HD Youtube videos stutter on only the current Firefox (in my case 78 esr)
Only one Browser has problems with HD videos (1080p + above) on youtube: Firefox in the most current version.
I have tested so far only the one current latest version of the ESR branch (78.3.x). But as visible from thousands of articles to this very particular problem (when i search the community help database for "Youtube videos stutter" i get multiple thousands of entries - i read only a handful of them to realize that they are all "closed" and not a single one "solved"), this problem persists since multiple years now.
I have a very old PC by my side with a very old Firefox (benchmark wise slower than my current PC by a factor of at least 3) ESR 52.9, which is able to play the same videos in the same HD resolution without the slightest stutter.
The drivers on that old system are - naturally - outdated by half a decade. THAT OLD OUTDATED system with THAT OLD OUTDATED Firefox is well able to play even multiple HD videos side by side. With-OUT any stutter.
Thus, you can easily deduce by logical reasoning that nighter any outdating of drivers whatsoever nor any outdating of anything else on the system, be it hardware wise or software wise, CAN AT ALL be the culprit of that stuttering.
While the former holds true, what you actually find in the communities help are completely useless and irrational tips of "upgrading the browser to the last version", "upgrading drivers" or "reinstalling any software" or the like.
Let me be clear: Nothing of the latter will ever help in overcoming the stuttering of current firefoxes at all. The only one measure that will help here is to revise the code that is underlying the video pipe.
Since the stuttering regularly only begins after about one to two minutes into the videos, it is strongly suggestive that something in the memory management - probably in the way resources becoming freed after use - is accumulating over time until the stuttering begins. Badly managed garbage collection, perhaps?
All Replies (4)
You can right-click the video and use the "Stats for nerds" command on Google's custom context menu to compare the streams that the two browsers are playing and see whether there are any codec or other differences.
I suspect something must be different, for example, Firefox 52 might not be playing videos in "vp9" encoding, which can be very processor intensive in Firefox.
jscher2000 said
You can right-click the video and use the "Stats for nerds" command on Google's custom context menu to compare the streams that the two browsers are playing and see whether there are any codec or other differences.
Left of "versus": Firefox 52 - smooth / right of "versus": Firefox 78esr stuttering...
Video ID: identical sCPN: different (naturally) Viewport: 1263x710 versus 1280x720 - negligible Frames: 0 dropped of 50531 versus 1 dropped of 34312 (at negligibly different points in the video) Current / Optimal Res: identical (1920x1080@60 / 1920x1080@60) Volume / Normalized: identical Codecs: identical (avc1.64002a (299) / opus (251)) Connection Speed: 344'660 kbps versus 137'440 kbps (negligibly different because of being at least 1 decade more than necessary, adopting while playing) Network Activity: Nearly identical (a peak every few seconds) Buffer Health: orange/yellow sawtooth versus yellow/cyan sawtooth
Thus, it looks as if the "buffer health" is the only one significantly shining difference between the two. I know that the color here is significant, because the sawtooth on the side of the Firefox 78 had an orange/yellow color at the very beginning, too. Only after a few seconds, that sawtooth vanished to the roof of the buffer health display and got replaced by the yellow/cyan one.
Of course, i have no clue what's the meaning of those colors. Ball passed...
Update to research state:
I recently stumbled over timing issues with video streams in Blender. Poking around the internet for possible explanations, i stumbled over the terms "DTS" (decoding timestamp?), "PTS" (packet timestamp?) and "RTS" (recording timestamp?) relating to H.264 video streams.
I'm not sure about the meaning of the different timestamps YET, since i currently just poke into the matter the first time.
At that point the link to firefox playback stutter fired in my synapses.
Well: That stutter problem is STILL UNRESOLVED AND UNADDRESSED by the firefox developers - multiple years (!) after its introduction. It was introduced with the architectural break with version 62, if i'm not mistaken.
COULD it be that the programmers of that new architecture redesigned video playback, too, and by doing that changed to some library/code that does not take into account the possible unordered decoding sequence (since the decoding runs asynchronously decoupled from other stages of the pipeline) in relation to the necessary display sequence?!
It would make perfectly sense, since the stuttering gets THE BIGGER THE BETTER the system is on which firefox runs.
...To be sure this problem gets some attention, i will post a new question with a better fitting title for that matter...
Modified by White-Gandalf
Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.
- switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
- do NOT click the "Refresh Firefox" button on the Safe Mode start window
- https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-using-safe-mode
- https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems
You can create a new profile as a quick test to see if your current profile is causing problems.
See "Creating a profile":
If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.