On 3 September 2013 14:48, eryksun <eryk...@gmail.com> wrote: >> It occurs to me that another possibility is if ffmpeg isn't really an >> .exe on PATH but rather a .bat file or something. In that case >> os.system or subprocess shell=True would pick it up but subprocess >> shell=False might not. I say "might" because at least on some version >> of Windows CreateProcess can run .bat files directly but I've never >> seen this documented anywhere. > > cmd tries each PATHEXT extension, but CreateProcess only tries .exe, > and finds ffmpeg.exe. > > As to batch files, "Windows Internals" (Microsoft Press) documents > that CreateProcess starts cmd.exe to run .bat and .cmd files.
Okay, I see. So it can run a .bat if you give the extension but not implicitly via PATHEXT. In which case anything without an extension would have to be an .exe file. And of course this wouldn't explain the OP's problem anyway since they're getting output from ffmpeg. Testing the OP's actual commands out with ffmpeg I see that the problem is with the quotes. But, as you pointed out in your first post, it is the unnecessary additional quotes that are the problem rather than any missing ones. i.e. when I test it I get: # os.system output [dshow @ 02548460] Could not enumerate video devices. video=video: Input/output error # subprocess.Popen output [dshow @ 02548460] Could not enumerate video devices. video="video": Input/output error So the extra quotes used for the video and audio arguments do actually get passed through to ffmpeg causing confusion. (I don't have any video devices here so it's an error either way on this machine). Oscar _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor
