title: How to change value tbc of video with FFmpeg?
body: <p>I use <strong>FFmpeg</strong> to create video from one image with duration 10s and then cocat it with another video. The problem is the video shows glitches when play with default player of Android, but when i use <strong>MX Player</strong>, it only shows glitches in <strong>HW decoder</strong> mode, but not in <strong>SW decoder</strong> mode. I think it caused by value <strong>tbc</strong> is quite high.</p>
  
  <p>Here is command i use to create video (named <em>test3.mp4</em>) from image:
  <div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>ffmpeg -loop 1 -t 10 -framerate 25 -i a03.jpg -f lavfi -t 10 -i anullsrc -vf scale=720:1280,setsar=1:1 -video_track_timescale 90k -ac 1 -c:a aac -shortest -pix_fmt yuv420p -strict experimental -y test3.mp4</code></pre>
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  <p>Command concatenate it with video:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>ffmpeg -f concat -i file.txt -c copy -y out.mp4</code></pre>
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  <p><em>file.txt</em>:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
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  <pre class="snippet-code-html lang-html prettyprint-override"><code>file 'test1.mp4'
  file 'test3.mp4'</code></pre>
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  <p>Video <em>test1.mp4</em>: </p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test1.mp4':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2mp41
      encoder         : Lavf57.46.101
    Duration: 00:00:36.68, start: 0.000000, bitrate: 1512 kb/s
      Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 1446 kb/s, 32.32 fps, 32 tbr, 90k tbn, 7143 tbc (default)
      Metadata:
        handler_name    : VideoHandler
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s (default)
      Metadata:
        handler_name    : SoundHandler</code></pre>
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  <p>Video <em>test3.mp4</em>:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test3.mp4':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2mp41
      encoder         : Lavf57.46.101
    Duration: 00:00:10.02, start: 0.000000, bitrate: 543 kb/s
      Stream #0:0(und): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 536 kb/s, 25 fps, 25 tbr, 90k tbn, 25 tbc (default)
      Metadata:
        handler_name    : VideoHandler
      Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 1 kb/s (default)
      Metadata:
        handler_name    : SoundHandler</code></pre>
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  </p>
  
  <p>Video <em>out.mp4</em>:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'out.mp4':
    Metadata:
      major_brand     : isom
      minor_version   : 512
      compatible_brands: isomiso2mp41
      encoder         : Lavf57.46.101
    Duration: 00:00:46.73, start: 0.000000, bitrate: 1303 kb/s
      Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 720x1280 [SAR 1:1 DAR 9:16], 1240 kb/s, 30.51 fps, 32 tbr, 90k tbn, 7143 tbc (default)
      Metadata:
        handler_name    : VideoHandler
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 54 kb/s (default)
      Metadata:
        handler_name    : SoundHandler</code></pre>
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  <p>Any suggestion? Thank a lot!</p>