Body: <p>when I muxyng .mkv file and .ac3 file without converting I had next errors:</p>
  
  <ul>
  <li>[ac3]Estimating duration from bitrate, this may be inaccurate</li>
  <li>[matroska]Starting new cluster due to timestampe </li>
  <li>muxing overhead: 0.078666%</li>
  </ul>
  
  <p>ac3 error output appears before .ac3 file information
  <a href="https://i.sstatic.net/7X2p2.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/7X2p2.jpg" alt="enter image description here"></a></p>
  
  <p>mkv and muxing overhead in end of console output appears
  <a href="https://i.sstatic.net/PfGuK.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/PfGuK.jpg" alt="enter image description here"></a></p>
  
  <p>Script that i use:</p>
  
  <pre><code>ffmpeg -i input1.mkv -i input2.ac3 -map 0:v -map 1:a -map 0:a -map 0:s -c:v copy
  -c:a:1 copy -c:s copy -metadata:s:a:0 language={lang} -metadata:s:a:0 title="title1"
  -metadata:s:a:1 title="title2" output.mkv
  </code></pre>
  
  <p>I try to copy .mkv file and .ac3 separately and .mkv copying only with muxing overhead and .ac3 cppying with ac3 error(without muxing overhead).
  Could you explain what the reason of this problem, and help me with it? 
  Also <strong>after muxing in the end of output video file absent small part of audio stream from second file! How To manage with this issue?</strong></p>
  
  <p>Thanks</p>
  
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-08-19T13:53:41.267Z
Comments.Text: There aren't any errors, only info messages.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-08-19T14:22:14.890Z
Comments.Text: Yes, but there is no small part of audio stream in the end of output film
Comments.UserDisplayName: ZakZand
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-08-19T20:57:24.270Z
Comments.Text: Run `ffmpeg -i input2.ac3 -c copy input2.mp4` and then try your command with this new file.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-08-20T21:55:02.300Z
Comments.Text: Mulvya, no, I do it even with ac3 encoding, but in the end, when I copy this streams in 1 output files I have 3 minutes empty audio stream in the end of film. As I understand this issue appears because size of concrete video frame not comparable with audio stream frame... Do you have any idea what argument should I set in script to solve this issue? May be set bitrate or buffer size?
Comments.UserDisplayName: ZakZand
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-08-21T05:01:13.357Z
Comments.Text: Share the full log of the command.
Comments.UserDisplayName: Gyan
Comments.ContentLicense: CC BY-SA 3.0
Comments.CreationDate: 2017-09-10T18:04:24.413Z
Comments.Text: What part of console log you interest in?
Comments.UserDisplayName: ZakZand
Tags: <ffmpeg>
Title: [ac3]Estimating duration from bitrate, [matroska]Starting new cluster due to timestampe and muxing overhead errors when muxing .mkv and .ac3 in .mkv
UserDisplayName: ZakZand
ThreadText: # [ac3]Estimating duration from bitrate, [matroska]Starting new cluster due to timestampe and muxing overhead errors when muxing .mkv and .ac3 in .mkv
  
  (Asked by: username_0 on 2017-08-19)
  
  when I muxyng .mkv file and .ac3 file without converting I had next errors:
  
  * [ac3]Estimating duration from bitrate, this may be inaccurate
  * [matroska]Starting new cluster due to timestampe
  * muxing overhead: 0.078666%
  
  ac3 error output appears before .ac3 file information
  [![enter image description here](https://i.sstatic.net/7X2p2.jpg)](https://i.sstatic.net/7X2p2.jpg)
  
  mkv and muxing overhead in end of console output appears
  [![enter image description here](https://i.sstatic.net/PfGuK.jpg)](https://i.sstatic.net/PfGuK.jpg)
  
  Script that i use:
  
  ```
  ffmpeg -i input1.mkv -i input2.ac3 -map 0:v -map 1:a -map 0:a -map 0:s -c:v copy
  -c:a:1 copy -c:s copy -metadata:s:a:0 language={lang} -metadata:s:a:0 title="title1"
  -metadata:s:a:1 title="title2" output.mkv
  
  ```
  
  I try to copy .mkv file and .ac3 separately and .mkv copying only with muxing overhead and .ac3 cppying with ac3 error(without muxing overhead).
  Could you explain what the reason of this problem, and help me with it?
  Also **after muxing in the end of output video file absent small part of audio stream from second file! How To manage with this issue?**
  
  Thanks
  
  **Tags:** ffmpeg
  
  > **Comments:**
  > **username_1**: There aren't any errors, only info messages.  
  > **username_0**: Yes, but there is no small part of audio stream in the end of output film  
  > **username_1**: Run `ffmpeg -i input2.ac3 -c copy input2.mp4` and then try your command with this new file.  
  > **username_0**: Mulvya, no, I do it even with ac3 encoding, but in the end, when I copy this streams in 1 output files I have 3 minutes empty audio stream in the end of film. As I understand this issue appears because size of concrete video frame not comparable with audio stream frame... Do you have any idea what argument should I set in script to solve this issue? May be set bitrate or buffer size?  
  > **username_1**: Share the full log of the command.  
  > **username_0**: What part of console log you interest in?  
  
  ---
  
  ## 0 answers
  
  