Since Poodll version 3.1.02 (Build 2018041003) it is possible to customize the placeholder audio and video files that play while you are waiting for the recording to convert. For audio you should prepare an MP3 file and for video an MP4 file.
Visit the Poodll advanced settings page
Site administration -> Plugins -> Filters -> Poodll -> Advanced settings
Upload your file(s) into the placeholder file area(s)
(0ptional but good) Set the duration of the recording
The unit of the value you enter should be seconds, and to at least 1 decimal place. The Poodll players uses this to see if the loaded media is a placeholder. And if so, they will check every 15 seconds for the arrival of the converted file. If you do not specify this, nothing bad will happen. But the user may need to load the page to check if their file is ready
You might be wondering how to get such a detailed duration of your placeholder file. (And be warned different browsers may report a different length. We are talking about you, Firefox). We have prepared a special audio player template with a "Fetch File Duration" button. To use this, first create a template from the "audio file duration" or "video file duration" presets. (see here for how to use presets). Then set the template as the handle for audio or video on a dummy page on your site. (see here for how to set a template to handle mp3/mp4). Then upload your file(s) to that page (add them as "links" not full blown players). Poodll will show the file and a button like this:
Save the settings
good luck