1982568 - HBO Max playback has audio but no video on Firefox 115 and 128 ESR

Status: RESOLVED WORKSFORME

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

Description

[Simona Badau, Desktop QA]

Attachment: Screen recording with the issue

Found in

• Firefox 128.14.0esr

Affected versions

• Firefox 128.14.0esr
• Firefox 115.27.0esr

Tested platforms

• Affected platforms: Windows 11, macOS 13, Ubuntu 25.04

Steps to reproduce

1. Navigate to https://play.hbomax.com and login.
2. Play any video.

Expected result

• Video playback should work normally with Widevine DRM.

Actual result

• Video does not display; only audio is heard. Please refer to the attached screen recording for more details (the recording includes audio).

Regression range

• Issue occurs on Firefox 115 and 128 ESR versions; other Firefox branches( ESR 140, Release, Beta and Nightly) play video correctly on HBO.

Additional notes

• I could also reproduce the issue with Firefox 115.26 ESR and 128.13 ESR.
• Widevine version: 4.10.2891.0

Comment 1

[Jim Mathies [:jimm]]

fail to play video in 128 - https://share.firefox.dev/4oyDtd7

audio continued to play, video was missing.

Comment 2

[Andrew Osmond [:aosmond] (he/him)]

In bug 1944386 comment 14 nearly 3 weeks ago, when we did an uplift to support the CDM interface v11, we did smoke testing on 115.26.0esr and 128.13.0esr which passed on HBO.

Comment 3

[Andrew Osmond [:aosmond] (he/him)]

I think the audio plays because it isn't encrypted. We don't do much in the GMP process, aside from some minimal session key setup which seemingly succeeded. It does not attempt to setup for video decoding.

Comment 4

[Andrew Osmond [:aosmond] (he/him)]

It fails to support Widevine:

LogMessages — (EME) MediaKeySystemConfiguration (label='') MediaKeySystemMediaCapability('video/mp4;codecs="avc1.42E01E"','HW_SECURE_DECODE','') unsupported; unsupported robustness string.
LogMessages — (EME) MediaKeySystemConfiguration (label='') rejected; no supported video capabilities.
LogMessages — (EME) MediaKeySystemConfiguration (label='') rejected; no supported video capabilities.
LogMessages — (EME) navigator.requestMediaKeySystemAccess promise rejected 0x80530009 'Key system configuration is not supported'

It then appears to try to fallback to playready, which I guess is enabled in 140ESR but not 115ESR and 128ESR.

Comment 5

[Andrew Osmond [:aosmond] (he/him)]

Oh wait that's just checking for HW decoding support, makes sense, then falls back to create the regular Widevine session....

Comment 6

[Alastor Wu [:alwu]]

This issue occurs when video suspension is triggered by the visibility logic marking the video element as invisible, either due to DOM detachment or being outside the viewport. As a result, playback continues with audio only because normal video decoding is never resumed. Disabling the pref media.suspend-background-video.enabled should work around the problem.

The detailed analysis available here: https://github.com/alastor0325/Firefox-profiler-assistant/blob/main/knowledge/raw/profiler/bug1982568_video_suspend.md

Comment 7

[Alastor Wu [:alwu]]

Does this issue also occur on the latest Nightly and ESR 140? If not, do we still need to pursue a fix for ESR 115 and 128?

Comment 8

[Brindusa Tot, DTE]

Alastor, this issue is reproducible only on ESR 115 and ESR 128. It is NOT reproducible on other Firefox branches - ESR 140, Release, Beta and latest Nightly.

Comment 9

[Brindusa Tot, DTE]

(In reply to Alastor Wu [:alwu] from comment #6)

This issue occurs when video suspension is triggered by the visibility logic marking the video element as invisible, either due to DOM detachment or being outside the viewport. As a result, playback continues with audio only because normal video decoding is never resumed. Disabling the pref media.suspend-background-video.enabled should work around the problem.

The detailed analysis available here: https://github.com/alastor0325/Firefox-profiler-assistant/blob/main/knowledge/raw/profiler/bug1982568_video_suspend.md

Tested on ESR 115 and ESR 128 with pref 'media.suspend-background-video.enabled' set to TRUE and FALSE and hbo videos do not work on either case.

Comment 10

[Alastor Wu [:alwu]]

If so, could you please capture a media profile with the pref media.suspend-background-video.enabled=false by following this instruction? Thanks.

Comment 11

[Andrew Osmond [:aosmond] (he/him)]

Could you also supply a working profile on nightly for comparison? It would be good to confirm what pathway we are using for EME.

Comment 12

[Brindusa Tot, DTE]

The bug is no longer reproducible today with pref media.suspend-background-video.enabled=true or false; the HBO videos now work on all Firefox versions - tested on Windows 7, macOS 10.12 and Ubuntu 22.04 with Firefox ESR 115.27 and ESR 115.26.0 and on Windows 11, macOS 12ARM and Ubuntu 22 with ESR 128.13 and ESR 128.14.

Also verified and HBO videos work on other Firefox branches: ESR 140, RC 142.0, Release 141.0.3 and latest Nightly.

Comment 13

[Alastor Wu [:alwu]]

Per comment 12, it seems likely that the issue was caused by their own incorrect CSS, which hid the video element and triggered video suspension.