Always use open formats:
Audio: (music or voicemails) WAV or MP3
Video: use open formats like MPEG-2 (.mpg, .mpeg) and MPEG-4 (.mp4)
Photos: TIFF (*.tif), JPEG2000 (*.jp2) , PNG (*.png) , JPEG/JFIF (*.jpg) , BMP (*.bmp)
Recommended Digital Formats