1839107 - HEVC 10-bit HDR video is not playable

Status: UNCONFIRMED

(Core :: Audio/Video, defect)

Description

[iofelben]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:109.0) Gecko/20100101 Firefox/114.0

Steps to reproduce:

1. Open https://github.com/dtinth/superwhite
2. Notice that superwhite.mp4 is not playable in Firefox

Actual results:

I'm seeing this in the console:

Media resource https://user-images.githubusercontent.com/193136/246622910-311aac17-ff89-4700-a080-98dbe4424cbd.mp4 could not be decoded, error: Error Code: NS_ERROR_DOM_MEDIA_DEMUXER_ERR (0x806e000c)
Details: virtual RefPtr<MP4Demuxer::InitPromise> mozilla::MP4Demuxer::Init(): No MP4 audio () or video () tracks superwhite

Expected results:

This video works in safari. It should be super bright on an M1 Macbook pro

Comment 1

[BugBot [:suhaib / :marco]]

The Bugbug bot thinks this bug should belong to the 'Core::Audio/Video' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[BugBot [:suhaib / :marco]]

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

For more information, please visit BugBot documentation.

Comment 3

[Jim Mathies [:jimm]]

Fails on Windows as well. Clearly there's an issue with the container data format, likely related to the 10-bit content. We'll need to do some debugging to understand the specifics.

Comment 4

[Jim Mathies [:jimm]]

According to low level logging, this file uses HEVC (H265), which we currently do not support.

Comment 24

[mirh]

As mentioned in bug 1889731, it is actually supported (with some tinkering, at least on windows and linux)
But yeah, Main10 seems broken.

Comment 25

[Alastor Wu [:alwu]]

This 10bit HEVC video is actually playable since landing bug 1866265. However, it's still not rendered properly, which might be caused by HDR.

Comment 26

[Jim Mathies [:jimm]]

Hey Bob, can you ask the color team to triage this? My guess is this depends on overall HDR support (ignoring the 10-bit format) and would be dependent on platform support for HDR (like we have on mac currently). It also is dependent on HEVC support, which the media team is working on.

Comment 27

[Sky Schubert [:skyschub][Vacation, back 2026-08-24]]

Jeff removed the WebCompat blocking dependency 5 days ago, but the webcompat:platform-bug label is still here - so I'm removing that. We technically don't know about any real-world site breakage for this - except for the URL in comment 0, but we'd classify this as a "testcase", not a real site.