Flash players support but SWF Tools does not support MP4 playing

SWF Tools already supports arbitrary file formats so no update is needed. The only "trick" is that you may need to help SWF Tools determine what it needs to do.

When SWF Tools processes a file it looks at the extension to try and determine what action it should take. The available actions are listed in the documentation. If SWF Tools encounters a file extension it doesn't know about then it will assign it the action swftools_media_display_list, and the player configured for that will be used. On the settings page you assign the handler for that action, so if you set Wijering or FlowPlayer that's all you need to do.

For example, if you were to put [swf file="video.mp4"] in your node then SWF Tools doesn't know that mp4 is video, so it is given the mixed media action. On the file handling page of SWF Tools you assigned the player you want (e.g. Wijering, FlowPlayer), and that's it - the content will play.

If you want you can force a specific action by specifying it in the input filter. When SWF Tools was first written video was generally flv, so the video action name reflects that, and you would specify the video action by writing [swf file="video.mp4" action="swftools_flv_display"]

However, in most cases simply assigning your preferred media player as the handler for mixed media should be enough.

There's an important note here though - not all video files are the same! FlowPlayer and Wijering may playback some mp4 files but you only hear audio. This is to do with the encoding of the file, so if you hear sound, but don't see the video, then it is most likely not SWF Tools that is the issue!

in most cases simply assigning your preferred media player as the handler for mixed media should be enough

yes. it works without problem

Youtube offer a convert swf to mp4 tutorial: http://youtu.be/1Q-iHeHgPmk