1180983 - YouTube video failed to buffer/play after pre-roll ad/commercial with slow connection speed/"limited bandwidth"

Status: VERIFIED INCOMPLETE

(Core :: Audio/Video: Playback, defect, P2)

Description

[Stephen Donner [:stephend] Not actively reading bugmail]

Build ID: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:42.0) Gecko/20100101 Firefox/42.0
Built from: https://hg.mozilla.org/mozilla-central/rev/cef11c3e86c3

Screencast: http://screencast.com/t/gEGkmPNf1 (sorry, yes: it's in Flash) :-\

Steps to Reproduce:

1. Find a 4K-enabled video and load/play until you get a lengthy pre-play commercial (2-4 minutes or so?) - when I caught this, it was on https://www.youtube.com/watch?v=PVn2p6uiNog, but I'm not sure there's anything particularly special about that video itself
2. Leave the bitrate at "Auto" for a bit - in my case, I was seeing YouTube say my connection speed was as low as 51kbps (!) - this was during the pre-roll ad
3. After a minute or so, I changed the bitrate to 2160p (4K)
4. Let the ad continue playing; again, in my particular instance, the highest "connection speed" YouTube detected was 86kbps before I quit, to file this bug
5. Wait for the ad to finish playing

(In retrospect, it looks like perhaps I should've waited longer, as I now see -- or so I think -- that, according to YouTube, I didn't even have enough bandwidth to play the lowest-bitrate/encoding of the video?)

Actual Results:

* After the ad finished, my connection speed "climbed" from 51kbps -> 86kbps
* Changing from 4K -> "Auto" didn't seem to work/finish buffering/load the video
* The AJAX-loading image just kept going, although GETs to thumbnails worked (albeit a bit slowly)

I'll attach and/or link to all the logs, next.

Comment 1

[Stephen Donner [:stephend] Not actively reading bugmail]

Log files (with: NSPR_LOG_MODULES=MediaDecoder:5,MediaSource:5,nsMediaElement:5,nsMediaElementEvents:5,mediaPromise:5,MediaFormatReader:5 set):

1) MediaLog.txt (it's 1GB+ - sorry, but I wasn't sure the relevant bits) - https://drive.google.com/a/mozilla.com/file/d/0B_gOai245yuJV0xfVThfbzVGX2c/view?usp=sharing
2) about-media-5-19pm.txt - https://drive.google.com/a/mozilla.com/file/d/0B_gOai245yuJNmoxR0lTYjktUWc/view?usp=sharing
3) about-media-5-20pm.txt - https://drive.google.com/a/mozilla.com/file/d/0B_gOai245yuJZUhPcEJiTzdiaWc/view?usp=sharing
4) about-media-5-21pm.txt - https://drive.google.com/a/mozilla.com/file/d/0B_gOai245yuJWjFEWHpVNUZ2WUU/view?usp=sharing

Comment 2

[Ralph Giles (:rillian)]

What network was this on? Mozilla's in Mountain View? We're wondering if it's a known ipv6 issue.

Also, can you still reproduce?

Comment 3

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to Ralph Giles (:rillian) from comment #2)
> What network was this on? Mozilla's in Mountain View? We're wondering if
> it's a known ipv6 issue.

Yes, corporate LAN (not Wi-Fi), and I have to mention that at least once,  I had seen the same issue with Chrome (Canary build); sorry for not reporting back with that info :-(

> Also, can you still reproduce?

I'll try again tonight when I get some freed-up time, hopefully, but given that it happened with Chrome, too, I wonder if it's worth it?

Comment 4

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

I'm going to close this on the basis that it is the same on Chrome and Firefox so is likely a network issue.

Comment 5

[Stephen Donner [:stephend] Not actively reading bugmail]

(In reply to Anthony Jones (:kentuckyfriedtakahe, :k17e) from comment #4)
> I'm going to close this on the basis that it is the same on Chrome and
> Firefox so is likely a network issue.

Thanks; verified.  I haven't seen this since, and I run nightly.