While the Firefox has a very good support for HTML5 standards, you may have noticed that it does not support all the features required to play videos on YouTube without having Adobe Flash Player installed. It does support the required HTMLVideoElement feature, but some videos do not play anyway. Why is this happening;
These videos require this feature which is disabled by default on Firefox's Media Source Extensions page. By default, this option is disabled by Firefox developers, and thus the popular program tourIt is not able to play HTML5 video streams. To enable the feature, follow these steps:
Open it Browser Firefοx και πληκτρολογήστε το παρακάτω στη γραμμή διευθύνσεων:
about: config
Note: A window will appear with a rather humorous dialog-pronotice. "Caution! You may void the product warranty”. Good one huh; Fear not the developers of the popular browser are just kidding you…
Of course, it's a good idea to know what you are doing before you start to change the values on the settings page.
Click on "I will be careful, I promise!" to continue.
Enter the word "MediaSource" (excluding the quotes we use) in the search box
You will see the media.mediasource.enabled parameter set to false. Double click on it to change its value to true.
Restart Firefox to enable the feature.
Now open some of the YouTube videos that are in HTML5 and were not originally played. They should play without problems.
I did a stupid thing and you do not save the new videos I see on youtube. We do not remember the command