No need for transcoding mp4 stream for Chrome (m4b)

[yermak 1]

Version 3.5.3.0

OS: Ubuntu 18.04.1 LTS hosted in Hyper-V

Chome: Version 71.0.3578.98 (Official Build) (64-bit)

 

Audiobook created in m4b format created with ffmpeg using 

-movflags +faststart

After requesting playback embyserver.txt:

2019-01-07 22:19:01.437 Info HttpServer: HTTP GET http://192.168.1.222:8096/emby/Audio/56fe59bef25ea644b919242332aeaafd/hls1/main/107.ts?UserId=cf7907b74d66444e961dfa276f410195&DeviceId=TW96aWxsYS81LjAgKFdpbmRvd3MgTlQgMTAuMDsgV2luNjQ7IHg2NCkgQXBwbGVXZWJLaXQvNTM3LjM2IChLSFRNTCwgbGlrZSBHZWNrbykgQ2hyb21lLzcxLjAuMzU3OC45OCBTYWZhcmkvNTM3LjM2fDE1NDY2NzU5ODc3OTA1&MaxStreamingBitrate=140000000&Container=opus,mp3|mp3,aac,m4a|aac,flac,webma,webm,wav&TranscodingContainer=ts&TranscodingProtocol=hls&AudioCodec=aac&PlaySessionId=1546897003224&StartTimeTicks=0&EnableRedirection=true&EnableRemoteMedia=false&SegmentContainer=ts&AudioBitrate=384000&TranscodeReasons=ContainerNotSupported,AudioCodecNotSupported.UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/71.0.3578.98 Safari/537.36

2019-01-07 22:19:01.444 Info HttpServer: HTTP Response 200 to 192.168.1.172. Time: 1141ms (slow). http://192.168.1.222:8096/emby/Packages/Updates?PackageType=UserInstalled

 

It seems that brawser just did not pass m4b as supported container.

 

Transcoding log attached.

 

Assuming that m4b is the same format as m4a, it should be played without forced transcoding, even if there is a need for transcoding then -a copy should be used instead of force reincoding to higher bitrate.

 

Please also note flags passed to ffmpeg "-strict experimental -ab 384000" are not accurate, as ffmpeg does not require -strict experimental any longer (aac is quite stable) and bitrate is hardcoded as orginal bitrate was lower, thus probably should be just omited. 

 

 

P.S. Attached the file

 

m4b-transcoding.txt

Edited January 7, 2019 by yermak

[Luke 39642]

Hi there, can you please attach the ffmpeg log? thanks !

[yermak 1]

Luke, updated original post.

[Luke 39642]

Ok, I've got the direct play worked out for the next release, thanks.