On 2 September 2013 15:19, learner404 <learner...@gmail.com> wrote:
> Hello,
>
> I can't understand why the command below works with os.system but not with
> subprocess.Popen (on windows, recording video with FFMPEG.exe)
>
> cmd=('ffmpeg -f dshow -i video="%s" -f dshow -i audio="%s" -q 5
> "%s"')%(videoinputName, audioinputName, videoFileOutput)
> os.system(cmd)
> *works*
>
> subprocess.Popen(["ffmpeg","-f","dshow","-i",'video="%s"'%videoinputName,"-f","dshow","-i",'audio="%s"'%audioinputName,"-q","5","%s"%videoFileOutput])I think you need additional quotes for the videoFileOutput part e.g. '"%s"' % videoFileOutput > *don't work* >>> [dshow @ 025984a0] Could not find video device. >>> video="QuickCam Orbit/Sphere AF": Input/output error I see that video has spaces in it. You'd think it was unnecessary to have those quotes since you've already split the command string into a list of strings. Unfortunately Windows has a fairly arcane way of handling arguments to subprocesses and Python tries to emulate that: http://docs.python.org/2/library/subprocess.html#converting-an-argument-sequence-to-a-string-on-windows > The reason I'm going with subprocess is to avoid to have the DOS window > coming in the forefront. > Any idea of what I'm doing wrong? Or any other way to hide or minimize the > DOS window? Another thing is that you shouldn't use Popen directly unless you're doing something fancy (which you're not if os.system does what you want). Use subprocess.check_call instead: subprocess.check_call(["ffmpeg","-f","dshow","-i",'video="%s"'%videoinputName,"-f","dshow","-i",'audio="%s"'%audioinputName,"-q","5",'"%s"'%videoFileOutput]) Oscar _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
