title: avconv with subprocess
body: <p>It's seems like I never really manage to wrap my head around subprocess. This commandline works in bash</p>
  
  <pre><code>avconv -i "concat:/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment0.ts|/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment1.ts" -vcodec copy -acodec copy /tmp/test1.ts
  </code></pre>
  
  <p>Bu if I try this:</p>
  
  <pre><code>cmdline = ['avconv', '-i "concat:/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment0.ts|/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment1.ts"', '-vcodec copy', '-acodec copy', '/tmp/test1.ts']
  subprocess.call(cmdline)
  </code></pre>
  
  <p>It exit avconv with the following error:</p>
  
  <pre><code>avconv version 0.8.3-4:0.8.3-0ubuntu0.12.04.1, Copyright (c) 2000-2012 the Libav developers
    built on Jun 12 2012 16:52:09 with gcc 4.6.3
  Unrecognized option 'i "concat:/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment0.ts|/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment1.ts"'
  Failed to set value '-vcodec copy' for option 'i "concat:/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment0.ts|/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment1.ts"'
  1
  </code></pre>
  
  <p>I've tried some variants (including shell=True) but I can't figure out the problem.</p>
  
  <h2>Update</h2>
  
  <p>Cjb made an answer that really worked. But my real code is more complicated. I believe it's hard to get something out of it. But I throw it in here just in case there is an obvoius problem that I missed.</p>
  
  <pre><code>def run_avconv(output_dir, fnames):
      full_fnames = [os.path.join(output_dir, fname.replace('\n', ''))
                     for fname in fnames]
      concatted_files = '|'.join(full_fnames)
      cmd_line = [AVCONV_CMD,
                  '-i',
                  '"concat:' + concatted_files + '"',
                  '-vcodec',
                  'copy',
                  '-acodec',
                  'copy',
                  os.path.join(output_dir, 'out.ts')]
      subprocess.Popen(cmd_line)
  </code></pre>
  
  <p>the full_fnames variable is:</p>
  
  <pre><code>['/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment0.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment1.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment2.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment3.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment4.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment5.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment6.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment7.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment8.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment9.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment10.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment11.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment12.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment13.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment14.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment15.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment16.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment17.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment18.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment19.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment20.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment21.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment22.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment23.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment24.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment25.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment26.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment27.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment28.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment29.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment30.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment31.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment32.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment33.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment34.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment35.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment36.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment37.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment38.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment39.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment40.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment41.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment42.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment43.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment44.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment45.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment46.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment47.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment48.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment49.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment50.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment51.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment52.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment53.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment54.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment55.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment56.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment57.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment58.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment59.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment60.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment61.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment62.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment63.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment64.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment65.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment66.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment67.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment68.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment69.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment70.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment71.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment72.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment73.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment74.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment75.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment76.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment77.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment78.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment79.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment80.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment81.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment82.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment83.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment84.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment85.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment86.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment87.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment88.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment89.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment90.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment91.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment92.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment93.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment94.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment95.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment96.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment97.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment98.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment99.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment100.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment101.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment102.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment103.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment104.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment105.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment106.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment107.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment108.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment109.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment110.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment111.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment112.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment113.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment114.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment115.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment116.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment117.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment118.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment119.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment120.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment121.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment122.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment123.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment124.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment125.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment126.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment127.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment128.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment129.ts',
   '/tmp/BABAR_AND_THE_A-011A-hts-a-v1-cc3651d01841d748_Layer6/6148_Period1/segment130.ts']
  </code></pre>