Transcoding/Container Change

[josephdouce 3]

does the server transcode even if a container change would be sufficient?

 

e.g. .mkv with h264 and aac being played on chrome shows "transcoding due to unsupported container" is it ACTUALLY transcoding or is it copying the streams.

ffmpeg.exe -i inputfile.mkv -c:v copy -c:a copy outputfile.mp4

or 

ffmpeg.exe -i inputfile.mkv -c:v h264 -c:a aac outputfile.mp4  

as the second one would result in the file being transcoded unnecessarily.

Edited December 21, 2017 by josephdouce

[Luke 42082]

The first one is copying, second one is converting.

[josephdouce 3]

The first one is copying, second one is converting.

Yes but the first one also changes the container.

 

Sent from my SM-G920F using Tapatalk

[Luke 42082]

Correct.

[josephdouce 3]

So if there is a file on the server that is a .mkv with h264 and AAC will the server transcode it for Chrome or will it just change the container?

Because if you give a h264 file to ffmpeg and tell it to transcode to h264 it doesn't necessarily copy the stream.

It will transcode with the default settings which is much more overhead then simply copying the steam to a new container.
 

I have a script here that I use to convert that checks the video and audio streams, and if the audio is mp3 or aac it copys the stream and if the video is h264 it copys the stream, avoiding un-necessary transcoding.

 

https://github.com/josephdouce/ffmpeg-library-transcode/blob/master/ffmpeg_convert.ps1

Edited December 21, 2017 by josephdouce

[Luke 42082]

Yes it will always stream copy when possible, and no that's not true that at default settings it will always transcode. Thanks.

[josephdouce 3]

Sorry that was miss leading I meant ffmpeg not the server.

[ebr 16187]

Hi.  You are obviously familiar with ffmpeg so, in the future, you can examine the ffmpeg logs generated by Emby when you play something (that involves ffmpeg) and you will see exactly what it is doing.

 

Thanks!