In bug 1233970 comment 71, Eric reports that Flash and VLC can play 1080p H.264 video "smooth as silk" on his Windows XP machine, but VP9 (when watching YouTube in Firefox 43+) is very choppy: "couple seconds play then freeze, repeat, but drop down to 360/480 and fine. … HD locks up system every couple moments on vimeo/dailymotion and other sites video playback is really choppy."

Eric, can you please copy/paste your Firefox Troubleshooting Information from about:support in this bug? That will help us debug this performance problem. Here are instructions: https://support.mozilla.org/en-US/kb/use-troubleshooting-information-page-fix-firefox

ok For record I do not have hardware acceleration anymore in h.264/flash content. When I upgraded to 43.0.4 I noticed html5 would not load at all on youtube and I had to reinstall flash. I noticed hd content in flash was choppy. Chris gave me a workaround in about:config to force html5 player to load, and it did but it too was choppy, the browser would play a couple seconds and freeze, which would lock everything up, I say that because moving mouse to stop the playback or close tab the mouse cursor froze on screen until the video would play a couple more seconds. I also went to vimeo/twitch/dailymotion and flashplayer autoload but the hd content struggled to play it did very similar to youtube freezing on html5. The the video would play a couple moments then choke/freeze/stutter. I saw that in the troubleshooting information that now it was reporting that h.264 hardware decoding was now showing not supported. 'Failed to create h.264 decoder'. I googled about loss of h.264 hardware acceleration since flash and html5 both couldn't play hd content. But my VLC player is set to hardware acceleration and plays 1080p h.264 encoded mk4/mp4 smooth as silk. You can even on this old XP box grab the vlc player window and drag it all over screen violently and it doesn't cause a stutter. The website I noticed a couple months ago mentioning losing hardware acceleration on h264 content was this which also links to a bug report on this site: http://www.sevenforums.com/browsers-mail/382635-firefox-drives-you-nuts-because-h264-decoding-poor-read-here.html Now I never had a problem with any video content, youtube/vimeo/dailymotion/twitch as this old xp box is primarily a hard drive packed backup server mainly. But often when I'm gaming on main pc I'll have a hd twitch stream on the xp box as I occasionally play multiplayer with a couple streamers. Or I may click a youtube link sent in facebook/email, without having to interrupt game on main pc. Everything both vp9 and flash played hd content ok no stutter even on this older system, up to 1080p, I never tried the 60fps or higher resolution as that's not expected on this pc. My nexus 7 tablet and main pc plays those just fine. My internet is 50 megabit vdsl2. Due to a little security until I can replace the motherboard/cpu/ram and get a small ssd for this XP box I've procrastinated upgrading to linux or win7 as other than when I'm gaming it's not used online and only for internal drive shares on lan. My video card in this box is an older evga geforce 9800 gtx+ the "overclocked" plus version. According to specs it supports. PureVideo HD: VP2, Core: G92, VDPAU feature set: A, further looking up "feature set A" I get info: Supports complete acceleration for H.264 and partial acceleration for MPEG-1, MPEG-2, VC-1/WMV9. Video on streaming sites was smooth and no performance issues then after the 43.0.2 all videos on youtube only played at 360p with no option for higher quality, clicking the 'quality missing' sent to a test site stating there was no support and listed supported browsers which Firefox was listed and I filed initial bug. 43.0.3 seemed to fix the issue with youtube and videos were fine there, although I admit I didn't do any full testing as I was unaware of other problems or if they existed. Then upgrading to 43.0.4 youtube would not load the html5 player at all, and it was sluggish, I was given the manual option to toggle in about:config to force html5 player and that brought the html5 player back to youtube but hd content in the player was not smooth anymore, sluggish, freezing up, as mentioned prior. Hopefully that explains most what I've experienced, I didn't do any extensive tests in between each version, because honestly as I've said in previous report, it's not a huge issue it is after all just XP and ill be getting rid of it soon when I swap out the motherboard/cpu and such. I also tested on website html5test.com and here's copy of the test: http://html5te.st/646bd32c3ae74530 you'll see on right h.264 and mpeg-4 with red X's. I will add a new reply with a copy and paste of my Troubleshooting information per Chris' instructions.

