Firefox Community Forum

(AI written summary of troubleshooting steps taken before making this support thread)

Firefox version: - 152.0.1 Release - 153.0 Nightly

OS: - Windows 11 build 26200

GPU: - NVIDIA GeForce RTX 4070 SUPER

Codec package: - Microsoft HEVC Video Extensions installed from Microsoft Store

Problem

Firefox does not expose HEVC playback support, causing Twitch to disable 1440p streams encoded with HEVC.

The same machine can play the same HEVC Twitch streams in Chrome immediately after installing HEVC Video Extensions.

Expected result

Firefox should report HEVC playback support and allow playback of HEVC streams, as Chrome does on the same system.

Actual result

Firefox reports HEVC as unsupported.

about:support:

codecSupportInfo: H264 SWDEC HWDEC VP9 SWDEC HWDEC VP8 SWDEC HWDEC AV1 SWDEC HWDEC HEVC NONE

Troubleshooting already performed

- Installed Microsoft HEVC Video Extensions - Rebooted Windows - Updated NVIDIA drivers - Verified hardware acceleration is enabled - Tested with a brand new Firefox profile - Tested with Firefox Nightly - Confirmed Chrome can play the same HEVC streams

Additional observations

Chrome: - Twitch 1440p becomes available immediately after installing HEVC Video Extensions - Twitch Stats for Nerds reports:

 hev1.1.6.L150.90.0.0.0.0.0

Firefox: - Twitch reports that the browser does not support the required resolution - 1440p remains greyed out - about:support continues to report HEVC NONE

Reproducible tests

Firefox console:

MediaSource.isTypeSupported('video/mp4; codecs="hev1.1.6.L150.90"')

Result: false

MediaSource.isTypeSupported('video/mp4; codecs="hvc1.1.6.L150.90"')

Result: false

navigator.mediaCapabilities.decodingInfo({

 type: "media-source",
 video: {
   contentType: 'video/mp4; codecs="hev1.1.6.L150.90"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: false,
 smooth: false,
 powerEfficient: false

}

For comparison:

MediaSource.isTypeSupported('video/mp4; codecs="av01.0.08M.08"')

Result: true

navigator.mediaCapabilities.decodingInfo({

 type: "file",
 video: {
   contentType: 'video/mp4; codecs="av01.0.08M.08"',
   width: 2560,
   height: 1440,
   bitrate: 8000000,
   framerate: 60
 }

})

Result: {

 supported: true,
 smooth: true,
 powerEfficient: true

}

Additional note

Setting:

dom.media.webcodecs.h265.enabled = true

causes HTML5 codec test (https://html5test.co/) to report H.265 support, but does not change:

- about:support - MediaSource.isTypeSupported() - MediaCapabilities.decodingInfo() - Twitch HEVC playback availability

Question

Is this a known issue with HEVC Media Source Extensions support on Windows 11 build 26200, or is there another requirement for Firefox to expose HEVC playback capability through MediaSource and MediaCapabilities when the Windows HEVC codec is installed and functioning in Chromium-based browsers?

My Youtube video stutters every 6-10 seconds. When I turn off my HW acc off, this issue happened. Turning the HW acc on solve it, but the thing is if I have my HW acc on another problem came up, which is my Firefox will starts to blink. Anyone has a solution for this?

After a Windows 11 update my Firefox browser no longer has any audio. The sound is turned all the way up in the Sound Mixer and I have no Bluetooth devices connected. After it initially happened I connected my Bluetooth earbuds and it worked for a few minutes before it too lost audio.

I have audio on all my other applications.

'how to cast videos from my phone to my TV if I got android phone, and I have i basic Sylvania TV without wifi or Bluetooth connection, hmi and a softwaode with fire fox app.

Hello All,

I have a somewhat confusing issue that I've only found two posts on Reddit mentioning previously, but there were no responses.

A short summary: On Discord's website, in an audio call, audio will progressively move from stereo/both ears to mono/only the right ear after anywhere from five to sixty seconds. This only occurs on Firefox, it does not occur on Chrome or Edge (with the same extensions, when applicable.) For the record - this also only occurs with the one headset. I've tried with a second headset and don't have the same issue, but I don't believe the Headset is solely to blame since the issue only happens on Firefox.

I have also tested on Firefox Nightly as a fresh install - no extensions, no settings changed, just install and login to Discord.

