See? this is the problem I was pointing o9ut and have no idea if tsdec could sync the CW to an encrypted file.
Apprently it need the time stamps or may not even use them .
As per readme:
****TSDEC will now try to sync, meaning trying to find TS packets matching to a
cw. If the recorded ts file was ok and you have the CWs from the correct
program and time (this is the problem,I think), you see "sync at packet..." and tsdec should write the
decrypted file recording_decrypted.ts on your disk. ****
I imagine tsdec could check for correct decryption and when failed,it uses the next CW ,but then video packet can be corrupted and never decrypt,while tsdec would change to the next CW when it should not.
Again,an uneducated guess from my part.
UPDATE
the readme actually tells how it works, and how it determine to use next CW,so,is clear for me now.
Thank you
Too many variables that can disrupt the decryption offline,as per the original question on this thread.