Answers.Body: <p>The first line of the output you provided explains the problem:</p>
  
  <blockquote>
  <pre><code>Seems stream 0 codec frame rate differs from container frame rate: 180000.00 (180000/1) -&gt; 23.98 (24000/1001)
  </code></pre>
  </blockquote>
  
  <p>and then the last three values in the 4<sup>th</sup> line tell about it in detail:</p>
  
  <blockquote>
  <pre><code>    Stream #0.0(und): Video: h264, yuv420p, 1280x720, 23.98 tbr, 90k tbn, 180k tbc
  </code></pre>
  </blockquote>
  
  <p>which mean, in words:</p>
  
  <ul>
  <li>I guess the frame rate <code>23.98</code> fps from the input video stream.</li>
  <li>The time base in the input container is set to <code>(1/90000)</code> seconds.</li>
  <li>The time base in its video stream is set to <code>(1/180000)</code> seconds.</li>
  </ul>
  
  <p>Now, return to the the first line of your output, after the semicolon:</p>
  
  <blockquote>
  <pre><code>180000.00 (180000/1) -&gt; 23.98 (24000/1001)
  </code></pre>
  </blockquote>
  
  <p>It means: <em>Your stream's framerate is 180,000 frames per second, but I will convert it to 23.98 fps.</em></p>
  
  <p>The same is in the mentioned 4<sup>th</sup> line, in the form <code>23.98 tbr</code>. It's the FFmpeg's guessed value.</p>
  
  <p>So you are right, <em>the conversion occurs,</em> for both selected streams (video and audio one). You may see it from other lines of your output:</p>
  
  <blockquote>
  <pre><code>Stream mapping:
    Stream #0.0 -&gt; #0.0
    Stream #0.2 -&gt; #0.1
  Press [q] to stop encoding
  </code></pre>
  </blockquote>
  
  <p>because in the case of <em>copying</em> them it would be as these:</p>
  
  <blockquote>
  <pre><code>Stream mapping:
    Stream #0.0 -&gt; #0.0 (copy)
    Stream #0.2 -&gt; #0.1 (copy)
  Press [q] to stop
  </code></pre>
  </blockquote>
  
  <p><strong>The conclusion:</strong></p>
  
  <p>Your command is correct, but your input file is damaged.</p>
  
  <p>You may convince yourself about it by applying the same command to other, correct input file.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2019-06-09T08:46:27.770Z
Answers.LastActivityDate: 2019-06-09T17:11:59.327Z
Answers.LastEditDate: 2019-06-09T17:11:59.327Z
Answers.UserDisplayName: MarianD
Body: <p>I'm trying to get rid of the 1st of two audio tracks in an mp4 file. But each time I run:</p>
  
  <pre><code>ffmpeg -i test.mp4 -map 0:0 -map 0:2 -acodec copy -vcodec copy new_file.mp4
  </code></pre>
  
  <p>ffmpeg seems to reencode the file.
  The output says:</p>
  
  <pre><code>Seems stream 0 codec frame rate differs from container frame rate: 180000.00 (180000/1) -&gt; 23.98 (24000/1001)
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
    Duration: 01:01:37.25, start: 0.-83411, bitrate: 4086 kb/s
      Stream #0.0(und): Video: h264, yuv420p, 1280x720, 23.98 tbr, 90k tbn, 180k tbc
      Stream #0.1(deu): Audio: aac, 48000 Hz, 5.1, s16
      Stream #0.2(eng): Audio: aac, 48000 Hz, 5.1, s16
      Stream #0.3(und): Subtitle: text / 0x74786574
  File 'new_file2.mp4' already exists. Overwrite ? [y/N] y
  Output #0, mp4, to 'new_file2.mp4':
      Stream #0.0(und): Video: 0x0000, yuv420p, 1280x720, q=2-31, 90k tbn, 90k tbc
      Stream #0.1(eng): Audio: 0x0000, 48000 Hz, 5.1, s16
  Stream mapping:
    Stream #0.0 -&gt; #0.0
    Stream #0.2 -&gt; #0.1
  Press [q] to stop encoding
  frame=33700 fps=944 q=-1.0 size=  583098kB time=1405.53 bitrate=3398.5kbits/s 
  </code></pre>
  
