jpg     image/jpeg
jpeg    image/jpeg
gif     image/gif
png     image/png
ico     image/vnd.microsoft.icon
mp3     audio/mpeg
ogg     audio/ogg
wav     audio/wav
webm    video/webm
ogv     video/ogg
mp4     video/mp4
pdf     application/pdf
docx    application/vnd.openxmlformats-officedocument.wordprocessingml.document
xlsx    application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
pptx    application/vnd.openxmlformats-officedocument.presentationml.presentation
txt     text/plain