Adobe Flash

Installation
There are several methods of using Flash Player on Gentoo. Some will work in all web browsers, while others only work in a select few.

Adobe Flash
Adobe provides a Flash Player for NPAPI-based browsers (e.g. Firefox, Konqueror) on Linux. However, Adobe has discontinued the development of the NPAPI-based Flash Player on Linux, but will provide security updates for five years after the release of Flash Player 11.2.

To use Flash Player with a NPAPI-based browser, install Adobe Flash:

After installation, start/restart the web browser.

Google Chrome
Google Chrome includes a PPAPI-based Flash Player which is actively maintained by Adobe. To use Flash Player, install Google Chrome:

This will not enable Flash Player for use in browsers outside of Google Chrome, but a plug-in can be installed to enable the PPAPI-based Flash Player with NPAPI-based browsers. This is done with freshplayerplugin (see the section below).

freshplayerplugin
freshplayerplugin is a NPAPI wrapper for the PPAPI-based Flash Player. To use the PPAPI-based Flash Player with a NPAPI-based browser, install with the   USE flag:

Or install Google Chrome:

Next, install freshplayerplugin:

After installation, start/restart the web browser.

Without Flash Player
An alternative to using Flash Player when only playing video streams from YouTube, Vimeo, Twitch, Internet TV stream, etc., is to install with the   USE flag, and  or  with the   USE flag. The  USE flag allows  to work in mpv, and the   USE flag allows FFmpeg/Libav to open https:// streams. Next, install the Open-with Firefox add-on and configure it in the following way:


 * Open about:openwith, select Add...
 * In the dialog select a video streaming capable player (e.g. ).
 * (Optional step) Choose how to display the dialogs using the left panel of Open-with add-on.
 * Right click on links or visit pages containing videos. If the site is supported, the player will be open as expected.

The same procedure can be used to associate other video downloaders such as youtube-dl.

External resources

 * Adobe Flash Player on Arch Linux Wiki