"media.hardware-video-decoding.force-enabled" doesn't exist anymore.

(In reply to Gerald Squelart [:gerald] (he/him) from comment #5)

"media.hardware-video-decoding.force-enabled" doesn't exist anymore.

Are you sure? I'm still having it in about:config and it's still visible in Searchfox ( https://searchfox.org/mozilla-central/search?q=media.hardware-video-decoding.force-enabled&path= )

If you look at the Searchfox results, it's only mentioned in a list of known static prefs, but there's is no code actually checking it! I'm guessing it's an oversight.

Compare with "media.hardware-video-decoding.enabled": https://searchfox.org/mozilla-central/search?q=media.hardware-video-decoding.enabled&case=false&regexp=false&path= , where you can see it's used in gfx/thebes/gfxPlatform.cpp.

I'll open a bug for the media team to remove the unused "media.hardware-video-decoding.force-enabled".

Oh, true. Thank you very much for detailed information!

See https://bugzilla.mozilla.org/show_bug.cgi?id=1594242#c1.

It looks like I was wrong about "media.hardware-video-decoding.enabled", it's used in code under a different name: https://searchfox.org/mozilla-central/rev/d061ba55ac76f41129618d638f4ef674303ec103/gfx/thebes/gfxPlatform.cpp#2447
Sorry for the confusion, Virtual_ManPL.

Andreas, I've been out of media playback for a while, so could you please find someone who may be better able to follow up?
I'm resetting the priority, so you can triage it appropriately again.

Ok, so coming in 3.5 years after the bulk of this was filed let's back up a bit. Virtual, do you still experience these problems?

In code it looks like we'll allow using hw decoding if media.hardware-video-decoding.force-enabled is true and media.hardware-video-decoding.failed is false. Note that media.hardware-video-decoding.failed gets set after a sanity test has run. The sanity test gets re-run after a change in graphics card or driver, or after a Firefox update. You could force it to be re-run by setting sanity-test.running to false and restarting I suppose.

It looks like media.hardware-video-decoding.force-enabled isn't designed to have an effect if the hardware-decoded video cannot be rendered, because that wouldn't be useful anyway. That seems reasonable to me. Does this match what you have experienced?

(In reply to Andreas Pehrson [:pehrsons] (On leave; back Aug 1st 2020) from comment #11)

Ok, so coming in 3.5 years after the bulk of this was filed let's back up a bit. Virtual, do you still experience these problems?

No, I can't reproduce it anymore. It was reproducible for me after landing bug #1242343. After landing additional fix in bug #1253395, I can't reproduce it anymore, as I have now hardware accelerated video decoding enabled. Maybe someone still can reproduce it.

(In reply to Andreas Pehrson [:pehrsons] (On leave; back Aug 1st 2020) from comment #11)

In code it looks like we'll allow using hw decoding if media.hardware-video-decoding.force-enabled is true and media.hardware-video-decoding.failed is false. Note that media.hardware-video-decoding.failed gets set after a sanity test has run. The sanity test gets re-run after a change in graphics card or driver, or after a Firefox update. You could force it to be re-run by setting sanity-test.running to false and restarting I suppose.

It looks like media.hardware-video-decoding.force-enabled isn't designed to have an effect if the hardware-decoded video cannot be rendered, because that wouldn't be useful anyway. That seems reasonable to me. Does this match what you have experienced?

Thank you very much for very detailed information! My point was that, when bug #1242343 landed, it forced disabled hardware accelerated video decoding. When I wanted to forced enabled it by using "media.hardware-video-decoding.force-enabled" preference and setting it to "true" in about:config/Advanced Preferences, it did nothing. In my opinion, it should omit any test, etc. and force enable what I wanted, same as it's with other preferences, like for example, it is with: remote, ipc, e10s, layers, direct2d, direct3d, webrender, etc.

Hey Virtual,
Can you still reproduce this or should we close it?

Yes. The issue still occurs. It was explained in detail in comment #12.

In the process of migrating remaining bugs to the new severity system, the severity for this bug cannot be automatically determined. Please retriage this bug using the new severity system.

Hello. Maybe this is wrong thread for such, but fix media.hardware-video-decoding.failed I have win 7 x64 and it was set to true value. I think, this is because I'm overclocking for several weeks and have videographics driver crashed several time, during Firefox open with twitch stream plays, after driver restart, I saw blank firefox window, had to close it and I think from this problem started

Just found the reason of why I'm always have huge CPU load while playing twitch = youtube vids, while my GPU video engine load is 0 always. Tried graphics driver reinstall / turn on off hardware accel in FF settings, nothing.