The　increasing　popularity　of　video　(i.e.,　audio-visual)　applications　or　services　over　both　wired　and　wireless　links　has　prompted　recent　growing　interests　in　the　investigations　of　quality　of　experience　(QoE)　in　online　video　transmission.　Conventional　video　quality　metrics,　such　as　peak-signal-to-noise-ratio　and　quality　of　service,　only　focus　on　the　reception　quality　from　the　systematic　perspective.　As　a　result,　they　cannot　represent　the　true　visual　experience　of　an　individual　user.　Instead,　the　QoE　introduces　a　user　experience-driven　strategy　which　puts　special　emphasis　on　the　contextual　and　human　factors　in　addition　to　the　transmission　system.　This　advantage　has　raised　the　popularity　and　widespread　usage　of　QoE　in　video　transmission.　In　this　paper,　we　present　an　overview　of　selected　issues　pertaining　to　QoE　and　its　recent　applications　in　video　transmission,　with　consideration　of　the　compelling　features　of　QoE　(i.e.,　context　and　human　factors).　The　selected　issues　include　QoE　modeling　with　influence　factors　in　the　end-to-end　chain　of　video　transmission,　QoE　assessment　(including　subjective　test　and　objective　QoE　monitoring)　and　QoE　management　of　video　transmission　over　different　types　of　networks.　Through　the　literature　review,　we　observe　that　the　context　and　human　factors　in　QoE-aware　video　transmission　have　attracted　significant　attentions　since　the　past　two　to　three　years.　A　vast　number　of　high　quality　works　were　published　in　this　area,　and　will　be　highlighted　in　this　survey.　In　addition　to　a　thorough　summary　of　recent　progresses,　we　also　present　an　outlook　of　future　developments　on　QoE　assessment　and　management　in　video　transmission,　especially　focusing　on　the　context　and　human　factors　that　have　not　been　addressed　yet　and　the　technical　challenges　that　have　not　been　completely　solved　so　far.　We　believe　that　our　overview　and　findings　can　provide　a　timely　perspective　on　the　related　issues　and　the　future　research　directions　in　QoE-oriented　services　over　video　communications.