Why is Emby transcoding mp4/aac to mp4/aac?

[mobamoba 12]

I'm using Chromecast to play back a video and I noticed Emby was transcoding it and I'm trying to figure out why. It's just a 480p mp4. Shouldn't that play on Chromecast natively without transcoding? Is there something odd about this file that is telling Emby to transcode it? Here's the relevant info from my transcoding logs and thanks:

 

{"Type":"Default","Container":"mp4","Size":148395142,"Name":"480P/H264/AAC","RunTimeTicks":9475410000,"ReadAtNativeFramerate":false,"SupportsTranscoding":true,"SupportsDirectStream":true,"SupportsDirectPlay":true,"RequiresOpening":false,"RequiresClosing":false,"VideoType":"VideoFile","MediaStreams":[{"Codec":"h264","Language":"und","IsInterlaced":false,"BitRate":1087917,"BitDepth":8,"RefFrames":4,"IsDefault":true,"IsForced":false,"Height":448,"Width":714,"AverageFrameRate":29.93837,"RealFrameRate":29.97003,"Profile":"Main","Type":"Video","AspectRatio":"17:12","Index":0,"IsExternal":false,"IsTextSubtitleStream":false,"SupportsExternalStream":false,"PixelFormat":"yuv420p","Level":30,"IsAnamorphic":false,"IsCabac":false},{"Codec":"aac","Language":"und","IsInterlaced":false,"ChannelLayout":"stereo","BitRate":159988,"Channels":2,"SampleRate":48000,"IsDefault":true,"IsForced":false,"Profile":"LC","Type":"Audio","Index":1,"IsExternal":false,"IsTextSubtitleStream":false,"SupportsExternalStream":false,"Level":0}],"PlayableStreamFileNames":[],"Formats":["mov","mp4","m4a","3gp","3g2","mj2"],"Bitrate":1252885,"RequiredHttpHeaders":{}}
 

[TolkienBard 58]

Transcoding will happen when bitrates don't match as well.

[Luke 42078]

that looks like a file that should direct steam, so i'm not sure. as TolkienBard said, could be the bitrate setting. Best thing to do is enable debug logging, try it again and grab the server log.

[mobamoba 12]

Okay. I set debugging to enable, restarted the server, and the Chromecasted the same file from before. I've attached the server log and transcoding log from that session. Thanks.

server-63569016278.txt

transcode-d7661b73-5e38-417a-9285-9241a018c1cd.txt

[Luke 42078]

For this file it's due to the Cabac value but i'm going to remove that check. It will be resolved with the next release of the server.