Question

I’ve been attempting to figure this out for forever now (I’m new to programming) and I can’t figure it out.

I’m attempting to build a script that will test the file, and give me output from which I can get information like “Audio Format” that I can then put into the filename. However, I can’t even get the script to return any file info. I’ve hit a wall at inserting an input file…

So at this point I just need help getting it to spit out info based on the argvs I’ve thrown in. Hopefully I’ll be able to figure out how to parse the audio info from that.

My attempt that seems to be close:

#!/usr/bin/python
import os, sys, subprocess, shlex, re
from subprocess import call
def probe_file(filename):
    p = subprocess.Popen(['/opt/local/bin/ffprobe', '-show_format', '-pretty', '-loglevel quiet', -i filename], stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
    print filename
    print p.communicate()
[probe_file (f) for f in os.listdir('.') if not f.startswith('.')]

Answer 1

There are a few problems in your code:

1. args list to Popen has last argument as -i filename which is a syntax error use '-i '+filename instead
2. shell=True is usually not needed and is unnecessary burden.

Other than that it seems to be working, are you not seeing output after fixing #1 ?

Edit: Looks like you are having problem with ffprobe commandline, so I installed it and changes you require are:

1. My ffprobe (ffprobe 0.7.3-4:0.7.3-0ubuntu0.11.10.1) doesn’t seems to accept -i flag, input file is just passed as last argument.
2. you need to pass -loglevel and option of loglevel quiet as separate arguments i.e. [..., '-loglevel', 'quiet',..]

So after these changes here is a sample script:

#!/usr/bin/python
import os, sys, subprocess, shlex, re
from subprocess import call
def probe_file(filename):
    cmnd = ['ffprobe', '-show_format', '-pretty', '-loglevel', 'quiet', filename]
    p = subprocess.Popen(cmnd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    print filename
    out, err =  p.communicate()
    print "==========output=========="
    print out
    if err:
        print "========= error ========"
        print err

probe_file('drop.avi')

And I see the correct output:

==========output==========
[FORMAT]
filename=drop.avi
nb_streams=1
format_name=avi
format_long_name=AVI format
start_time=0:00:00.000000
duration=0:00:06.066667
size=660.000 Kibyte
bit_rate=891.217 Kbit/s
[/FORMAT]

========= error ========
ffprobe version 0.7.3-4:0.7.3-0ubuntu0.11.10.1, Copyright (c) 2007-2011 the Libav developers
  built on Jan  4 2012 16:08:51 with gcc 4.6.1
  configuration: --extra-version='4:0.7.3-0ubuntu0.11.10.1' --arch=amd64 --prefix=/usr --enable-vdpau --enable-bzlib --enable-libgsm --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-pthreads --enable-zlib --enable-libvpx --enable-runtime-cpudetect --enable-vaapi --enable-gpl --enable-postproc --enable-swscale --enable-x11grab --enable-libdc1394 --enable-shared --disable-static
  libavutil    51.  7. 0 / 51.  7. 0
  libavcodec   53.  6. 0 / 53.  6. 0
  libavformat  53.  3. 0 / 53.  3. 0
  libavdevice  53.  0. 0 / 53.  0. 0
  libavfilter   2.  4. 0 /  2.  4. 0
  libswscale    2.  0. 0 /  2.  0. 0
  libpostproc  52.  0. 0 / 52.  0. 0
Unsupported codec with id 114 for input stream 0