I'll try to keep this feature request short and simple.   When the Emby server needs to transcode audio to make it compatible for the Emby client, it will use a hardcoded value for the bitrate that cannot be changed. For example, if the audio gets transcoded to Dolby Digital AC-3, it will always use a bitrate of 384 kb/s. This value cannot be changed, even though Dolby Digital AC-3 allows a maximum bitrate of 640 kb/s. Although 384 kb/s is a decent compromise between quality and data, it is v