User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.105 Safari/537.36

Steps to reproduce:

I try to play a base64-inlined video through HTMLVideoElement as shown in https://jsfiddle.net/zeno/y120cwsb/.

The issue is intermittent, I do not reproduce every time making hard to determine any scenario. I am using Firefox 79 on macOS Catalina 10.15.6 (default settings).

Actual results:

A MediaError is triggered by the HTMLVideoElement:

Code: 3
Message: NS_ERROR_DOM_MEDIA_DECODE_ERR (0x806e0004) - void mozilla::AppleVTDecoder::OnDecodeError(OSStatus): OnDecodeError:ffffcd9a

A warning is displayed in the Console:

"This error message will be blank when privacy.resistFingerprinting = true. If it is really necessary, please add it to the whitelist in MediaError::GetMessage: NS_ERROR_DOM_MEDIA_DECODE_ERR (0x806e0004) - void mozilla::AppleVTDecoder::OnDecodeError(OSStatus): OnDecodeError:ffffcd9a"

Expected results:

The media should play without triggering warnings and MediaError.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

So far none of us have been able to successfully reproduce this. If you discover anything that makes it more consistent, that would definitely help.

1. Does this problem still occur with https://nightly.mozilla.org?
2. Could you try to find a regression range?
   mozregression --good 75 --bad 79 -a https://jsfiddle.net/zeno/y120cwsb/
   Tutorial for macOS:
   (Stephen A Pohl [:spohl] from bug 1659370 comment 3)

   could you run mozregression to see when this might have started happening?

   If you have never run mozregression before, simply run these three commands in a Terminal window:

   sudo easy_install pip
   sudo pip install -U mozregression --ignore-installed
   mozregression --good 2017-01-01
   

   A number of Firefox versions will open in succession to narrow down when this started occurring. Simply type "good" or "bad" in Terminal based on whether or not a build reproduces the bug. Once finished, please post the output from the last run. It should give a last good and first bad revision as well as a link to look at the changesets in that range. Thank you!

   [1] https://mozilla.github.io/mozregression/

Could this be related to 1652689? I can reproduce this on my browser (Firefox 80 on MacOS Catalina 10.15.6), which is affected by 1652689. Some tabs work, some tabs don't. Also, video's small resolution looks in line with what was observed in the other issue.

Can you sometimes reproduce this with other small non-base64 mp4 videos: for example, https://file-examples-com.github.io/uploads/2017/04/file_example_MP4_480_1_5MG.mp4, or http://mirrors.standaloneinstaller.com/video-sample/metaxas-keller-Bell.mp4, or other videos <= 240p?

Hello,
Following this issue for some time, I noticed I almost never reproduce it when I open the link the first time, but more often when I keep the tab open, let my computer in sleep mode, then come back and try again the next day. Hope that helps.
Reproduced the last time on Firefox 81.0.2 (64 bits), MacOS Catalina 10.15.7

Hello,
I just had the issue on Firefox 86.0 (64 bits) on MacOS Catalina 10.15.7. I opened private navigation window and had the issue too.
When I close all Firefox window and try again the issue wasn't reproductible anymore.

I'm also seeing this since a while, currently in FF 86.0.1, macOS Catalina 10.15.7 (19H2).

Sometimes when I force-refresh the video finally works, but sometimes it's also very persistent in not-working. :-(

If somebody could guide me how to collect more info, or drill down, I would appreciate it.

Same issues here. I can reproduce this and the two links by naktinis.
It works when I start firefox in troubleshoot mode. And then if I restart in normal mode, everything works fine magically. But it only lasts for a few hours. It will break again next day.

Currently using firefox 89.0.2 and macOS Catalina 10.15.7

I have the exact same issue and this is super frustrating. I also have firefox and a 2012 MacOS Catalina 10.15.7.
I am trying to take an online class for american sign language. the videos are a critical component.
how can this be repaired???
the online platform requires chrome or firefox, not safari.
i dislike chrome.

what to do???
2clars@gmail.com
thank you
URGENT
(P.S. i am just some random girl and have no idea about tech stuff)/

Redirect a needinfo that is pending on an inactive user to the triage owner.
:jimm, since the bug has recent activity, could you have a look please?

For more information, please visit auto_nag documentation.

Triage notes - intermittent issue, request to QA to try and reproduce, also would appreciate about:support text from reporters.

Redirect a needinfo that is pending on an inactive user to the triage owner.
:jimm, since the bug has recent activity, could you please find another way to get the information or close the bug as INCOMPLETE if it is not actionable?

For more information, please visit auto_nag documentation.

Changing qe-verify? to qe-verify+.

Redirect a needinfo that is pending on an inactive user to the triage owner.
:jimm, since the bug has recent activity, could you please find another way to get the information or close the bug as INCOMPLETE if it is not actionable?

For more information, please visit auto_nag documentation.