Réponse du support recue ce jour ci-dessous, je savais bien que ca marchait avant ...
Conclusion, si vous voulez continuer a regarder vos films encodés en DTS, ne passez pas à la 4.3 !
Dear user, Due to codec licensing issues, DTS transcoding has been removed from DSM. This change will cause videos embedded with DTS audio not to be played normally in Video Station and DS video. For streaming DTS videos in Video Station, we suggest you install VLC media player for playback. However, currently there is no officially supported 3rd party player supporting DTS integrated with DS video.
The codec licensing issues will also result in the removal of video transcoding from Media Server, if the file formats of videos to be played are not supported by your smart TV, we suggest you connect a DLNA-certificated set-top boxsupporting the formats in question to your TV. We sincerely apologize for the inconvenience this will cause.
If you have any suggestions or feedback regarding this change, please send them to our product teams at: http://www.synology.com/support/inquiry_form.php?type=1
We are sorry again for your inconvenience.