mkvmerge option

[baconharvester]

There is an option in mkvmerge GUI for the audio sections of mkv files. The option is a checkbox that says AAC is SBR/HE-AAC/AAC+. If I see that one of my files has audio with A_AAC/MPEG4/LC/SBR, should I check the option when merging the file?

[celtic_druid]

Sounds like you are remuxing an mkv file, so no. With mkv's and mp4 sources it will be autodetected. The option is for raw aac streams where there is no header telling mkvmerge what it needs to know.

[baconharvester]

Is it bad if I did check it for one of the mkv files I had? Or does it not affect the audio quality at all?

[celtic_druid]

If a decoder doesn't know that it is he-aac (when it is), then it will decode without the SBR part. This will badly effect the audio quality. Fact is that some decoders might get it right anyway. Plus from the sounds of it all you are doing is ticking a box that essentially would have been auto-ticked anyway. Like I said, you shouldn't need to worry about the option unless you are muxing a raw aac file.