title: slices of H264 with various frame_number
body: <p>I'm decoding a H264 video bit stream. I have PPS and SPS at first, after that is I slice, P,B,SI,SP slice. I used ffmpeg to convert it into mp4 format, but the video is not correct (it's playable but can't be seen clearly). </p>
  
  <p>I think that my I-slice has been fragmented. Have you got any idea to merge them? In slices there are only frames-begin-with-0181 having frame_num from 1 to x. The other frames have non-sequency frame_num. What does that mean?</p>
  
  <p>thanks for reading.</p>