User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/38.0.2125.101 Safari/537.36 Steps to reproduce: Go to YouTube or any other website where videos are played (incl. cnn.com). Play video. Actual results: Video playback / streaming is choppy. Video frames are missed (a bit like an old movie). Video lags sound by about 0.5s to 1s. This problem does not occur when using Chrome browser (v38). Note that my add-ons are up-to-date (I just have a handful of them). Running Win8.1 on Dell AIO 27, NVIDIA display. Expected results: Video play should be smooth and sound should be in sync.
Could you try: 1) in safe mode: https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode 2) with a clean profile: https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles Is it better? In addition, type about:support and paste the section "graphics" here.
(1) It worked somewhat better in safe mode - less choppy - but video started to lag sound after just a couple of minutes of video playing; more noticeable the longer I played the video. No add-on enabled, except of course OpenH264. No lag whatsoever on Chrome. (2) Also created and used a new profile; no positive impact there either. Here is a snapshot of the graphics parameters. Please advise on what I could try next. Adapter Description Intel(R) HD Graphics 4600 Adapter Description (GPU #2) NVIDIA GeForce GT 750M Adapter Drivers igdumdim64 igd10iumd64 igd10iumd64 igdumdim32 igd10iumd32 igd10iumd32 Adapter Drivers (GPU #2) nvd3dumx,nvwgf2umx,nvwgf2umx nvd3dum,nvwgf2um,nvwgf2um Adapter RAM Unknown Adapter RAM (GPU #2) 2048 Device ID 0x0412 Device ID (GPU #2) 0x0fe4 Direct2D Enabled true DirectWrite Enabled true (6.3.9600.17111) Driver Date 1-22-2014 Driver Date (GPU #2) 11-11-2013 Driver Version 10.18.10.3412 Driver Version (GPU #2) 126.96.36.19982 GPU #2 Active false GPU Accelerated Windows 1/1 Direct3D 11 (OMTC) Vendor ID 0x8086 Vendor ID (GPU #2) 0x10de WebGL Renderer Google Inc. -- ANGLE (Intel(R) HD Graphics 4600 Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote true AzureCanvasBackend direct2d AzureContentBackend direct2d AzureFallbackCanvasBackend cairo AzureSkiaAccelerated 0
User Agent Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:46.0) Gecko/20100101 Firefox/46.0 Build ID 20160104030217 Tested on Windows 8.1 x64 with the Nightly 46.0a1 build. I can't reproduce the problem. Please retest this issue with the latest version of Firefox (https://www.mozilla.org/en-US/firefox/new/). Thank you.
I reported this problem about 3 months ago. Problem vanished as of FFv36 I believe.