title: Can't set ffmpeg header when using file for input
body: <p>I'm attempting to set headers (<a href="https://www.jokecamp.com/blog/passing-http-headers-to-ffmpeg/" rel="nofollow noreferrer">as suggested here</a>) for my ffmpeg <code>concat</code> command like so:</p>
  
  <pre><code>ffmpeg \
      -f concat \
      -safe 0 \
      -protocol_whitelist file,http,https,tcp,tls \
      -headers $'Content-Type: audio/wav\r\n' \
      -i 'inputs.txt' \
      -c 'copy' 'output.wav' \
      -v trace
  </code></pre>
  
  <p>where my input file is structured as such: </p>
  
  <pre><code>file 'https://path/to/file1'
  file 'https://path/to/file2'
  file 'https://path/to/file3'
  </code></pre>
  
  <p>However, when I run the command, ffmpeg doesn't set the headers, as seen by the output of -v:</p>
  
  <pre><code>[http @ 0x7fa133d01080] request: GET / HTTP/1.1
  User-Agent: Lavf/58.20.100
  Accept: */*
  Range: bytes=0-
  Connection: close
  Host: localhost:3001
  Icy-MetaData: 1
  </code></pre>
  
  <p>What's strange is if I set my input not through an input txt and just through  <code>-i /path/to file</code> (as seen below) it works just fine.</p>
  
  <pre><code>ffmpeg \
      -f concat \
      -safe 0 \
      -protocol_whitelist file,http,https,tcp,tls \
      -headers $'Content-Type: audio/wav\r\n' \
      -i 'https://google.com' \
      -c 'copy' 'output.wav' \
      -v trace
  </code></pre>
  
  <p>Output of -v:</p>
  
  <pre><code>[https @ 0x7fed3ac03940] request: GET / HTTP/1.1
  User-Agent: Lavf/58.20.100
  Accept: */*
  Range: bytes=0-
  Connection: close
  Host: google.com
  Icy-MetaData: 1
  Content-Type: audio/wav
  </code></pre>
  
  <p>Not sure why reading the inputs through a file would affect the headers getting sent. For now the workaround is to use a string concatenating all of the inputs (a bit messier than I'd like), but I'm curious if anyone might know why this is happening.</p>
  
  <p><strong>UPDATE</strong>: According to <a href="https://video.stackexchange.com/questions/21728/ffmpeg-concat-error">this post</a> I have to read inputs through a text file, so I'm back to square one....</p>