Body: <p>I've used this code for merging three videos together with ffmpeg :</p>
  
  <pre><code>ffmpeg -y -f concat -safe 0 -i list.txt -c copy done.mp4
  </code></pre>
  
  <p>the list.txt contains :</p>
  
  <pre><code>file 'first.mp4'
  duration 2.5
  file 'second.mp4'
  duration 20.0
  file 'third.mp4'
  duration 1.5
  </code></pre>
  
  <p>But the output video doesn't have any sound! I want sound of each one remains on the output.</p>
  
  <p>what code should i use?</p>
  
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-01-04T21:31:03.137Z
Comments.Text: A few things that may or not help: 1. Change your container to something other than mp4, i've had sync issues with mp4 concat before. 2. Confirm there isn't multiple audio streams per ur videos, as that might require further specification. 3. try dropping the -c copy and re-encoding just to see, I'm not familiar with the "duration" bit of your command but I can see it causing issue with -c copy. 4. try command without duration specified in the .txt just to see if that's the problem. 5. Unless its related to the duration bit I'm not sure what the point of the -y is, try without it.
Comments.UserDisplayName: kite
Comments.ContentLicense: CC BY-SA 4.0
Comments.CreationDate: 2019-01-04T21:34:11.230Z
Comments.Text: 6. Confirm for certain if you haven't already there is no audio stream in the output file. Infact confirm the number of streams in general that made it over. That seems weird it wouldn't copy any audio stream at all over, i'd 'guess' it's the -y in that case.
Comments.UserDisplayName: kite
Tags: <video><ffmpeg>
Title: ffmpeg concat removing sound of videos
UserDisplayName: Ariza
ThreadText: # ffmpeg concat removing sound of videos
  
  (Asked by: username_0 on 2019-01-04)
  
  I've used this code for merging three videos together with ffmpeg :
  
  ```
  ffmpeg -y -f concat -safe 0 -i list.txt -c copy done.mp4
  
  ```
  
  the list.txt contains :
  
  ```
  file 'first.mp4'
  duration 2.5
  file 'second.mp4'
  duration 20.0
  file 'third.mp4'
  duration 1.5
  
  ```
  
  But the output video doesn't have any sound! I want sound of each one remains on the output.
  
  what code should i use?
  
  **Tags:** video, ffmpeg
  
  > **Comments:**
  > **username_1**: A few things that may or not help: 1. Change your container to something other than mp4, i've had sync issues with mp4 concat before. 2. Confirm there isn't multiple audio streams per ur videos, as that might require further specification. 3. try dropping the -c copy and re-encoding just to see, I'm not familiar with the "duration" bit of your command but I can see it causing issue with -c copy. 4. try command without duration specified in the .txt just to see if that's the problem. 5. Unless its related to the duration bit I'm not sure what the point of the -y is, try without it.  
  > **username_1**: 6. Confirm for certain if you haven't already there is no audio stream in the output file. Infact confirm the number of streams in general that made it over. That seems weird it wouldn't copy any audio stream at all over, i'd 'guess' it's the -y in that case.  
  
  ---
  
  ## 0 answers
  
  