Aye PA,
without looking into the filter details of your ffmpeg cmd, the ffastrans version looks fine on quick peek. It might just be a good idea to use a STATIC variable instead of hardcoding UNC paths directly in processors but thats kind of an advanced topic.
Regarding your workflow, you cannot have 2 Watchfolders in one job, they would end up as 2 standalone jobs, one not knowing anything about the other. Here is why (look at workflows_equal.png picture):
https://ffastrans.com/frm/forum/viewtop ... =849#p3565
You must start your workflow using 1 watchfolder and it is best to trigger jobs only when the LAST file arrived. So your user needs to throw to files into the folder, one called *_MOD1.mp4 *_MOD2.mp4 - in this case you would set to watch only for *_MOD2.mp4 (if that one is expected to be coming in after *_MOD1.mp4.
As it is not simple to merge branches after a split, it is best if you do all processing in serial, it goes like this:
watchfolder -> Audio extract2 -> Populate1 -> audio extract1 -> merge
The Populate1 node is the key, you need to save the current s_source and set s_source to the the other source file. E.g.
%s_mod_2% = %s_source%
%s_source% = "%s_job_work%\%s_original_name%_MOD1.wav"
You need to understand what value s_source has at any point in the workflow. After each Audio Extract processor, s_source points to the internally generated .wav file in the "work_dir". So after the second Audio Extraction, s_source points to the second generated wav file in the job_work_dir.
Last, in the ffmpeg command you posted, you would basically replace
"%s_job_work%\%s_original_name%_MOD1.wav" by "%s_source%"
and
"%s_job_work%\%s_original_name%_MOD2.wav" by "%s_mod_2%"
More infos about s_source:
https://ffastrans.com/frm/forum/viewtopic.php?f=5&t=849
https://www.ffastrans.com/wiki/doku.php ... _variables