Code fix looping mp4 video seamless no gap

Exoplayer is used in current Android Application. Looping video works fine, but there is a gap in audio, pause, or drop in sound at the begging of the loop. Not sure if some type of pre buffer of video/audio is needed, but looking for someone who knows how to solve or fix the issue. For example there is a video and audio of wind pushing clouds across the sky with other scenery in the background. As video starts over, you will hear the sound cut out, and then continue as normal while the video continues to play. It makes it seem like there is something wrong with the app. But app works fine, just need this one part to be fixed, and looking for someone with experience who can just jump in and fix the issue easily because they have done it before.