Application Basics ------------------ Name: Firefox Version: 43.0.4 Build ID: 20160105164030 Update Channel: release User Agent: Mozilla/5.0 (Windows NT 5.1; rv:43.0) Gecko/20100101 Firefox/43.0 Multiprocess Windows: 0/2 (default: false) Safe Mode: false Crash Reports for the Last 3 Days --------------------------------- All Crash Reports Extensions ---------- Name: Adblock Plus Version: 2.7 Enabled: true ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d} Name: FireFTP Version: 2.0.26 Enabled: true ID: {a7c6cf7f-112c-4500-a7ea-39801a327e5f} Name: NoScript Version: 2.9.0.2 Enabled: true ID: {73a6fe31-595d-460b-a920-fcc0f8843232} Name: Microsoft .NET Framework Assistant Version: 1.0 Enabled: false ID: {20a82645-c095-46ed-80e3-08825760534b} Graphics -------- Adapter Description: NVIDIA GeForce 9800 GTX+ Adapter Drivers: nv4_disp Adapter RAM: Unknown Asynchronous Pan/Zoom: none Device ID: 0x0613 DirectWrite Enabled: false (0.0.0.0) Driver Date: 3-14-2013 Driver Version: 6.14.13.1422 GPU #2 Active: false GPU Accelerated Windows: 2/2 Direct3D 9 (OMTC) Subsys ID: 0592196e Supports Hardware H264 Decoding: No; Failed to create H264 decoder Vendor ID: 0x10de WebGL Renderer: Google Inc. -- ANGLE (NVIDIA GeForce 9800 GTX+ Direct3D9 vs_3_0 ps_3_0) windowLayerManagerRemote: true AzureCanvasBackend: skia AzureContentBackend: cairo AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0 Important Modified Preferences ------------------------------ accessibility.typeaheadfind.flashBar: 0 browser.cache.disk.capacity: 153600 browser.cache.disk.filesystem_reported: 1 browser.cache.disk.hashstats_reported: 1 browser.cache.disk.smart_size_cached_value: 358400 browser.cache.disk.smart_size.enabled: false browser.cache.disk.smart_size.first_run: false browser.cache.disk.smart_size.use_old_max: false browser.cache.frecency_experiment: 1 browser.download.folderList: 0 browser.download.importedFromSqlite: true browser.download.useDownloadDir: false browser.places.smartBookmarksVersion: 7 browser.search.suggest.enabled: false browser.search.update: false browser.sessionstore.upgradeBackup.latestBuildID: 20160105164030 browser.startup.homepage_override.buildID: 20160105164030 browser.startup.homepage_override.mstone: 43.0.4 dom.apps.reset-permissions: true dom.mozApps.used: true dom.w3c_touch_events.expose: false extensions.lastAppVersion: 43.0.4 font.internaluseonly.changed: true gfx.crash-guard.d3d11layers.appVersion: 43.0.4 gfx.crash-guard.d3d11layers.deviceID: 0x0613 gfx.crash-guard.d3d11layers.driverVersion: 6.14.13.1422 gfx.crash-guard.d3d11layers.feature-d2d: true gfx.crash-guard.d3d11layers.feature-d3d11: true gfx.crash-guard.glcontext.gfx.driver-init.direct3d11-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle: true gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-d3d11: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-force-warp: false gfx.crash-guard.glcontext.gfx.driver-init.webgl-angle-try-d3d11: true gfx.crash-guard.status.d3d11layers: 2 gfx.crash-guard.status.glcontext: 2 gfx.driver-init.appVersion: 42.0 gfx.driver-init.deviceID: 0x0613 gfx.driver-init.driverVersion: 6.14.13.1422 gfx.driver-init.feature-d2d: true gfx.driver-init.feature-d3d11: true gfx.driver-init.status: 2 media.gmp-gmpopenh264.abi: x86-msvc media.gmp-gmpopenh264.lastUpdate: 1451513453 media.gmp-gmpopenh264.version: 1.5.3 media.gmp-manager.buildID: 20160105164030 media.gmp-manager.lastCheck: 1452219713 media.hardware-video-decoding.failed: false media.youtube-ua.override: false network.cookie.prefsMigrated: true network.http.speculative-parallel-limit: 0 network.predictor.cleaned-up: true places.database.lastMaintenance: 1451867493 places.history.expiration.transient_current_max_pages: 53666 plugin.disable_full_page_plugin_for_types: application/pdf plugin.importedState: true plugin.state.npdrmv: 0 plugin.state.npdsplay: 0 plugin.state.npwmsdrm: 0 plugin.state.npwpf: 0 privacy.donottrackheader.enabled: true privacy.sanitize.migrateFx3Prefs: true security.disable_button.openCertManager: false security.disable_button.openDeviceManager: false storage.vacuum.last.index: 1 storage.vacuum.last.places.sqlite: 1450484264 Important Locked Preferences ---------------------------- JavaScript ---------- Incremental GC: true Accessibility ------------- Activated: false Prevent Accessibility: 0 Library Versions ---------------- NSPR Expected minimum version: 4.10.10 Version in use: 4.10.10 NSS Expected minimum version: 3.20.2 Basic ECC Version in use: 3.20.2 Basic ECC NSSSMIME Expected minimum version: 3.20.2 Basic ECC Version in use: 3.20.2 Basic ECC NSSSSL Expected minimum version: 3.20.2 Basic ECC Version in use: 3.20.2 Basic ECC NSSUTIL Expected minimum version: 3.20.2 Version in use: 3.20.2 Experimental Features ---------------------