Specs:

ASUS TUF Dash F15 FX517ZR HP USB-C G5 Essential Dock (Monitors are connected through it) Windows 11 (August update/build 26200.9168) Razer Blackshark V2 Pro RZ04-0453 headset (Connects via USB-A Dongle plugged in to the laptop) Firefox (x64) (154.0.1)

Troubleshooting steps I've taken:

Removing the Audio driver for my computer and re-installing it. Removing/re-installing the drivers for the Headset. Verified all audio related drivers for my device are up to date. Verified the BIOS is up to date (it's solved unusual problems before) Toggling the "media.latency_preference" toggle in about:config (recommendation from a friend) Disabling all extensions on Discord. Disabling Firefox's strict mode on Discord. Verifying all audio related drivers for my device are up to date. Tested on a Firefox Nightly install (the first time it's been installed on my device). A separate browser (Chrome/Edge - the issue is not present) A separate headset (Issue is not present) Downloading Razer Synapse and disabling any "extra" features, and testing with various options on/off. Disabling any and all other Audio devices (speakers and microphones) while using the headset. Charging the Headset to full.

Things I haven't tested, but thought of:

Resetting Firefox in any capacity - I can, but hopefully testing with Nightly is sufficient. A different computer entirely - on my list, when I can next. A new User profile. Testing with no headset at all, and just utilizing the built-in speakers/microphone for the laptop.

Oddities:

Changing audio settings in Windows will "fix" the issue momentarily - for instance the "Spatial sound" option. Changing from one setting to "Off" (or vice versa) fixes the issue for the same ~5-60 seconds until it slowly goes back to the right ear. These options are present for every device, even ones not experiencing this issue.

It's very odd to me because on one hand it may be the headset, but then the issue is only present in Firefox.

Any help or things to test would be greatly appreciated!

Thank you.

I can't seem to get microphone and video to work I've checked the permissions and still it's not working. I need to sign a docusign with a notary and time is of the essence . I am about to throw the phone at the wall. please help

It was working fine until the day before yesterday. The volume of the speaker got low before it stopped working. The PodCast and Vimeo are working fine. So it is not the problem of my computer speaker.

Hello Firefox Support Team/Forum

I am writing to request guidance on a hardware video acceleration issue that I have been unable to resolve despite extensive troubleshooting. Firefox appears to be blocking VA-API hardware decoding on my system even though the VA-API stack is confirmed working at the system level. — SYSTEM SPECIFICATIONS — OS: Arch Linux (rolling), kernel 7.0.13-arch1-1 Desktop: Hyprland 0.55.4 (Wayland, DRM backend) CPU: AMD A9-9425 (2 cores, 3.1GHz, Excavator architecture) RAM: 8GB Firefox: installed via pacman (native, not Flatpak) Mesa: 26.1.3-arch1.2 GPU setup (dual): • card0 / renderD128: AMD Stoney R5 Graphics (iGPU) — VA-API confirmed working here • card1 / renderD129: AMD Hainan R5 M435 (dGPU) — used by Hyprland for display output — CONFIRMED WORKING AT SYSTEM LEVEL — Running ‘vainfo’ on the integrated GPU (renderD128) confirms the following profiles are available: VAProfileH264ConstrainedBaseline, VAProfileH264Main, VAProfileH264High (VLD + EncSlice) VAProfileHEVCMain, VAProfileHEVCMain10 (VLD) VAProfileMPEG2Simple, VAProfileMPEG2Main, VAProfileVC1 (VLD) VAProfileJPEGBaseline (VLD) MPV with ‘–hwdec=vaapi-copy’ successfully hardware-decodes H264 locally, confirmed by ‘nv12’ pixel format output and reduced CPU usage. radeontop monitoring card0 (stoney, bus 00) during Firefox video playback shows: • Graphics pipe: ~53% (compositing activity) • UVD row: absent / 0% (no hardware video decode activity) • Memory clock: near 0.00G This confirms Firefox is NOT using the hardware decoder despite VA-API being functional. — FIREFOX DECISION LOG (from about:support) — HARDWARE_VIDEO_DECODING: default available / user force_enabled H264_HW_DECODE: default available (no blocklist) HEVC_HW_DECODE: default available VP8_HW_DECODE: env blocklisted — FEATURE_FAILURE_VIDEO_DECODING_MISSING VP9_HW_DECODE: env blocklisted — FEATURE_FAILURE_VIDEO_DECODING_MISSING AV1_HW_DECODE: env blocklisted — FEATURE_FAILURE_VIDEO_DECODING_MISSING DMABUF_SURFACE_EXPORT: env blocked — FEATURE_FAILURE_BROKEN_DRIVER WEBRENDER_COMPOSITOR: env blocklisted — FEATURE_FAILURE_WEBRENDER_COMPOSITOR_DISABLED Note: VP8/VP9/AV1 being missing is expected and correct for this GPU generation. The concern is that H264, which IS in the vainfo profile list and shows as ‘available’ in the decision log, is still not being routed to the hardware decoder in practice. — ENVIRONMENT VARIABLES IN USE — MOZ_ENABLE_WAYLAND=1 LIBVA_DRIVER_NAME=radeonsi LIBVA_DRM_DEVICE=/dev/dri/renderD128 MOZ_DISABLE_RDD_SANDBOX=1 — about:config SETTINGS CURRENTLY SET — media.ffmpeg.vaapi.enabled = true media.hardware-video-decoding.force-enabled = true media.hardware-video-decoding-vulkan.enabled = false media.rdd-process.enabled = true — WHAT WAS TRIED — 1. Installed full Mesa stack: mesa, libva-mesa-driver, libva-utils, ffmpeg, vulkan-radeon (64-bit and 32-bit variants via multilib). 2. Set LIBVA_DRM_DEVICE=/dev/dri/renderD128 to hardcode VA-API to the stoney iGPU and prevent it from accidentally targeting the hainan dGPU (which fails Firefox’s internal VA-API test with FEATURE_FAILURE_VIDEO_DECODING_TEST_FAILED). 3. Enabled media.ffmpeg.vaapi.enabled and media.hardware-video-decoding.force-enabled in about:config. 4. Disabled MOZ_DISABLE_RDD_SANDBOX via both ~/.bash_profile and hl.env() in the Hyprland Lua config to allow Firefox’s RDD process to access /dev/dri/renderD128. 5. Installed enhancedH264ify extension with VP9 and AV1 blocking enabled. YouTube confirms H264 (avc1.64002a) is being served. Despite this, over 1100 frames out of ~4200 are dropped during 1080p60 playback. 6. Verified with radeontop -b 0 (stoney, bus 00) during active 1080p H264 playback: the UVD block shows no activity whatsoever, confirming the CPU is doing all decoding. 7. Tested with and without gfx.webrender.all = true. Enabling it caused severe visual corruption (texture artifacts, split UI elements), so it was reset to default. 8. Did NOT disable media.rdd-process.enabled (correctly kept at true, as RDD is the process Firefox uses for VA-API decoding). 9. Confirmed Firefox is installed via pacman (not Flatpak), so there is no Flatpak sandbox layer involved. — THE CORE QUESTION — Given that: • vainfo confirms H264 hardware decode is available on renderD128 • H264_HW_DECODE shows as ‘default available’ in Firefox’s own decision log with no blocklist entry • media.hardware-video-decoding.force-enabled is set to true • MOZ_DISABLE_RDD_SANDBOX=1 is set • LIBVA_DRM_DEVICE explicitly points to the correct render node • MPV successfully uses vaapi on the same system …why is Firefox’s RDD process still not routing H264 decoding through VA-API, and what additional steps or logs would help identify the specific internal failure point?

