Sorry, but *.swf isn't supported anymore, you must render single frames, and then using another software (such as VirtualDub or Adobe Premiere) to generate a video by importing the rendered frames.
Since there are so few updates in this topic I'll add my 2 cents... (Use of "VirtualDub" and "Shotcut"... both FREE!)
So far it seems that VirtualDub is the easiest tool for assembling rendered frames! Place them in a single directory, and make sure they are numbered sequentially. Then "Open Video File" and navigate to your directory. Pick out the first image, the program grabs the rest.
Next set your output video parameters such as fps (frames per second). Then save it as an AVI.
Longer than one set of images??? Render separate blocks of images, and intentionally generate extra frames at the beginning and end of each. Put each set of rendered images in their own folder, and use VirtualDub to turn each block into a movie clip.
Finally, open these one at a time in Shotcut, a free and very capable video editor. It can handle many tracks of videos and alignment with audio. In the current process, open a video AVI file and once loaded, click/drag it to the Timeline editor (at the bottom). Drop the first one there and it automatically goes to the beginning. As you open the next clips, drag them into the timeline. Drag them slowly to the existing clip/s and when close it will -snap- into place. Drop it there...
For best effect, follow that initial drop of additional clips with the action of clicking on the clip and slowly dragging it to the left so it goes over the previous entry. A popup box will show you how much time is being overlapped. This will automatically cause a fade-out of the one clip, into the fade-in of the new clip.
Do that for all your clips.
When you are ready, set the pointer at the beginning and click play. Adjust if necessary. Finally you need to look at your Format listing and pick out your choice. I usually pick out "mp4"... Your frame rate was established in the AVI, and it should show the same rate here. Click "Encode File" and give it a name, including the mp4 extension. When you click save, it renders everything into your output movie. Test it using your video player.
There's a lot of info out there to learn more about Shotcut, synching audio, and other editing methods.