Answers.Body: <p>The first warning means one of the WAV inputs has no channel layout defined i.e. channel 1 is Front Left, channel 2 is Front Center..etc. <code>amerge</code> decides the channel layout of the output stream based on the input, but since that designation is missing for one of the inputs, amerge will assign a channel layout which is default for the number of channels present in the output.</p>
  
  <p>One thing you could try is rewrap all of the audio inputs i.e.</p>
  
  <pre><code>ffmpeg -i audio1.wav -c copy audio1-new.wav
  </code></pre>
  
  <hr>
  
  <p>The 2nd warning is displayed whenever VBR mode is invoked. Unless you get the error: <code>Unable to set the VBR bitrate mode</code>, you should be fine.</p>
  
Answers.ContentLicense: CC BY-SA 4.0
Answers.CreationDate: 2024-01-13T05:37:24.767Z
Answers.Text: That channel layout. Can we do it with any filter instead? I just don't want to make second file
Answers.UserDisplayName: Trương Quốc Khánh
Answers.ContentLicense: CC BY-SA 3.0
Answers.CreationDate: 2016-07-25T17:03:19.847Z
Answers.LastActivityDate: 2016-07-25T17:03:19.847Z
Answers.UserDisplayName: Gyan
Body: <p>I'm trying to merge 8 audio (.wav) files with a video (.mp4) file. I have the following command:</p>
  
  <pre><code>ffmpeg -i video.mp4 -i audio1.wav -i audio2.wav -i audio3.wav -i audio4.wav -i audio5.wav -i audio6.wav -i audio7.wav -i audio8.wav -filter_complex "[1:a][2:a]amerge=inputs=2[a0]" -filter_complex "[3:a][4:a]amerge=inputs=2[a90]" -filter_complex "[5:a][6:a]amerge=inputs=2[a180]" -filter_complex "[7:a][8:a]amerge=inputs=2[a270]" -map 0:0 -map "[a0]" -map "[a90]" -map "[a180]" -map "[a270]" -c:v copy -c:a:0 libfdk_aac -vbr:0 5 -c:a:1 libfdk_aac -vbr:1 5 -c:a:2 libfdk_aac -vbr:2 5 -c:a:3 libfdk_aac -vbr:3 5 -movflags +faststart output.mp4
  </code></pre>
  
  <p>I can successfully run the command and the output is good, but i get the following warnings displayed (3 times each):</p>
  
  <blockquote>
    <p>[Parsed_amerge_0 @ 0x7fcaca708da0] No channel layout for input 1
    [Parsed_amerge_0 @ 0x7fcaca708da0] Input channel layouts overlap:
    output layout will be determined by the number of distinct input
    channels</p>
  </blockquote>
  
  <p>And:</p>
  
  <blockquote>
    <p>[libfdk_aac @ 0x7fcacc87c800] Note, the VBR setting is unsupported and
    only works with some parameter combinations</p>
  </blockquote>
  
  <p>What do they mean and how can i "get rid of them"?</p>
  
  <p>Thanks!</p>
  
Tags: <ffmpeg>
Title: ffmpeg - warnings when i try to merge several audio files with an .mp4 file
UserDisplayName: YaronGh
ThreadText: # ffmpeg - warnings when i try to merge several audio files with an .mp4 file
  
  (Asked by: username_0 on 2016-07-25)
  
  I'm trying to merge 8 audio (.wav) files with a video (.mp4) file. I have the following command:
  
  ```
  ffmpeg -i video.mp4 -i audio1.wav -i audio2.wav -i audio3.wav -i audio4.wav -i audio5.wav -i audio6.wav -i audio7.wav -i audio8.wav -filter_complex "[1:a][2:a]amerge=inputs=2[a0]" -filter_complex "[3:a][4:a]amerge=inputs=2[a90]" -filter_complex "[5:a][6:a]amerge=inputs=2[a180]" -filter_complex "[7:a][8:a]amerge=inputs=2[a270]" -map 0:0 -map "[a0]" -map "[a90]" -map "[a180]" -map "[a270]" -c:v copy -c:a:0 libfdk_aac -vbr:0 5 -c:a:1 libfdk_aac -vbr:1 5 -c:a:2 libfdk_aac -vbr:2 5 -c:a:3 libfdk_aac -vbr:3 5 -movflags +faststart output.mp4
  
  ```
  
  I can successfully run the command and the output is good, but i get the following warnings displayed (3 times each):
  
  > [Parsed\_amerge\_0 @ 0x7fcaca708da0] No channel layout for input 1
  > [Parsed\_amerge\_0 @ 0x7fcaca708da0] Input channel layouts overlap:
  > output layout will be determined by the number of distinct input
  > channels
  
  And:
  
  > [libfdk\_aac @ 0x7fcacc87c800] Note, the VBR setting is unsupported and
  > only works with some parameter combinations
  
  What do they mean and how can i "get rid of them"?
  
  Thanks!
  
  **Tags:** ffmpeg
  
  
  ---
  
  ## 1 answers
  
  ### Answer by username_1 on 2016-07-25. Score: 0 | Accepted answer
  
  The first warning means one of the WAV inputs has no channel layout defined i.e. channel 1 is Front Left, channel 2 is Front Center..etc. `amerge` decides the channel layout of the output stream based on the input, but since that designation is missing for one of the inputs, amerge will assign a channel layout which is default for the number of channels present in the output.
  
  One thing you could try is rewrap all of the audio inputs i.e.
  
  ```
  ffmpeg -i audio1.wav -c copy audio1-new.wav
  
  ```
  
  ---
  
  The 2nd warning is displayed whenever VBR mode is invoked. Unless you get the error: `Unable to set the VBR bitrate mode`, you should be fine.
  
  > **Comments:**
  > **username_2**: That channel layout. Can we do it with any filter instead? I just don't want to make second file  
  
  ---
  
  