1780905 - MP4 videos with moov box at the end of the file will display as corrupted if they do not load fully.

Status: RESOLVED DUPLICATE of bug 1781063

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

Description

[Zaggy1024]

Videos recorded by some real-time recording apps will write video data into one large MP4 mdat box before writing the metadata, so the moov box will not be written until the end of the file.

Chrome seems to buffer videos like this until it finds the moov box, but currently it appears that Firefox just considers the video corrupt because it can't find the box in the initial data sent to the parser.

I've tested this with a two videos other than the one linked below. One was generated by the Windows Game Bar like the example, and one was generated by Overwatch's in-game highlight recording system. Both exhibited the issue when played through an internet connection. Playing the affected videos locally avoids the issue.

Example: https://user-images.githubusercontent.com/15205088/175407710-39c2f6dc-2643-450f-b64b-ed6adad60feb.mp4

Comment 1

[Zaggy1024]

Based on this webcompat issue: https://github.com/webcompat/web-bugs/issues/106302

Comment 2

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=e15164d8b4c6de1bbb016649e32bd63797a7453a&tochange=56757e00ffb4fbea5c67b67d86d081949065dd6d

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The severity field is not set for this bug.
:jimm, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 4

[Karl Tomlinson (:karlt)]

Thank you for filing. The patch in bug 1781063 fixes this, so I'll dupe there.