Playback Troubleshooting: Difference between revisions

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Opera released an experimental Ogg Theora enabled build in 2007 as the very earliest attempt to support video in a browser ever, official HTML5 video support since 10.50 (Theora only, hangs on some systems), since 10.60 problem is fixed and additionally WeBM is supported.
Opera released an experimental Ogg Theora enabled build in 2007 as the very earliest attempt to support video in a browser ever, official HTML5 video support since 10.50 (Theora only, hangs on some systems), since 10.60 problem is fixed and additionally WeBM is supported.


As of 10.63, controls are visible even with JavaScript off, fully working for WebM, but for Theora only sound volume and already played time indicator do work, there is no total time and no progress / seeking. Opera can't play videos from local storage, only from the Internet if properly embedded in HTML5. There are tiny buffering / smoothness issues if CPU performance is insufficient to play in real time.
As of 10.63, controls are visible even with JavaScript off, fully working for WebM, but for Theora only sound volume and already played time indicator do work, there is no total time and no progress / seeking. Opera can only play media files when embedded in HTML5. There are tiny buffering / smoothness issues if CPU performance is insufficient to play in real time.


===Safari===
===Safari===

Revision as of 17:51, 1 February 2011

We'd like to hear detailed descriptions of problems viewing videos in standalone players and browsers. HTML5 and WebM especially are very new, and it's highly unlikely the experience in any browser is going to be free of hiccups quite yet. The more feedback we get about what doesn't work, the more we can do to make sure problems get fixed.

If you don't see your browser or player below, feel free to add it to the appropriate list. And to avoid any battles over natural pecking order, keep them in alphabetical order ;-)

A list of Ogg Theora players (without troubleshooting or discussion) with links to vendor pages can be found on the Theora Software Players page.

In-browser Playback

Hiccups not specific to any browser

Brief flash of beginning of video when changing resolutions

There are two basic ways of changing the video currently playing back in the current HTML5 spec, and both have some practical problems we'd like to see fixed before the spec is finalized.

The first way to change streams is to create a new video element via Javascript, wait for it to load, then replace the current video with the new one. Unfortunately, HTML5 gives no way to prevent the original video, even when stopped, from using all available bandwidth to keep buffering as fast as it can. This starves the replacement video of network access, causing a lengthy delay when loading. It looks very nice and seamless when it finally works, but can easily result is switching video streams taking 15-30 seconds or more.

The second option is to switch the pre-existing video element to a new stream. This is much faster as the original stream stops sinking bandwidth immediately, but upon loading it always starts from the beginning and in current browsers also displays the first frame, even if playback isn't started. After the load completes, then it's possible to seek forward to where the original stream started. It doesn't look as good, but it's much faster in practice.

Xiph's video playback scripting uses the second, faster option, so there's a brief flash back to the beginning of the video upon resolution switch.

No 'extra' controls [resolution switching, chapter navigation] on some browsers

The 'extra controls' that appear as a bar along the top of the video playback window are implemented using HTML5 <video> tag features, and as such can't work as written in browsers using the Cortado fallback applet. Cortado does support subtitles via the 'CC' button in the lower right of the playback area, and our Ogg streams include subtitle tracks.

Dual playback with Cortado

Unfortunate combinations of website and browser can result in Cortado playing the media independently in parallel with the browser's native playback.

Symptoms:

  • Two instances of the soundtrack plays concurrently, resulting in echo.
  • One soundtrack is in sync with the video, e.g. stops/restarts in sync with the video. The other is uncontrollable.
  • The media controls are the browser's native. Any evidence of Cortado are unseen.
  • Disabling Java fixes the problem.

Cases of Cortado getting in the way:

Firefox

Search for known Firefox Audio/Video bugs

Firefox versions 1.x, 2.x, 3.0.x

Firefox before version 3.5 (or 3.1 beta) did not include native support for Ogg or WebM. These browsers can play Ogg video via the Cortado applet if a Java runtime environment is installed. With Java installed, playback is seamless but does not have a full set of HTML5 features; resolution switching and chapter navigation are disabled. Cortado has native support for Ogg Kate subtitles.

