Hello, I'm wondering if it is at all possible to easily change the audio stream from dts to ac3 640.
I've been doing a lot of reading around and as someone who's not exactly computer literate it's becoming quite a hassle for me to figure out a solution to get my audio in exactly that format, ac3 640.
Any help would be greatly appreciated.
DTS has many flavors: standard 5.1-channel DTS, DTS-ES, DTS Neo, DTS 96/24, DTS-HD HRA, DTS-HD MA, DTS:X, ...
So your simple question is more complicated then it seems.
See DTS (https://en.wikipedia.org/wiki/DTS_%28sound_system%29#DTS_Technologies):
What did you try with Menu audio: in Select Track?
The maximum bitrate for FFmpeg (lavcodec) based audio codecs in Avidemux is 448 kbps (https://github.com/mean00/avidemux2/blob/master/avidemux_plugins/ADM_audioEncoders/lavcodec/audioencoder_lavcodec.cpp#L529). It was lower before February 2014: http://avidemux.org/smif/index.php?topic=16008.0 (http://avidemux.org/smif/index.php?topic=16008.0). If you are able to build Avidemux yourself, adding an entry to audioencoder_lavcodec.cpp should be straightforward, ffmpeg 3.0.3 supports bitrates up to 640 kbps for ac3 (https://github.com/FFmpeg/FFmpeg/blob/release/3.0/libavcodec/ac3enc.c (https://github.com/FFmpeg/FFmpeg/blob/release/3.0/libavcodec/ac3enc.c)). Otherwise use ffmpeg at command line with
-c:a ac3 -b:a 640k
for the audio codec part of the command.