title: Why rtp streaming of a .avi video file fails to be received?
body: <p>In <a href="http://ffmpeg.org/trac/ffmpeg/wiki/StreamingGuide" rel="nofollow">ffmpeg streamingGuide</a>, it writes:</p>
  
  <pre><code>ffmpeg -re -f lavfi -i aevalsrc="sin(400*2*PI*t)" -ar 8000 -f mulaw -f rtp rtp://127.0.0.1:1234 &amp;
  ffplay rtp://127.0.0.1:1234
  </code></pre>
  
  <p>I want to use a real video file to replace the artificial signal.
  Then I write the below at terminal A:</p>
  
  <pre><code>ffmpeg -re -i outputFile.avi -f mulaw -f rtp rtp://127.0.0.1:1234
  </code></pre>
  
  <p>it seems it is working:
  The frame information is counting. Here are information on the terminal A at the end:</p>
  
  <pre><code>frame=  309 fps= 29 q=31.0 Lsize=     931kB time=00:00:10.30 bitrate= 740.8kbits/s     video:922kB audio:0kB subtitle:0 global headers:0kB muxing overhead 1.030813%
  </code></pre>
  
  <p>When the frame at terminal A is still counting (not finished), I type the below at terminal B:</p>
  
  <pre><code>ffplay rtp://127.0.0.1:1234
  </code></pre>
  
  <p>But it does not work:
  The error information is:</p>
  
  <pre><code>[udp @ 0x7fb370001500] bind failed: Address already in useB f=0/0   
  rtp://127.0.0.1:1234: Input/output error
  </code></pre>
  
  <p>Why?</p>
  
  <p>[Update 1] Following the instruction from Camille Goudeseune
  I used the foo.sdp<br>
  The input for the ffmpeg terminal is: </p>
  
  <blockquote>
    <p>ffmpeg -re -i out.avi -f mulaw -f rtp rtp://127.0.0.1:1235</p>
  </blockquote>
  
  <p>The terminal for ffplay is: </p>
  
  <blockquote>
    <p>ffplay -i foo.sdp</p>
  </blockquote>
  
  <p>The ffplay terminal shows a lot of error, without images.</p>
  
  <pre><code>  libpostproc    52.  2.100 / 52.  2.100
  [sdp @ 0x7fafdc0008c0] Undefined type (30)    0KB sq=    0B f=0/0   
  [sdp @ 0x7fafdc0008c0] nal size exceeds length: 25453 86 0B f=0/0   
  [sdp @ 0x7fafdc0008c0] Consumed more bytes than we got! (-25367)
  [sdp @ 0x7fafdc0008c0] nal size exceeds length: 25453 86
  [sdp @ 0x7fafdc0008c0] Consumed more bytes than we got! (-25367)
  [sdp @ 0x7fafdc0008c0] Unhandled type (27) (See RFC for implementation details
  [sdp @ 0x7fafdc0008c0] Undefined type (31)    0KB sq=    0B f=0/0   
  [sdp @ 0x7fafdc0008c0] Unhandled type (27) (See RFC for implementation details
  [sdp @ 0x7fafdc0008c0] nal size exceeds length: 62414 6130B f=0/0   
  [sdp @ 0x7fafdc0008c0] Consumed more bytes than we got! (-61801)
  [sdp @ 0x7fafdc0008c0] nal size exceeds length: 62414 613
  [sdp @ 0x7fafdc0008c0] Consumed more bytes than we got! (-61801)
  [h264 @ 0x7fafdc003020] non-existing PPS referencedq=    0B f=0/0   
  [h264 @ 0x7fafdc003020] non-existing PPS 0 referenced
  [h264 @ 0x7fafdc003020] decode_slice_header error
  [h264 @ 0x7fafdc003020] Invalid mix of idr and non-idr slices
  [sdp @ 0x7fafdc0008c0] Undefined type (31)    0KB sq=    0B f=0/0   
  [sdp @ 0x7fafdc0008c0] Unhandled type (29) (See RFC for implementation details
  [sdp @ 0x7fafdc0008c0] Unhandled type (26) (See RFC for implementation details
  [sdp @ 0x7fafdc0008c0] Unhandled type (27) (See RFC for implementation details
      Last message repeated 2 times  0KB vq=    0KB sq=    0B f=0/0   
  [sdp @ 0x7fafdc0008c0] Undefined type (31)
  [sdp @ 0x7fafdc0008c0] Unhandled type (26) (See RFC for implementation details
  [sdp @ 0x7fafdc0008c0] Unhandled type (25) (See RFC for implementation details
  [h264 @ 0x7fafdc003020] insane cropping not completely supported, this could look slightly wrong ... (left: 2, top: 2)
  [h264 @ 0x7fafdc003020] illegal aspect ratio
  [h264 @ 0x7fafdc003020] missing picture in access unit with size 84589
  [h264 @ 0x7fafdc003020] Partitioned H.264 support is incomplete
  [h264 @ 0x7fafdc003020] insane cropping not completely supported, this could look slightly wrong ... (left: 2, top: 2)
  [h264 @ 0x7fafdc003020] illegal aspect ratio
  [h264 @ 0x7fafdc003020] insane cropping not completely supported, this could look slightly wrong ... (left: 2, top: 2)
  [h264 @ 0x7fafdc003020] illegal aspect ratio
  [h264 @ 0x7fafdc003020] no frame!
  [h264 @ 0x7fafdc003020] RTP: missed 2563 packetsB sq=    0B f=0/0   
  [sdp @ 0x7fafdc0008c0] Undefined type (30)
      Last message repeated 1 times
  [sdp @ 0x7fafdc0008c0] Undefined type (31)
  </code></pre>