[Freeswitch-users] question on file string in playback

When using the playback application (or play_and_get_digits etc) do I need to specify the full path to the file under the base sounds directory, including the sample rate (e.g. 8000). It’s a bit cumbersome to have to put the sample rate into the file string since that is dynamically determined at call set up, and I _thought_ that freeswitch had the ability to automatically factor that in when locating the file. However, I can’t find examples that do that — am I wrong, and must I somehow concoct a file string that will be different per call if different codecs are chosen?