Any guidance on enabling verbose VA-API logging within Firefox’s RDD process, or any known issues with AMD Stoney + Hainan dual-GPU setups on Wayland that might explain the DMABUF_SURFACE_EXPORT FEATURE_FAILURE_BROKEN_DRIVER blocklist, would be greatly appreciated.

Thank you.

After a Windows 11 update, every time I play some video/sound and stop the playback, my whole computer audio doesn't work anymore. When I reset my computer, the audio comes back again. I tried using other browsers (Edge, Chrome, etc.) and other programs/applications, but this only happens in Firefox.

Any ideas on what can I do to solve this issue?

Basic information:

Firefox version: 133.0.3 (64-bits) Operation System: Microsoft Windows 11 Home Single Language OS Version: 10.0.26100 Compilation 26100 Computer Brand: Alienware m16 R2 Sound drivers: Realtek Semiconductor Corp. version 6.0.9738.1

No audio on Firefox. Google Chrome has sound. Settings at normal audio volumes. Tried computer shut off and re-boot. Tried reload of Firebox.but that didn't help. Had scam attempt just before no audio issue...not sure if that problem.

Hello,

I am a new firefox user and would like to use it 100%, but have been running into a few bugs. This one I have been unable to find this issue myself, so thought I would ask here. I use Qobuz to stream hi-res music up to 24bit/ 192kHz. Some albums do not have sound at that resolution. The file will load and timer shows the song is playing, but there is no audio. I can change the setting to stream at 16bit/44.1kHz and then I get audio. Again, this does not occur with all albums, some will stream at hi-res and some will not. An interesting note: the same file with no audio at hi-res on firefox will have audio at same resolution setting on chrome. The only thing I can think of is chrome is reducing resolution in the background, or maybe a DRM issue? I do have "Play DRM-controlled content" checked in firefox settings.

p.s. I am aware that streaming music through a browser is not necessarily the best way to listen to hi-res music, and my ears may, or may not hear the difference between the 16bit and 24bit. However, the issue is the functionality, or lack of.

Thank you in advance for any insight.

No matter what settings I change, I still can't get audio to play from Firefox. I can use other browsers and get audio so I know it’s not my computer. I’ve even tried to uninstall firefox and install the newest version with no luck on getting my audio issue resolved. If anyone has any advice for me, it’d be greatly appreciated