Author Topic: How to enable sound output for MP4 video?  (Read 1049 times)

pstein

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How to enable sound output for MP4 video?
« on: October 31, 2019, 10:47:10 AM »
When I play videos v´with some external videoplayers like VLC then I can hear the sound/audio track.

When I load the same *.mp4 video into Avidemux v2.7.5 on Win7 64bit and click on the "Play" control then the video is playing but WITHOUT sound.

Why?

Do I have to enable somehow audio output?

video codec is MPEG-4 Base media AVC

audio codec is AAC LC

Peter

eumagga0x2a

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Re: How to enable sound output for MP4 video?
« Reply #1 on: October 31, 2019, 11:13:15 AM »
This is a frequently recurring question. Please check in the Preferences --> Audio --> AudioDevice that you have chosen the "Win32" audio output, not the "Dummy" one.

pstein

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Re: How to enable sound output for MP4 video?
« Reply #2 on: October 31, 2019, 01:42:11 PM »
It works
Thank you

dosdan

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Re: How to enable sound output for MP4 video?
« Reply #3 on: October 31, 2019, 09:42:59 PM »
This is a frequently recurring question. Please check in the Preferences --> Audio --> AudioDevice that you have chosen the "Win32" audio output, not the "Dummy" one.

Under what circumstances was it was envisioned that users would use the "dummy" audio device?  If it is only there for temporary troubleshooting, perhaps a test could be performed at startup, and if "dummy" is currently selected, a warning message should be displayed.

Dan.
« Last Edit: October 31, 2019, 09:45:28 PM by dosdan »

eumagga0x2a

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Re: How to enable sound output for MP4 video?
« Reply #4 on: November 01, 2019, 08:10:09 AM »
Under what circumstances was it was envisioned that users would use the "dummy" audio device?

I can only guess, but what if the real one reproducibly or frequently crashes? A null output would allow to edit video without disabling the audio track. I mean that the reason may be very valid.

With old configuration wiped out, current and sufficiently old Avidemux versions will never select the dummy audio output by default. There was a bug with 2.7.2 and 2.7.3 VC++ builds however as the define used to enable code setting the device to Win32 was wrong for VC++ (worked only for MinGW), fixed by [main] Use the right define to fix audio device set to dummy upon a fresh install on Windows with VC++ builds. The issue never existed in MinGW builds.

So the only easy way to end up with the dummy output is to launch Avidemux VC++ 2.7.2 or 2.7.3 after user profile data was cleared.