title: openCV - ffmpeg H264 and Webm error
body: <p>I have ubuntu 16.04 LTS and OpenCV 3.4.0 Installed(Intel i5 and AMD graphics card), I need to create a browser supported video, which is playable in browser.</p>
  
  <p>If I'm using H264 im getting</p>
  
  <pre><code>OpenCV: FFMPEG: tag 0x34363248/'H264' is not supported with codec id 27 and format 'mp4 / MP4 (MPEG-4 Part 14)' OpenCV: FFMPEG: fallback to use tag 0x31637661/'avc1' [h264_nvenc @ 0x7f4e0407f5e0] Cannot load libcuda.so.1 Could not open codec 'h264_nvenc': Unspecified error
  </code></pre>
  
  <p>if I'm using webm VP8</p>
  
  <pre><code>OpenCV: FFMPEG: tag 0x30385056/'VP80' is not supported with codec id 139 and format 'webm / WebM'
  </code></pre>
  
  <p>if I'm using webm VP9</p>
  
  <pre><code>OpenCV: FFMPEG: tag 0x30395056/'VP90' is not supported with codec id 167 and format 'webm / WebM'
  </code></pre>
  
  <p>I'm using this code for conversion.</p>
  
  <pre><code>    fourcc = cv2.VideoWriter_fourcc(*'VP80')
      frame = cv2.imread(movements[0].file_path)
      height, width, _ = frame.shape
      event_video_name = video.file_name.split('.')[0] + '_eventvideo.webm'
      event_video = cv2.VideoWriter(path + event_video_name, fourcc, 5, (width, height))
  
      for _, image in enumerate(movements):
          image = Image.objects.get(id=image.id)
          frame = cv2.imread(image.file_path)
          event_video.write(frame)
      event_video.release()
  </code></pre>