title: ffmpeg concat vidoes Could not find codec parameters for stream 1
body: <p>I'm trying to concat 3 vidoes, each is converted to mpg beforehand, when I run the command to concat, it gives me this error (But still produces the output with no audio)</p>
  
  <pre><code>Could not find codec parameters for stream 1 (Audio: mp2, 0 channels): unspecified frame size
  Consider increasing the value for the 'analyzeduration' and 'probesize'  options
  Input #0, mpeg, from 'concat:intermediate1.mpg|intermediate2.mpg|intermediate3.mpg':
  Duration: 00:00:25.73, start: 0.540000, bitrate: 2626 kb/s
  Stream #0:0[0x1e0]: Video: mpeg1video, yuv420p(tv), 480x414 [SAR 1:1 DAR 80:69], 104857 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc
  Stream #0:1[0x1c0]: Audio: mp2, 0 channels
  [mpeg @ 0000000002766ba0] VBV buffer size not set, using default size of 130KB
  If you want the mpeg file to be compliant to some specification
  Like DVD, VCD or others, make sure you set the correct buffer size
  Output #0, mpeg, to 'intermediate_all.mpg':
  Metadata:
  encoder  : Lavf57.50.100
  Stream #0:0: Video: mpeg1video, yuv420p(tv), 480x414 [SAR 1:1 DAR 80:69], q=2-31, 104857 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc
  Stream mapping:
  Stream #0:0 -&gt; #0:0 (copy)
  Press [q] to stop, [?] for help
  [mpeg @ 0000000002766ba0] Timestamps are unset in a packet for stream 0.  This is deprecated and will stop working in the future. Fix your code to set the   timestamps properly
  frame= 1151 fps=0.0 q=-1.0 Lsize=    7834kB time=00:00:40.81  bitrate=1572.5kbits/s speed= 346x
  video:7792kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.535638%
  </code></pre>
  
  <p>First and third videos are made by just one picture (first one 10 second and the third 5 second long) and there is no audio for them.
  the Second video which has Audio, is converted to mpg from mov by running this command :</p>
  
  <pre><code>-i test.mov -qscale:v 1 -y intermediate2.mpg
  </code></pre>
  
  <p>And I'm using this command to merge them all together:</p>
  
  <pre><code>-i concat:\"intermediate1.mpg|intermediate2.mpg|intermediate3.mpg\" -c copy -y intermediate_all.mpg
  </code></pre>
  
  <p>the final output "intermediate_all.mpg" has no audio at all. </p>
  
  <p>I also tried putting 'analyzeduration' and 'probesize' to value 100M, yet didn't work.</p>
  
  <p>Anything I'm doing wrong here?</p>