When trying to transcode: "VLC could not open the mp4a audio encoder"

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Mythical Malice
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When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Mythical Malice » 12 Sep 2016 05:09

First off, I am running Windows 10 64-bit (with Anniversary update) and VLC 64-bit 2.2.4 Weatherwax.

I am trying to transcode my video that is in a .mkv format to a .mp4 with AAC audio. Here is the original file data:
http://imgur.com/a/fF0Pc

Here are the settings I'm trying to transcode to:
http://imgur.com/a/K6smu "Destination File" in the first image should read: 'D:\Quickets\Videos\OBS Recording Vids\2016-09-10 19-18-01.mp4'

The biggest problem I am having with transcoding right now is that when I click 'Start' to start the transcoding I get an error saying: "VLC could not open the mp4a audio encoder". Image of error message here: http://imgur.com/a/vlu6T . I just let the transcode process go though so I could test it and see what would happen. I transcoded about 2 minutes of video and then stopped it so I could view the test file. The video was there but there was no audio. Here is the new file data:
http://imgur.com/a/W1siQ

So why am I getting this error message and why do I not have any audio? There is a thread from awhile ago that addresses this same issue but the solution for that problem no longer seems to apply for the current version of VLC. You can find that post here: https://forum.videolan.org/viewtopic.ph ... ba#p378214 I am unable to find the setting that they describe so I can change it. If someone has a workaround for my problem, or knows where the setting is in 2.2.4 I would appreciate the help. If you need anymore information (such as my OBS recording settings) please let me know and I will post is as soon as I can.

P.S.- I know the codec information for the original file says 'H264 - MPEG-4 AVC' with the audio already in 'MPEG AAC Audio (mp4a)' but the file is saved as a .mkv (as you can see in the address bar at the bottom of the first linked image). I guess another question is: Do I even need to transcode to a .mp4? Is it necessary, or can I just go to the original file and change the .mkv extension to .mp4? Will this break the file? I don't know that much about transcoding but I tried to find out as much as I could from the VLC forums, FAQ pages, and the Wiki pages. If I am missing something simple I apologize in advance.

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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Mythical Malice » 15 Sep 2016 00:51

Bumping to top.

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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Mythical Malice » 22 Sep 2016 00:20

Bump again. Someone please respond with a solution. This issue is getting really annoying.

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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Rémi Denis-Courmont » 27 Sep 2016 02:24

The error means that your VLC version has no MPEG 4 Audio encoder that matches your encoding settings.

(The libavcodec M4A encoder is notoriously picky about settings, and that's the only known open-source encoder.)
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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Mythical Malice » 27 Sep 2016 19:18

The libavcodec M4A encoder is notoriously picky about settings, and that's the only known open-source encoder.
So there is nothing I can do then, is what you're saying?

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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Rémi Denis-Courmont » 28 Sep 2016 02:35

I'm saying if you want to encore M4A, you need to select encoding parameters that the encoder will accept, whatever those are.
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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby Vbit-twiddler » 13 Jul 2017 07:52

Use the Convert/Stream ... selection from the File menu.

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Re: When trying to transcode: "VLC could not open the mp4a audio encoder"

Postby moviesfan20 » 13 Jul 2020 00:08

I got the same error when converting a video (I was trying to do a hyperlapse video with a FPS conversion filter). Solved with a post in a spanish forum:

Vaya a Herramientas> Preferencias> Entrada/Códecs> Códecs de video> FFmpeg Cambiando el 'Cumplimiento del estándar estricto a -2 funcionó para mí.

Worked for me.


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