samsung s4 dont play mp3 or a video when talking

if i will speaking with someone in call ofcourse the system it dont allow me play an mp3 or video mp4 for hearing both of us(me and my friend) a favorite song or favorite video.say ''playing video or game in a call its not possible''something for solution??????thanks

via Forums de téléphone cellulaire (en français) http://cellphoneforums.net/fr/samsung/t365291-samsung-s4-ne-jouent-pas-mp3-ou-une-vid%C3%A9o-lorsque-l-on-parle.html