1167932 - Nightly hangs when watching Youtube videos

Status: RESOLVED DUPLICATE of bug 1163227

(Core :: Audio/Video, defect)

Description

[Fanolian]

User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:41.0) Gecko/20100101 Firefox/41.0
Build ID: 20150523030206

Steps to reproduce:

1. Start a new session of Nightly, preferably in a new profile.
2. Load https://www.youtube.com/watch?v=2X5x2dJ3Y2g, make sure it plays in HTML5 instead of Flash.
3. Switch quality to 720p, make the video full screen, allow full screen, close ads when it appears.
4. Do not skip the video. Stop moving the mouse until the hang occurs


Actual results:

There are 2 possible outcomes, both occur at around 0:54~1:00 mark of the video:

A: Nightly hangs completely. I can press Esc once to exit full screen video, but then I cannot interact with any of the UI, including closing Nightly. I can only terminate Plugin Container in Task Manager to restore the tabs, if there are other tabs present.

or 
B1: Nightly does not hang but the video stops playing.
B2: All buffered video is lost. Youtube stops buffering too.
B3: I cannot resume playback at the current position by pressing the play button. However, I can skip backward or forward to resume playback instantly.


Result from mozregression-
Nightly:
Last good revision: 35918b0441b4 (2015-05-18)
First bad revision: 4fb7ff694bf5 (2015-05-19)
Pushlog:
https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=35918b0441b4&tochange=4fb7ff694bf5

Inbound:
Last good revision: 4604104f73a8
First bad revision: def08fced852
Pushlog:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=4604104f73a8&tochange=def08fced852


Notes:
1. If I move the mouse around when watching the video, Nightly tends not to hang but stops the video instead.
2. If it does not hang/stop after 1:10 mark, you can assume the issue cannot be reproduced for that try.
3. There are other reports with similar issues recently, e.g. bug 1167928, bug 1167898, bug 1166199, bug 1167061

My Graphics information in about:support
Graphics
--------
Adapter Description: NVIDIA GeForce GTX 760
Adapter Description (GPU #2): Intel(R) HD Graphics 4600
Adapter Drivers: nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um
Adapter Drivers (GPU #2): igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32
Adapter RAM: 4095
Adapter RAM (GPU #2): Unknown
Asynchronous Pan/Zoom: none
ClearType Parameters: D [ Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 100 ] D [ Gamma: 2400 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 100 ]
Device ID: 0x1187
Device ID (GPU #2): 0x0412
Direct2D Enabled: true
DirectWrite Enabled: true (6.3.9600.17795)
Driver Date: 5-11-2015
Driver Date (GPU #2): 3-16-2015
Driver Version: 9.18.13.5286
Driver Version (GPU #2): 10.18.14.4170
GPU #2 Active: false
GPU Accelerated Windows: 1/1 Direct3D 11 (OMTC)
Subsys ID: 282b1462
Subsys ID (GPU #2): 0000000c
Supports Hardware H264 Decoding: true
Vendor ID: 0x10de
Vendor ID (GPU #2): 0x8086
WebGL Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 760 Direct3D11 vs_5_0 ps_5_0)
windowLayerManagerRemote: true
AzureCanvasBackend: direct2d 1.1
AzureContentBackend: direct2d 1.1
AzureFallbackCanvasBackend: cairo
AzureSkiaAccelerated: 0

Comment 1

[Fanolian]

Toggling media.mediasource.format-reader.mp4 to false somehow fixes that:

1. Nightly does not hang. Video does not stop playing at the supposed time position (0:54~1:00, mostly 0:56)
2. The video loads for a split second at the supposed time position, even though buffer is not lost.

Toggling media.format-reader.mp4 does not make a difference.