetching the same data multiple times, WHILE PLAYING A LARGE FILE.

BTW, my Firefox uses default "automatically manage cache" option. And yours?

Comment 3

[Juan R.D. Silva]

Watched another movie (quite abominable BTW): https://archive.org/details/Frantic1988 The size of original MPEG4 is 696.7M. The movie length is about 1h 59min. Firefox downloaded in total 3.3GB of data. That is near 5 times over the original file.

I wonder if this could be the root of the problem: while watching the movie I paused it several times for about 10-15 minutes each time.

Yesterday I watched another one without pausing and the problem did not show up. It looks like if I pausing the stream, Firefox a kind of times out, discards its cache, and then re-downloads the entire movie again and again.

Comment 4

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Chris - what do you make of this?

Comment 5

[Chris Pearce [:cpearce (Not reading bugmail)]]

Probably the next step would be for someone to repro with NSPR_LOG_MODULES=MediaCache:5,MediaResource:5 and then go through the log carefully to figure out why we're doing what we're doing. Comparing against the layout of the samples in the file.

Comment 6

[Manfred.Steiner]

I have seen a similar problem when playing a video from an OwnCloud system.

When starting the video by one click on the video link, video starts playing and server data traffic is significantly increased.
When pausing the video or closing the video windows, server data traffics stays on same level. That means, Firefox continues downloading the video from the cloud, although nothing is visible on the client.

This may be a serious problem for people with limited data volume internet access, also for server with low bandwidth.

Google Chrome shows the correct behaviour. Downloading stops after pausing or closing the video.

Comment 7

[JW Wang [:jwwang] [:jw_wang]]

Hi Juan,

1. Can you try the latest to see if the issue is still present?
2. Did you have only one page opened while playing the video?
3. What's your OS? Is it Ubuntu? I want to have a test build for you to do more tests to clarify the problem.

Thanks.

Comment 8

[JW Wang [:jwwang] [:jw_wang]]

Been inactive for a while. Please reopen it when there is new findings.

Comment 9

[JW Wang [:jwwang] [:jw_wang]]

clean ni? per comment 8.