title: Webcam streaming from Mac using FFmpeg
body: <p>I want to stream my webcam from Mac using FFmpeg.</p>
  
  <p>First I checked the supported devices using <code>ffmpeg -f avfoundation -list_devices true -i ""</code></p>
  
  <p>Output:</p>
  
  <pre><code>[AVFoundation input device @ 0x7fdf1bd03000] AVFoundation video devices:
  [AVFoundation input device @ 0x7fdf1bd03000] [0] USB 2.0 Camera #2
  [AVFoundation input device @ 0x7fdf1bd03000] [1] FaceTime HD Camera
  [AVFoundation input device @ 0x7fdf1bd03000] [2] Capture screen 0
  [AVFoundation input device @ 0x7fdf1bd03000] [3] Capture screen 1
  [AVFoundation input device @ 0x7fdf1bd03000] AVFoundation audio devices:
  [AVFoundation input device @ 0x7fdf1bd03000] [0] Built-in Microphone
  </code></pre>
  
  <p>The device[0] is the webcam I want to use.</p>
  
  <hr>
  
  <p>Then I tried to capture the webcam using <code>ffmpeg -f avfoundation -i "0" out.mpg</code></p>
  
  <p>Output:</p>
  
  <pre><code>[avfoundation @ 0x7fe7f3810600] Selected framerate (29.970030) is not supported by the device
  [avfoundation @ 0x7fe7f3810600] Supported modes:
  [avfoundation @ 0x7fe7f3810600]   320x240@[120.101366 120.101366]fps
  [avfoundation @ 0x7fe7f3810600]   640x480@[120.101366 120.101366]fps
  [avfoundation @ 0x7fe7f3810600]   800x600@[60.000240 60.000240]fps
  [avfoundation @ 0x7fe7f3810600]   1024x768@[30.000030 30.000030]fps
  [avfoundation @ 0x7fe7f3810600]   1280x720@[60.000240 60.000240]fps
  [avfoundation @ 0x7fe7f3810600]   1280x1024@[30.000030 30.000030]fps
  [avfoundation @ 0x7fe7f3810600]   1920x1080@[30.000030 30.000030]fps
  [avfoundation @ 0x7fe7f3810600]   320x240@[30.000030 30.000030]fps
  [avfoundation @ 0x7fe7f3810600]   640x480@[30.000030 30.000030]fps
  [avfoundation @ 0x7fe7f3810600]   800x600@[20.000000 20.000000]fps
  [avfoundation @ 0x7fe7f3810600]   1024x768@[6.000002 6.000002]fps
  0: Input/output error
  </code></pre>
  
  <hr>
  
  <p>After that, I tried stream this webcam from my Mac using <code>ffmpeg -f avfoundation -framerate 30 -i "0" -f mpeg1video -b 200k -r 30 -vf scale=1920:1080 http://127.0.0.1:8082/</code></p>
  
  <p>Output:</p>
  
  <pre><code>[avfoundation @ 0x7f8515012800] An error occurred: The activeVideoMinFrameDuration passed is not supported by the device.  Use -activeFormat.videoSupportedFrameRateRanges to discover valid ranges.0: Input/output error
  </code></pre>
  
  <hr>
  
  <p>I cannot capture or stream this webcam. However when I used the Facetime camera instead of this webcam, everything was OK. I've been searching for this problem for a few days, but still cannot fix it. Does anyone have experience with webcam and FFmpeg on Mac?</p>