[Bug 1654480]
I started digging into the SoundTouch library and confirmed my suspicion. https://hg.mozilla.org/mozilla- central/file/tip/media/libsoundtouch/src/TDStretch.cpp#l637 Author says it's implemented using "WSOLA-like method". Waveform- similarity-based synchronized overlap-add. Maybe based on this paper from 1993? https://www.semanticscholar.org/paper/An-overlap-add- technique-based-on-waveform-(WSOLA)-Verhelst- Roelands/d94abd77e52a56c425e4b86e6c7d692583ea406d Perhaps it doesn't scale well past 2x. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
>From the author: https://www.surina.net/article/time-and-pitch- scaling.html -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
Created attachment 9114055 2019-12-05_21-14-30 missing samples.png Top is 3x. Bottom is 1x. Estimate of the amount of audio data that is skipped before waveforms align. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
Thanks. The patch is a significant improvement! At 4x with 10ms window, it's easy to comprehend speech. There is some slightly noticeable choppiness in some videos. I'm not an audio expert, but I tried to do some analysis using Audacity + Gimp. I plotted both track as Mel Spectrograms, took a screenshot, aligned the two graphs in Gimp, set the layer mode to difference. There are some noticeable periodic artifacts. Perhaps related to the "sliding" part of the algorithm. I'll try 1ms later today. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
Created attachment 9114054 2019-12-05_21-09-44 3x identical to 1x.png In this screenshot, the first track is Chrome, 2nd track is Firefox at 3x, and 3rd track is Firefox at 1x. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
I used MOZ_DUMP_AUDIO=1 to capture samples from 1x vs 3x. The waveforms at 3x are identical to 1x for about 45ms. Then it skips and copies another 45ms. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480]
With the SoundTouch algorithm there isn't much improvement with a window size below 10ms. I found a quicker way to test various parameters using mpv, which uses same/similar algo. When I get some time I'll generate random samples with various parameters and do a blind perceptual test. mpv --af=scaletempo=stride=8:overlap=1:search=10 --speed=4 test.mp3 * Overlap in this case is a percentage rather than ms. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480] Re: HTML5 sound choppy when played at 4x
This bug should have been opened with Firefox instead. I found the ticket: https://bugzilla.mozilla.org/show_bug.cgi?id=1427267 ** Bug watch added: Mozilla Bugzilla #1427267 https://bugzilla.mozilla.org/show_bug.cgi?id=1427267 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
[Bug 1654480] [NEW] HTML5 sound choppy when played at 4x
Public bug reported: I use a bookmarklet to set the playback rate on the HTML5 player element to 4x (tested with YouTube). Chrome handles the audio flawlessly, but Firefox becomes choppy after 2x. Here's the bookmarklet. The following line may get mangled or removed... "javascript:%7Bvar%20v%3Ddocument.getElementsByTagName(%22video%22)%5B0%5D%3Bv.playbackRate%3D4%3B%7Dvoid(0)%3B" ProblemType: Bug DistroRelease: Ubuntu 16.04 Package: firefox 50.1.0+build2-0ubuntu0.16.04.1 ProcVersionSignature: Ubuntu 4.4.0-57.78-generic 4.4.35 Uname: Linux 4.4.0-57-generic x86_64 NonfreeKernelModules: nvidia_modeset nvidia AddonCompatCheckDisabled: False ApportVersion: 2.20.1-0ubuntu2.4 Architecture: amd64 BuildID: 20161209095719 Channel: Unavailable CurrentDesktop: GNOME Date: Thu Jan 5 20:28:52 2017 Extensions: extensions.sqlite corrupt or missing ForcedLayersAccel: False IfupdownConfig: # interfaces(5) file used by ifup(8) and ifdown(8) auto lo iface lo inet loopback IncompatibleExtensions: Unavailable (corrupt or non-existant compatibility.ini or extensions.sqlite) InstallationDate: Installed on 2016-12-21 (16 days ago) InstallationMedia: Ubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) IpRoute: default via 192.168.0.1 dev enp9s0 proto static metric 100 169.254.0.0/16 dev enp9s0 scope link metric 1000 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 linkdown 192.168.0.0/24 dev enp9s0 proto kernel scope link src 192.168.0.108 metric 100 Locales: extensions.sqlite corrupt or missing Plugins: Gnome Shell Integration - /usr/lib/mozilla/plugins/libgnome-shell-browser-plugin.so (gnome-shell) Shockwave Flash - /usr/lib/flashplugin-installer/libflashplayer.so PrefSources: prefs.js ProcEnviron: LANGUAGE=en_US PATH=(custom, no user) XDG_RUNTIME_DIR= LANG=en_US.UTF-8 SHELL=/bin/zsh Profiles: Profile0 (Default) - LastVersion=50.1.0/20161209095719 (In use) RelatedPackageVersions: gnome-shell 3.18.5-0ubuntu0.2 RunningIncompatibleAddons: False SourcePackage: firefox Themes: extensions.sqlite corrupt or missing UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/11/2016 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 1.40 dmi.board.asset.tag: Default string dmi.board.name: X99A GODLIKE GAMING (MS-7883) dmi.board.vendor: MSI dmi.board.version: 1.0 dmi.chassis.asset.tag: Default string dmi.chassis.type: 3 dmi.chassis.vendor: MSI dmi.chassis.version: 1.0 dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr1.40:bd04/11/2016:svnMSI:pnMS-7883:pvr1.0:rvnMSI:rnX99AGODLIKEGAMING(MS-7883):rvr1.0:cvnMSI:ct3:cvr1.0: dmi.product.name: MS-7883 dmi.product.version: 1.0 dmi.sys.vendor: MSI ** Affects: firefox (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug xenial -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1654480 Title: HTML5 sound choppy when played at 4x To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1654480/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
