user13870: I am trying to concatenate two video files using ffmpeg, and am receiving and error.
Two eliminate compatibility issues between the two videos, I am been concatenating the same video with itself, and the same error persists.
ffmpeg -f concat -safe 0 -i intro_prepped.avi intro_prepped.avi -c copy concat.avi  

And the error output I receive is....

[concat @ 0x220d420] Line 1: unknown keyword 'RIFFf�?'
  intro_prepped.avi: Invalid data found when processing input

I have tried various combinations of concat flags and have not been able to get it to work. Has anyone seen this error before?

user1871: The concat demuxer expects a text file as input.
ffmpeg -f concat -safe 0 -i list.txt -c copy concat.avi

where list.txt is
file 'intro_prepped.avi'
file 'intro_prepped.avi'


13870: <p>I am trying to concatenate two video files using ffmpeg, and am receiving and error.</p>

<p>Two eliminate compatibility issues between the two videos, I am been concatenating the same video with itself, and the same error persists.</p>

<pre><code>ffmpeg -f concat -safe 0 -i intro_prepped.avi intro_prepped.avi -c copy concat.avi  
</code></pre>

<p>And the error output I receive is....</p>

<blockquote>
  <p>[concat @ 0x220d420] Line 1: unknown keyword 'RIFFf�?'
  intro_prepped.avi: Invalid data found when processing input</p>
</blockquote>

<p>I have tried various combinations of concat flags and have not been able to get it to work. Has anyone seen this error before?</p>
 1871: <p>The concat demuxer expects a text file as input.</p>

<pre><code>ffmpeg -f concat -safe 0 -i list.txt -c copy concat.avi
</code></pre>

<p>where list.txt is</p>

<pre><code>file 'intro_prepped.avi'
file 'intro_prepped.avi'
</code></pre>