Eric, does YouTube give you Flash if you set the about:config pref "media.webm.enabled" to false?

You can also test whether this "YouTube Flash Video Player" add-on re-enables Flash YouTube for you. It successfully forces Flash YouTube on OS X for me. https://addons.mozilla.org/en-US/firefox/addon/youtube-flash-video-player/

Unfortunately, dropping Flash support is a YouTube decision. We can't support hardware decoding of H.264 on XP. We will be shipping some VP9 optimizations in Firefox 46 that might help. Also, we're working with YouTube to improve dropped frame handling.

h.264 acceleration worked perfectly before upgrading to 43.0.2! why the heck remove it without telling anyone? I get h.264 acceleration testing with Chrome. Or using oldversions and grabbing the version of firefox prior to 43.0.2 h.264 acceleration works perfectly. AND HTML5 VP9 was SMOOTH even at 1080p But I can't even play 480p VP9 videos Dropped Frames: 1411/1922 at 480p when before I played 1080p smooth and streamed live HD twitch streams. But I don't understand why arbitrarily REMOVE a feature that worked, h.264 hardware acceleration worked fine even in the past 20 versions so just randomly it was decided, "we need to remove acceleration for h.264 even though we force a cisco h.264 codec on all users"? Then leave hardware acceleration turned on. Or remove the cisco and let us use the h.264 nvidia codec or ffmpeg open source decoder. Or just put the acceleration back

(In reply to Eric from comment #7) > I get h.264 acceleration testing with Chrome. Or using oldversions and > grabbing the version of firefox prior to 43.0.2 h.264 acceleration works > perfectly. > > AND > > HTML5 VP9 was SMOOTH even at 1080p > > But I can't even play 480p VP9 videos Looking at your "Important Modified Preferences" data in comment 3, I don't see the "media.mediasource.webm.enabled" pref. That means it has the default value (false), so YouTube would have been sending you Flash video instead of HTML5 VP9 video in Firefox 42 and earlier. > when before I played 1080p smooth and streamed live HD twitch streams. Is Twitch video performance also worse after 43.0.2? > But I don't understand why arbitrarily REMOVE a feature that worked, h.264 > hardware acceleration worked fine even in the past 20 versions so just > randomly it was decided, "we need to remove acceleration for h.264 even > though we force a cisco h.264 codec on all users"? Then leave hardware > acceleration turned on. Or remove the cisco and let us use the h.264 nvidia > codec or ffmpeg open source decoder. You are right; if hardware acceleration is still available, then we would like to use unless there is a reason not to (such as GPU driver bugs). The Cisco OpenH264 codec is only used for WebRTC/Hello video, not video playback like YouTube.