Where did you install Firefox from? Help Mozilla uncover 3rd party websites that offer problematic Firefox installation by taking part in our campaign. There will be swag, and you'll be featured in our blog if you manage to report at least 10 valid reports!

搜尋 Mozilla 技術支援網站

防止技術支援詐騙。我們絕對不會要求您撥打電話或發送簡訊,或是提供個人資訊。請用「回報濫用」功能回報可疑的行為。

Learn More

Cannot play mp4 files

  • 5 回覆
  • 2 有這個問題
  • 20 次檢視
  • 最近回覆由 FredMcD

more options

On Windows Vista, firefox 38.0.5 cannot play mp4 files. Both MPC-HC and Windows Media Player can play mp4 files. I have ffdshow installed.

These are enabled:

   media.windows-media-foundation.enabled
   media.directshow.enabled

Results from https://www.youtube.com/html5 show:

Disabled: H.264, MSE & H.264, MSE & WebM VP9

Enabled: HTMLVideoElement, Media Source Extensions, WebM VP8

Youtube videos are also locked at 360p using the html5 player.

OGG / WebM files play fine.

On Windows Vista, firefox 38.0.5 cannot play mp4 files. Both MPC-HC and Windows Media Player can play mp4 files. I have ffdshow installed. These are enabled: media.windows-media-foundation.enabled media.directshow.enabled Results from https://www.youtube.com/html5 show: Disabled: H.264, MSE & H.264, MSE & WebM VP9 Enabled: HTMLVideoElement, Media Source Extensions, WebM VP8 Youtube videos are also locked at 360p using the html5 player. OGG / WebM files play fine.

由 chuck1899 於 修改

所有回覆 (5)

more options

Can anyone help?

more options

You can check these media prefs on the about:config page:

  • media.windows-media-foundation.enabled
  • media.directshow.enabled
more options

They are both enabled.

Refresh Firefox - reset add-ons and settings Refreshing Firefox didn't seem to do anything either.

由 chuck1899 於 修改

more options

It's been a month and even with Firefox 40.0.3 it still doesn't work.

Why?

more options

Sometimes, messages get lost from inactivity. Sorry.

check this:

  • see if there are updates for your graphics drive drivers

https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

  • disable protected mode in the Flash plugin (Flash 11.3+ on Windows Vista and later)

https://forums.adobe.com/message/4468493#TemporaryWorkaround

  • disable hardware acceleration in the Flash plugin

https://forums.adobe.com/thread/891337 See also: