Answers.Body: <p>This can happen if the "streams do not have exactly the same length". You have to specify the range to include for the items in <code>concat.txt</code>. Try specifying the <code>duration</code> or <code>outpoint</code> or <code>in point</code>:</p>
  
  <p><a href="https://ffmpeg.org/ffmpeg-formats.html#concat" rel="nofollow noreferrer">https://ffmpeg.org/ffmpeg-formats.html#concat</a></p>
  
  <blockquote>
    <p>The duration of each file is used to adjust the timestamps of the next file: if the duration is incorrect (because it was computed using the bit-rate or because the file is truncated, for example), it can cause artifacts. The duration directive can be used to override the duration stored in each file.</p>
  </blockquote>
  
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-04T05:18:56.860Z
Answers.Text: From the Q - *in between the concatenated files* - so not within the files.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-04T11:22:03.607Z
Answers.Text: Don't use `duration` - it is meant to override the value the concat demuxer uses for calculation, not for trimming -use. `outpoint` for that.
Answers.UserDisplayName: Gyan
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2018-04-04T01:17:04.007Z
Answers.LastActivityDate: 2018-04-04T06:01:56.800Z
Answers.LastEditDate: 2018-04-04T06:01:56.800Z
Answers.UserDisplayName: aleb
Body: <p>I am using the concat demuxer in ffmpeg. I use the following command:</p>
  
  <pre><code>ffmpeg -f concat -i concat.txt -c copy out.mkv
  </code></pre>
  
  <p>and it works, except that it adds short gaps of black frames in between the concatenated files (there are three of them). How do I make it stop? If it helps, the audio is cut at those points, too.</p>
  
  <p>I know that a parameter for this exists, but I can't find the original question anywhere.</p>
  
  <p>Thanks in advance.</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2018-04-04T05:19:46.877Z
Comments.Text: Share the results of `ffprobe input` for all three files and also the content of concat.txt
Comments.UserDisplayName: Gyan
Tags: <ffmpeg><matroska>
Title: How to disable putting black frames between concatenated media with ffmpeg?
UserDisplayName: Ginkgo
ThreadText: # How to disable putting black frames between concatenated media with ffmpeg?
  
  (Asked by: username_0 on 2018-04-03)
  
  I am using the concat demuxer in ffmpeg. I use the following command:
  
  ```
  ffmpeg -f concat -i concat.txt -c copy out.mkv
  
  ```
  
  and it works, except that it adds short gaps of black frames in between the concatenated files (there are three of them). How do I make it stop? If it helps, the audio is cut at those points, too.
  
  I know that a parameter for this exists, but I can't find the original question anywhere.
  
  Thanks in advance.
  
  **Tags:** ffmpeg, matroska
  
  > **Comments:**
  > **username_1**: Share the results of `ffprobe input` for all three files and also the content of concat.txt  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_2 on 2018-04-04. Score: 1
  
  This can happen if the "streams do not have exactly the same length". You have to specify the range to include for the items in `concat.txt`. Try specifying the `duration` or `outpoint` or `in point`:
  
  <https://ffmpeg.org/ffmpeg-formats.html#concat>
  
  > The duration of each file is used to adjust the timestamps of the next file: if the duration is incorrect (because it was computed using the bit-rate or because the file is truncated, for example), it can cause artifacts. The duration directive can be used to override the duration stored in each file.
  
  > **Comments:**
  > **username_1**: From the Q - *in between the concatenated files* - so not within the files.  
  > **username_1**: Don't use `duration` - it is meant to override the value the concat demuxer uses for calculation, not for trimming -use. `outpoint` for that.  
  
  ---
  
  