Firefox 3.5.x

Firefox 3.5 was the first version of Firefox to ship with native Ogg playback. It features a full HTML5 feature set, though it is known to be relatively slow about seeking and navigation.

Seeking may work poorly if your connectivity to the media passes through a proxy which strips HTTP range requests.

On common GNU/Linux systems with pulseaudio, such as Ubuntu and Fedora, playback will halt and refuse to continue after pausing (and potentially seeking) and will not continue unless the page is completely reloaded due to Mozilla Bug#526411.

Controls / seeking don't work in unfullscreen mode if JavaScript is off, BUG#449358, not easy to fix, still "NEW". Since 3.6 a fullscreen mode exists not suffering from this problem. If controls are visible, they work properly (correct time is shown, seeking works if nothing else comes into the way) with both Theora and WebM.

Firefox can play videos from local storage too, if the file has proper extension. Both ".OGG" and ".OGV" are accepted, since 4.0 also ".WEBM", but for example ".WEB" will not work.

Firefox 3.6.x

Firefox 3.6 behaves similarly to FF3.5, but adds poster support and more robust Ogg stream navigation along with some bug fixes.

Seeking may work poorly if your connectivity to the media passes through a proxy which strips HTTP range requests.

On common GNU/Linux systems with pulseaudio, such as Ubuntu and Fedora, playback will halt and refuse to continue after pausing (and potentially seeking) and will not continue unless the page is completely reloaded due to Mozilla Bug#526411.

The (very nice) dimming effect that is applied to the rest of the page when the video is started, and is lifted when the video ends, is not reapplied when the video is restarted. This may or may not be by design, so I have not filed a bug report, but to me it felt inconsistent. [julietgolfbravo]

Seems to pass all tests (not sure about the 322x242 "not divisible by 16" - there is a black line ...).

High requirements to play (especially large) videos, behaves badly if hardware is insufficient to play in real-time.

Watching the clip in 480p quality works fine when watching from the very beginning, but when seeking to an unloaded scene, playback is very poor (Firefox 3.6.13, Windows XP Pro, 2.59 GHz CPU, 1.75 GB Ram here). Workaround: Pause the video and wait for a few seconds until pressing play again.

Firefox 4.0 (currently in beta)

Firefox 4.0 features a new Ogg playback engine that allows considerably faster stream navigation, as well as WebM support.

When I press the fullscreen button the video maximizes but the screen is black or displays some video corruption. The controls don't show up an I have to close the Firefox window. I'm running Windows XP sp3 and have a ati Radeon mobility x1150 video card with 10.2 catalyst drivers Firefox is beta6

My experience watching the excellent "A Digital Media Primer for Geek" using Firefox 4.0b3 on OSX 10.5.8 (WebM)

I watched half of the video with french subtitle perfectly. I had to pause. The day after I was unable to restart the video from where I paused. The movie were reloaded 4 times and I had the circle turning endlessely. I had to switch to 480 resolution to have the movie played again at the specific time I wanted. Hope this help.

Google Chrome

Search for video bugs in Chrome's bugtracker

Google Chrome added Ogg playback support in version [?], but it known to have serious bugs when seeking in Ogg streams; it also tends to lose the beginning of videos. Recent releases of Chrome support WebM, which works considerably better, though the playback framerate is often choppy/jerky (at least on Linux).

The "Save Video As" menu item re-downloads the video, even if it's fully cached.

Internet Explorer

Internet explorer 5, 6, 7, 8

Internet Explorer through version 8 has no support whatsoever for Ogg, WebM or the video tag. Normal installs do include Java support, however, so these browsers are able to play Ogg video through the Cortado applet. With Cortado, playback is seamless but does not have a full set of HTML5 features; resolution switching and chapter navigation are disabled. Cortado has native support for Ogg Kate subtitles.

Internet Explorer 9

Internet Explorer 9 (currently in alpha/beta) apparently at least somewhat supports the HTML 5 video tag, however it does not support Ogg or WebM playback out of the box. Microsoft has stated it will support Ogg and WebM 'if the codecs are installed on the system'. Presumably having the Open Codecs pack installed fufills this requirement and enables Ogg and WebM support (confirmation would be appreciated! If you have the Open Codecs Directshow filters installed, you should get full in-browser playback).

