Animate requires FLV video to be shown in timeline, yet Adobe discontinued support for FLV

after posting the above, i tested and found vlc doesn't do a good job converting.  it does convert and it does play in vlc but animate doesn't handle the converted file properly.  so, i'd look for another conversion tool, if it's important.

use the free vlc player:

Steps to Change MP4 to FLV Using VLC Media Player:

Step 1: Launch VLC Media Player, head over to the “Media” menu, and click on “Convert/Save…”

Step 2: From the “File” section tab, click on “Add…” to import an MP4 file, expand the “Convert/Save” drop-down menu and select the “Convert Alt+O” option.

Step 3: VLC does not have a preset MP4 to FLV profile so create one using the “Create a new profile” but and give it a suitable name.

Step 4: Choose a saving directory, an appropriate filename with the “.flv” extension, and then click on “Start” to convert your MP4 file to FLV format.