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html5 videos do not play anywhere but on youtube?

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  • 13 이 문제를 만남
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  • 최종 답변자: JohnnyBB

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No matter what options I change (I tried everything under about:config, I even completely reinstalled firefox), html5 videos don't play (format not supported, wrong mime type etc.). On youtube however, the html5 player works fine.

Examples of videos not working: http://techslides.com/demos/sample-videos/small.mp4 http://techslides.com/demos/sample-videos/small.webm http://techslides.com/demos/sample-videos/small.ogv http://www.html5videoplayer.net/html5video/mp4-h-264-video-test/ http://www.webmfiles.org/demo-files/

My Win7 can play everything - I do not use Windows Media Player and normally keep those features deactivated but actually tried activating all Windows Media features (I normally use the K-Lite codec pack and in my desperation also tried CCCP). It did not help. Downloading the videos lets me play them without problems.

All my media.* preferences in about:config have the default value, and I tried changing stuff - the most that achieves is just disabling html5 videos entirely - which is not a solution.

I also deactivated all addons/plugins, I restored Firefox, uninstalled and reinstalled it, even tried the 64bit developer version.

https://html5test.com/ tells me that my firefox supports everything but DRM and MPEG-4 ASP under video. http://detectmybrowser.com/ tells me I can play ogg but not h264 or webm. https://www.youtube.com/html5 tells me my firefox supports everything youtube needs (if I flip media.mediasource.webm.enabled, of course).

Again, on youtube everything works (right-clicking the videos gives me the "About the HTML5 player" option), everywhere else (as far as I have seen) I get the "format not supported/wrong mime type error.


Firefox 37.0.2 on Windows 7, I started noticing the problem with the 37 update - I guess because firefox switched to html5 instead of flash as default? I've been using html5 on youtube since it became possible. Also, my plugin-container crashes whenever I close firefox, I have tried clearing cookies/history/cache (besides resoting/reinstalling, which should include this) since that was a suggested solution. The problem always comes back, no matter what sites were loaded. If I exit firefox only seconds after opening it the plugin-container might not crash. No idea if this is related to the html5 issue.

So, any ideas I can try to make html5 videos work?

No matter what options I change (I tried everything under about:config, I even completely reinstalled firefox), html5 videos don't play (format not supported, wrong mime type etc.). On youtube however, the html5 player works fine. Examples of videos not working: http://techslides.com/demos/sample-videos/small.mp4 http://techslides.com/demos/sample-videos/small.webm http://techslides.com/demos/sample-videos/small.ogv http://www.html5videoplayer.net/html5video/mp4-h-264-video-test/ http://www.webmfiles.org/demo-files/ My Win7 can play everything - I do not use Windows Media Player and normally keep those features deactivated but actually tried activating all Windows Media features (I normally use the K-Lite codec pack and in my desperation also tried CCCP). It did not help. Downloading the videos lets me play them without problems. All my media.* preferences in about:config have the default value, and I tried changing stuff - the most that achieves is just disabling html5 videos entirely - which is not a solution. I also deactivated all addons/plugins, I restored Firefox, uninstalled and reinstalled it, even tried the 64bit developer version. https://html5test.com/ tells me that my firefox supports everything but DRM and MPEG-4 ASP under video. http://detectmybrowser.com/ tells me I can play ogg but not h264 or webm. https://www.youtube.com/html5 tells me my firefox supports everything youtube needs (if I flip media.mediasource.webm.enabled, of course). Again, on youtube everything works (right-clicking the videos gives me the "About the HTML5 player" option), everywhere else (as far as I have seen) I get the "format not supported/wrong mime type error. Firefox 37.0.2 on Windows 7, I started noticing the problem with the 37 update - I guess because firefox switched to html5 instead of flash as default? I've been using html5 on youtube since it became possible. Also, my plugin-container crashes whenever I close firefox, I have tried clearing cookies/history/cache (besides resoting/reinstalling, which should include this) since that was a suggested solution. The problem always comes back, no matter what sites were loaded. If I exit firefox only seconds after opening it the plugin-container might not crash. No idea if this is related to the html5 issue. So, any ideas I can try to make html5 videos work?

모든 댓글 (10)

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With respect to plugin-container.exe, it is used for Flash, Java, and other plugins, but not for HTML5 video, since that is handled without a plugin.

