If your rendition server does not possess all the mime types that you wish to use, it is then still possible that the rendition server could convert your file.
In the specific case of video/image conversion, the full list of files that can opened by imagemagick/ffmpeg is long.
If you wish to add this mime type, just modify the arender-rendition.xml file of the conf/ folder of the rendition server.
As an example, if you wish to add the mime type image/x-bmp:
<property name="factories"> ... <entry> <key> <value>image/png,image/jpeg,image/gif</value> </key> <ref bean="imageFactory" /> </entry>
<property name="factories"> ... <entry> <key> <value>image/png,image/jpeg,image/gif,image/x-bmp</value> </key> <ref bean="imageFactory" /> </entry>
For the video mime types the factory concerned is the videoConversionFactory, where you can add each mime types desired.