What controls whether Videopad see AAC 2.0 audio as stereo or mono?

topshot

I am having a bizarre issue with 16.34 or 16.38 where I can load MP4 video file with AAC 2.0 on one laptop and it will see it as having 2 channels (via Alt+Enter to view Clip Properties) but not play the audio correctly where it cuts out about every second and the seconds that do play are sped up like the chipmunks. This is even after a fresh install and project with zero effects. The audio plays as it should using MPC-HC. Unlinking the audio track has no effect.

However, on a newer laptop (and Win 10 instead of 7), Videopad only sees 1 channel for the exact same video file, and the audio does play correctly. Curiously an older version of MPC-HC also reports it as being mono when it isn't while Windows file details reports it correctly.

I could care less if it plays as stereo or mono just that it plays correctly. What settings/drivers need to be tweaked to accomplish Videopad seeing only a single channel (even though the file really has 2 channels) on the first laptop???

borate

Strange that the same VP release is giving different results on the two computers

There are no user settings for this. Is the clip solo on the timeline, or accompanied by other clips that are stereo?

Share it. Let's have a look.

Share your project. Someone will take a look and come up with a fix. The process is easy, quick and can be done privately. Just follow these steps...

Back up --- With your project on the timeline, click on MENU at the top-left. Click FILE|BACK UP PROJECT FILES TO FOLDER. Choose a folder and SELECT FOLDER.
Upload --- Use a free server - Google Drive, MS OneDrive, etc.* - to upload the saved, numbered FOLDER. Do NOT upload the individual VPJ or export file.
Get link --- Get a public link. If using Google Drive click GET SHAREABLE LINK. If necessary change "restricted" to "anyone with the link can view"
Share --- Click COPY LINK | DONE. Paste that link here, or click the folder at the top-right of this forum to message it privately to me. It won't be shared.

* Before uploading, right-click the folder, click PROPERTIES. Look at the File Size to confirm that it's not too big for the free space on the server.

If this is but a single file on the timeline, then there is no need to share the project - just upload that file.

topshot

I sent you the link to an example file. I even downloaded the older version (17.0.0) of K-Lite codec pack that was on the Win 10 laptop so MPC-HC now sees the file as being mono instead of stereo on the Win 7 laptop but it made no difference to Videopad, which I even reinstalled.

borate

On the Laptop the file has audio. On the Desktop, it has none. There's something funky about that file.

Despite being reported as two-channel in MediaInfo, it appears to actually be left-channel only. Here's the fix...

Load your file.

UNlink audio from video.

Delete the file on the audio track.

Import the file linked in the PM.

Place it below the video in Videopad.

The result will be a MONO file in both preview and export.

topshot

I'll have to try that tomorrow, but that isn't going to be a practical solution since all the videos will be the same. I still don't see why 16.34 plays it on one laptop but not the other.

borate

Similar strange behavior here, as noted, between the two machines. Doubtful that this is a Videopad issue. It shows up in viewers/players.

You can load the files into Wavepad (ignoring the prompt to open in Videopad), click the MONO button at the bottom, specify MONO at the next prompt and export as mp3.

Then follow the earlier instructions to replace existing audio in Videopad with the mp3.

There may other methods, but they don't come to mind.

topshot

I'll have to see if there is a setting on the newer camera to get around audio on only the left channel, but believe I can work around this issue using ffmpeg to manipulate the audio channels from stereo to mono.

ffmpeg -i "input.mp4" -c:v copy -ac 1 "output.mp4"

The output video then plays audio correctly in VP. I can create a batch file to process all videos in the folder to switch them to mono.