title: ffmpeg transcoding reset the start time of file
body: <p>I use a segmenter to segment my MPEG 2 Ts file into a series of media segment for HTTP live streaming</p>
  
  <p>and each segment's start time following the previous one 
  (ex:start time of segments: 00:00,00:10,00:20,00:30,...)</p>
  
  <p>(In Ubuntu)</p>
  
  <p>The Question is:</p>
  
  <p>When I use ffmpeg to transcode one of the media segment (ex 800k bps to 200k bps)</p>
  
  <p><strong>the start time of transcoded media segment will be reset to 0</strong></p>
  
  <p>ex:As I transcode the third segement,</p>
  
  <p>start time of segments changing to : 00:00,00:10,<strong>00:00</strong>,00:30,...</p>
  
  <p>It <strong>cause my player freezing</strong> once play the transcoded media segment </p>
  
  <p>Is there any solution to transcode media file with the same start time?</p>
  
  <p>I guess it's the ffmpeg reset the PTS(presentation timestamp) of segment</p>
  
  <p>But I don't know how to fix it...</p>
  
  <p><strong>here is my ffmpeg command (transcode to 250k bps)</strong></p>
  
  <p>============================</p>
  
  <pre><code>ffmpeg -y -i sample-03.ts -f mpegts -acodec libfaac -ar 48000 -ab 64k -vcodec libx264 -b 250k -flags +loop -cmp +chroma \
   -partitions +parti4x4+partp8x8+partb8x8 -subq 7 -trellis 0 -refs 0 -coder 0 -me_range 16 -keyint_min 25 \
   -sc_threshold 40 -i_qfactor 0.71 -maxrate 250k -bufsize 250k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 \
   -qmin 10 -qmax 51 -qdiff 4 -level 30 -aspect 320:240 -g 30 -async 2 sample.ts
  </code></pre>
  
  <p>============================</p>
  
  <p>Help!</p>
  
  <p>thanks</p>