  <p>And this process takes quite some time, that's why I think it reencodes instead of copying. 
  Any idea why this is? Maybe the different frame rate between container and codec?
  Thanks!</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T15:31:39.257Z
Comments.Text: Upgrade ffmpeg first. Your version is at least 7 years old.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-05-11T15:33:17.940Z
Comments.Text: Will try, I’m running on a PowerPC architecture tho.
Comments.UserDisplayName: biolightning
Tags: <ffmpeg>
Title: ffmpeg remove 1 of 2 audio tracks without video reencode
UserDisplayName: biolightning
ThreadText: # ffmpeg remove 1 of 2 audio tracks without video reencode
  
  (Asked by: username_0 on 2019-05-11)
  
  I'm trying to get rid of the 1st of two audio tracks in an mp4 file. But each time I run:
  
  ```
  ffmpeg -i test.mp4 -map 0:0 -map 0:2 -acodec copy -vcodec copy new_file.mp4
  
  ```
  
  ffmpeg seems to reencode the file.
  The output says:
  
  ```
  Seems stream 0 codec frame rate differs from container frame rate: 180000.00 (180000/1) -> 23.98 (24000/1001)
  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'test.mp4':
    Duration: 01:01:37.25, start: 0.-83411, bitrate: 4086 kb/s
      Stream #0.0(und): Video: h264, yuv420p, 1280x720, 23.98 tbr, 90k tbn, 180k tbc
      Stream #0.1(deu): Audio: aac, 48000 Hz, 5.1, s16
      Stream #0.2(eng): Audio: aac, 48000 Hz, 5.1, s16
      Stream #0.3(und): Subtitle: text / 0x74786574
  File 'new_file2.mp4' already exists. Overwrite ? [y/N] y
  Output #0, mp4, to 'new_file2.mp4':
      Stream #0.0(und): Video: 0x0000, yuv420p, 1280x720, q=2-31, 90k tbn, 90k tbc
      Stream #0.1(eng): Audio: 0x0000, 48000 Hz, 5.1, s16
  Stream mapping:
    Stream #0.0 -> #0.0
    Stream #0.2 -> #0.1
  Press [q] to stop encoding
  frame=33700 fps=944 q=-1.0 size=  583098kB time=1405.53 bitrate=3398.5kbits/s 
  
  ```
  
  And this process takes quite some time, that's why I think it reencodes instead of copying.
  Any idea why this is? Maybe the different frame rate between container and codec?
  Thanks!
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: Upgrade ffmpeg first. Your version is at least 7 years old.  
  > **username_0**: Will try, I’m running on a PowerPC architecture tho.  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2019-06-09. Score: 1
  
  The first line of the output you provided explains the problem:
  
  > ```
  > Seems stream 0 codec frame rate differs from container frame rate: 180000.00 (180000/1) -> 23.98 (24000/1001)
  >
  > ```
  
  and then the last three values in the 4th line tell about it in detail:
  
  > ```
  >     Stream #0.0(und): Video: h264, yuv420p, 1280x720, 23.98 tbr, 90k tbn, 180k tbc
  >
  > ```
  
  which mean, in words:
  
  * I guess the frame rate `23.98` fps from the input video stream.
  * The time base in the input container is set to `(1/90000)` seconds.
  * The time base in its video stream is set to `(1/180000)` seconds.
  
  Now, return to the the first line of your output, after the semicolon:
  
  > ```
  > 180000.00 (180000/1) -> 23.98 (24000/1001)
  >
  > ```
  
  It means: *Your stream's framerate is 180,000 frames per second, but I will convert it to 23.98 fps.*
  
  The same is in the mentioned 4th line, in the form `23.98 tbr`. It's the FFmpeg's guessed value.
  
  So you are right, *the conversion occurs,* for both selected streams (video and audio one). You may see it from other lines of your output:
  
  > ```
  > Stream mapping:
  >   Stream #0.0 -> #0.0
  >   Stream #0.2 -> #0.1
  > Press [q] to stop encoding
  >
  > ```
  
  because in the case of *copying* them it would be as these:
  
  > ```
  > Stream mapping:
  >   Stream #0.0 -> #0.0 (copy)
  >   Stream #0.2 -> #0.1 (copy)
  > Press [q] to stop
  >
  > ```
  
  **The conclusion:**
  
  Your command is correct, but your input file is damaged.
  
  You may convince yourself about it by applying the same command to other, correct input file.
  
  
  ---
  
  