Answers.Body: <p><code>-ac 2</code> will work for any number of input channels. The example is just one use-case.</p>
  
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Answers.CreationDate: 2023-12-06T03:57:37.683Z
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Body: <p>I have a file with 7.1 audio, where each channel is in a separate mono stream. How can I convert all these mono streams to plain stereo?</p>
  <p>(The <a href="https://trac.ffmpeg.org/wiki/AudioChannelManipulation#a5.1stereo" rel="nofollow noreferrer">documentation</a> suggests to use the <code>-ac 2</code> option, but that is meant for converting 5.1 in one stream of 6 channels, not 8 separate streams)</p>
  <p>The audio I have has the streams labelled, presumably correctly, so that might help:</p>
  <pre class="lang-sh prettyprint-override"><code>$ mediainfo &quot;$in&quot; | egrep '^(Audio|Channel)'
  Audio #1
  Channel(s)                               : 1 channel
  Channel layout                           : Lt
  Audio #2
  Channel(s)                               : 1 channel
  Channel layout                           : Rt
  Audio #3
  Channel(s)                               : 1 channel
  Channel layout                           : L
  Audio #4
  Channel(s)                               : 1 channel
  Channel layout                           : R
  Audio #5
  Channel(s)                               : 1 channel
  Channel layout                           : C
  Audio #6
  Channel(s)                               : 1 channel
  Channel layout                           : LFE
  Audio #7
  Channel(s)                               : 1 channel
  Channel layout                           : Ls
  Audio #8
  Channel(s)                               : 1 channel
  Channel layout                           : Rs
  </code></pre>
  <p><strong>Update</strong>:
  In fact, the file I have is not 7.1, but Stereo + 5.1. So I already have the stereo tracks that I want, correctly labelled &quot;Lt&quot; and &quot;Rt&quot;.</p>
  <p>But there is still an aspect in the question which I would like to learn: how to convert 7.1 or 5.1 separate mono streams to a single stereo stream?</p>
  
Tags: <ffmpeg><audio><stereo>
Title: ffmpeg from 5.1 or 7.1 audio in separate mono streams to stereo
UserDisplayName: mivk
ThreadText: # ffmpeg from 5.1 or 7.1 audio in separate mono streams to stereo
  
  (Asked by: username_0 on 2023-11-17)
  
  I have a file with 7.1 audio, where each channel is in a separate mono stream. How can I convert all these mono streams to plain stereo?
  
  (The [documentation](https://trac.ffmpeg.org/wiki/AudioChannelManipulation#a5.1stereo) suggests to use the `-ac 2` option, but that is meant for converting 5.1 in one stream of 6 channels, not 8 separate streams)
  
  The audio I have has the streams labelled, presumably correctly, so that might help:
  
  ```sh
  $ mediainfo "$in" | egrep '^(Audio|Channel)'
  Audio #1
  Channel(s)                               : 1 channel
  Channel layout                           : Lt
  Audio #2
  Channel(s)                               : 1 channel
  Channel layout                           : Rt
  Audio #3
  Channel(s)                               : 1 channel
  Channel layout                           : L
  Audio #4
  Channel(s)                               : 1 channel
  Channel layout                           : R
  Audio #5
  Channel(s)                               : 1 channel
  Channel layout                           : C
  Audio #6
  Channel(s)                               : 1 channel
  Channel layout                           : LFE
  Audio #7
  Channel(s)                               : 1 channel
  Channel layout                           : Ls
  Audio #8
  Channel(s)                               : 1 channel
  Channel layout                           : Rs
  
  ```
  
  **Update**:
  In fact, the file I have is not 7.1, but Stereo + 5.1. So I already have the stereo tracks that I want, correctly labelled "Lt" and "Rt".
  
  But there is still an aspect in the question which I would like to learn: how to convert 7.1 or 5.1 separate mono streams to a single stereo stream?
  
  **Tags:** ffmpeg, audio, stereo
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2023-12-06. Score: 0
  
  `-ac 2` will work for any number of input channels. The example is just one use-case.
  
  
  ---
  
  