On Windows 7, Firefox uses Windows Media Foundation to decode MP4 videos. Could you check your preferences for enabling MPEG support? You can find those here:

(1) In a new tab, type or paste about:config in the address bar and press Enter. Click the button promising to be careful.

(2) In the search box above the list, type or paste media and pause while the list is filtered

(3) {for Windows newer than XP} If the media.windows-media-foundation.enabled preference is bolded and user set to "false", double-click it to switch it to true

(4) {for Windows XP} If the media.directshow.enabled preference is bolded and user set to "false", double-click it to switch it to true

If you changed these settings, does that make any difference? I'm not sure whether the change takes effect immediately or after you exit Firefox and start it up again.


The issue of a wrong MIME type is different, and you should not encounter that on mainstream video sites unless a proxy or some security software is changing the headers sent by the server which indicate the media content type (e.g., audio/mpeg).

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Oops, didn't read your post carefully enough as you already have verified that Windows Media Foundation is enabled.

And you also can't play webm, which Firefox can handle using its own code...

Could you open the following page and then open the web console (Ctrl+Shift+k) in the lower part of the tab. Click Network in the top row, and then reload.

http://www.webmfiles.org/demo-files/

Then finally scroll down to the demo video and play it. What do you see for the request/response? I have attached a screen shot for comparison.

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Lots of the GETs are yellow - no idea what that means, but the video itself is green and missing its actual content (0KB)?

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The status code 304 indicates the file was found in and loaded from the cache, so that's not a problem.

If you right-click > Inspect Element (Q) on the player area, does it show the proper content type in the < source > tag? (Screen shot example attached.)

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Yes, exactly as on your screenshot.

The console also says that all candidates for the resource could not be loaded.

If I open the video in its own tab (http://video.webmfiles.org/big-buck-bunny_trailer.webm) and look at the network analysis the file is never downloaded (0KB); if I resend the request the file is actually downloaded but still not played.

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Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window

Try to delete possible user.js and numbered prefs-##.js files and rename (or delete) the prefs.js file to reset all prefs to the default value including prefs set via user.js and prefs that are no longer supported in the current Firefox release.


Create a new profile as a test to check if your current profile is causing the problem.

See "Creating a profile":

If the new profile works then you can transfer files from a previously used profile to the new profile, but be cautious not to copy corrupted files to avoid carrying over problems.

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cor-el: Just (re)tried everything you suggested, no change. Whether in safe mode or a new profile, html5 videos don't play (...and the plugin-container still crashes on exit). As I said, I also tried restoring/resetting as well as reinstalling before.

Firefox also just updated to 38, which also did nothing.

글쓴이 JohnnyBB 수정일시

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The HTML5 media player doesn't use the plugin-container process as posted above, so if this process crashes then a plugin is used and not the HTML5 media player.

You can set all plugins to "Ask to Activate" on the "Firefox/Tools > Add-ons > Plugins" page.

Are you using "Clear history when Firefox closes" to clear the cookies?

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, passwords, and other website specific data.

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To see whether it makes any difference with the shutdown crashes, could you set everything except Silverlight and Shockwave Flash to "Never Activate" on the Add-ons page. Either:

  • Ctrl+Shift+a
  • "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins.

For Silverlight and Shockwave Flash, try "Ask to Activate" if those are not already set to that.


As for the videos, I don't understand why Firefox doesn't think headers matching the expected type are a supported content type. It should work.

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I am well aware that the html5 media player doesn't use the plugin-container, it's just that it's a weird problem. Now that I think about it it probably showed up along with the html5 troubles (a few weeks ago, as I said maybe with the 37 release). And I did go further than "Ask to Activate" and tried setting them all to "Never Activate" - the process still crashes on exit.

Concerning my history settings: I normally do not clear the history on exit, I tried activating it just now, restarted Firefox a few times - no change. Besides, I tried all that before. I installed a separate edition of Firefox (the dev version) and used a new profile - still the same issues.

I am using Sync for tabs, bookmarks and passwords - other than that I practically reset Firefox to a completely new install.

So what does that leave? Is there some registry entry that stuck or some setting an uninstall did not remove, some setting that every Firefox install uses? What can cause Firefox to NOT play html5 media, even though everything looks fine in the network analysis (other than the video just NOT loading)?

글쓴이 JohnnyBB 수정일시