Internet Explorer 9 without Ogg/WebM support installed can presumably still play back Ogg video via the Cortado applet as in versions 8 and earlier (again, confirmation would be appreciated!)

Konqueror

Konqueror has native playback of HTML 5 audio/video. It supports all formats supported by Phonon, which supports all formats supported by its backend. Available Phonon backends include Xine and Gstreamer; backends using VLC and Mplayer are worked on.

Issues:

Netscape Navigator

Laugh if you must, but Navigator back to version 4 can play Ogg video via the Cortado applet.


Opera

Opera released an experimental Ogg Theora enabled build in 2007 as the very earliest attempt to support video in a browser ever, official HTML5 video support since 10.50 (Theora only, hangs on some systems), since 10.60 problem is fixed and additionally WeBM is supported.

As of 10.63, controls are visible even with JavaScript off, fully working for WebM, but for Theora only sound volume and already played time indicator do work, there is no total time and no progress / seeking. Opera can only play media files when embedded in HTML5. There are tiny buffering / smoothness issues if CPU performance is insufficient to play in real time.

Safari

Safari does not ship native support for Ogg or WebM video, however all versions can play Ogg video via the Cortado applet. With Cortado, playback is seamless but does not have a full set of HTML5 features; resolution switching and chapter navigation are disabled. Cortado has native support for Ogg Kate subtitles.

As of Safari 3.1, Safari supports full HTML5 Ogg video playback via the XiphQT Quicktime Components.

Standalone Players and Tools

Core Player

DUGL Player 0.44

Theora decoder seems fully compliant, but no sound yet, seeking / timing is bad.

FFMPEG / ffplay

As of release 0.6, ffmpeg supports WebM playback, and Ogg playback is solid with the exception of surround support (eg 5.1 and other surround encodings produced my modern Vorbis encoders will not play).

Prior to ffmpeg 0.6, WebM was not supported and Ogg video playback was broken due to a number of longstanding bugs caused by treating Theora as if it was just VP3 (eg, the 'sheet lightning acid trip' bug that caused the image to disintegrate into a shower of colored blocks). Many applications and video sharing sites (such as YouTube) are still using old versions of ffmpeg internally, and as such, they cannot handle Ogg video unless it is encoded in 'vp3 compatibility mode'.

Media Player Classic

Mplayer

Recent Mplayer versions have good native Ogg Theora playback support through libavcodec and since cca 2010-07 can additionally handle WebM playback through libavcodec too (ffmpeg libraries). OGG Dirac is not supported.

Mplayer has had a number of minor Ogg playback bugs in the past that mostly caused seeking or smoothness hiccups. Recent versions should have fixed all of the playback/seeking bugs of note.

OGG and Theora support has been inferior for years (but mostly worked with encoders from given era), improved at beginning of 2010, a regression existed from 2010-06 to 2010-09 (mirrored / messy top 16 lines, "nan:1" complaints, BUG#1788 BUG#1774 BUG#1771), now fixed.

Recently fixed issues:

  • 4:2:2 and 4:4:4 support (in previous versions they did "play", but looking "strangely") List discussion BUG#1487
  • Some videos encoded with recent (1.1) encoders complaining about "invalid frames" or hanging BUG#1664

Remaining issues:

  • Offset test fails, shows what shouldn't be visible BUG#1492, open since 2009-06-14
  • Output to YUV4MPEG always downsampled to 4:2:0 (flaw, no Bugzilla entry exists)

Helix Player (Real)

Quicktime

Quicktime supports Ogg and WebM playback and encoding through the XiphQT Quicktime Components. These components also add Ogg support to Quicktime-aware applications such as Final Cut and Final Cut Pro.

Totem

Totem supports Ogg and WebM playback via native support in gstreamer.

VLC

VLC has had good native Ogg Theora support since the GoldenEye release, Theora decoder seems fully compliant, tiny problems specific to some videos or systems (fixed?), video duration is reported badly or not at all. WebM support is available since 1.1.0, also OGG Dirac is supported, but problems with insufficient CPU performance.

Windows Media Player

WMP supports Ogg and WebM playback through the Open Codecs DirectShow filter pack.

Xine

Test videos