m2ts

EricLNZ wrote on 1/8/2026, 3:59 AM

@Gen Possibly because your new install of Windows 11 doesn't have AC3 audio codec which your VP20 needs for your m2ts file. MS are no longer providing the codec with Windows.

Search the forum and you will find several threads on the problem including solutions.

Gen wrote on 1/8/2026, 6:21 AM

Thank you, EricLNZ
Installed AC3 codec drivers.
m2ts now opens in Vegas.
But Audio track is empty...

john_dennis wrote on 1/8/2026, 11:25 AM

"We" would proceed more quickly to a resolution if you would tell us what's in that m2ts wrapper by following this procedure. (FAQ) How to post MediaInfo and VEGAS Pro File Properties

Gen wrote on 1/8/2026, 11:33 PM

Gen wrote on 1/8/2026, 11:35 PM

Thanks, John
Hope this info will help.

john_dennis wrote on 1/9/2026, 12:20 AM

@Gen said: "m2ts now opens in Vegas. But Audio track is empty..."

If Vegas 20 still can't see the AC3 audio, I would question whether you were successful installing an AC3 codec.

Copy the text in this code block to NotePad and save as DolbyDigitalAudio_for_Windows_11.bat

@echo off

echo Installing Dolby Digital Plus decoder for PC OEMs...
winget install --id 9nvjqjbdkn97

echo.
echo Installing Dolby Access...
winget install --id 9n0866fs04w8

echo.
echo Opening Microsoft Store application to manually install Dolby AC-4 decoder for PC OEMs...
start ms-windows-store://pdp/?ProductId=9p7646qph1q0

pause

Run the BAT file as Administrator and answer the prompts.

Report your results.

Gen wrote on 1/9/2026, 2:00 AM

Thanks, John
AC-3 decoder installed - with special Windows applicarion,
Now VEGAS not crashed and there is sound for m2ts and MTS flles.
But for these files audiotrack is empty - pls see screenshot.

Frankly speaking, I am ready to kill Windows-11 and reinstall Windows-10 with old VEGAS, where I never had such dummy troubles.

Reyfox wrote on 1/9/2026, 7:27 AM

@Gen can you possibly supply a small sample of the problematic file to the cloud to be downloaded and tested?

RogerS wrote on 1/9/2026, 8:43 AM

Gen, did you take the code John prepared and make the bat file? You keep saying it's installed but he wants to confirm that it did it properly.

Gen wrote on 1/9/2026, 1:48 PM

Dear friends, last 12 years I worked with these "m2ts" video from my Sony camcoders and had no problem at all with VEGAS. All worked perfectly: Sony camera + Sony Notebook (Vaio from 2012) + Windows-8 + Sony Vegas-17.

This year I decided to renew the whole system - Windows-11 + Desktop with Intel 12th generation + Vegas-20. And suddenly got this problem.

I did BAT file proposed by John and downloaded Windows Media Player with AC-3 codec.
It works with m2ts files and produces sound.
Now Vegas-20 not crushes inporting m2ts video and also produces sound from it, but on maximum volume level and without usual wave picture in Audio channel.

My m2ts-video you can find here:
https://drive.google.com/file/d/1zX3ZVSa0QPHd4BEf1pmOYgIIaqoy-TlG/view?usp=drive_link

john_dennis wrote on 1/9/2026, 2:27 PM

@Gen Please share your file so others can download it.

I spend a significant portion of my time learning to do things on Windows 11 that I did in my sleep decades ago. I wrote an economics research paper on a PCjr using WordStar.

3POINT wrote on 1/9/2026, 2:38 PM

I can open/edit my old MTS (1080i50) footage in VP23 on W11, no issues with AC3 audio.

Bofus wrote on 1/9/2026, 3:11 PM

No issues opening and using M2TS (5.1 channel) media from my Sony Camera on fresh installation of windows 11. Vegas 15 through 23...

Reyfox wrote on 1/9/2026, 3:29 PM

@Gen could not access the file. Access denied....

Gen wrote on 1/9/2026, 8:36 PM

Sorry, friends. Forgot to open access. Please check.

Small remark on my operation system - Windows-11 Pro, version 25H2 (without AC-3 support).

fifonik wrote on 1/9/2026, 8:45 PM

> I did BAT file proposed by John and downloaded Windows Media Player with AC-3 codec.

WMP with AC-3 codec could play your files using in-built codec.
However, VP does not have in-built AC-3 codec and cann not use AC-3 codec that is in-built into your WMP player, but will be using a codec if it is installed system wide.

It is possible that something got wrong when you tried to install the codec using provided script and you cannot check if the codec is installed using the WPM with in-built AC-3 support.

BTW, what exactly is the WMP with AC-3 you mentioned? Is it some kind of player with codec pack? If so it was really bad idea to install it, imho.

EricLNZ wrote on 1/9/2026, 9:20 PM

@Gen Thanks for updating your link. Your 20250520145426.m2ts file opens, for me, perfectly complete with birdsong as follows:

VP21 with Win11 25H2 BUT mine is an update from an earlier Win 11 build. This build came installed on my PC and contained the Windows AC3 codec. The codec is not removed by Windows when updating to a later build. Hence I have no problem.

VP23 Build 302 Trial. No problem as Vegas introduced its own AC3 decoder in VP23 (and also later builds of VP22).

john_dennis wrote on 1/9/2026, 9:33 PM

@Gen My results with Vegas Pro 20-411 on Windows 11 Pro out-of-the box. I installed the AC3 decoder with the script that I offered.

Gen wrote on 1/9/2026, 9:34 PM

Thank you Еric. My desktop has no updates, only absolutly new installed W11 25H2. Microsoft already offically recognised - AC-3 codec is obsolete and was removed.

I will try VP23 with W11 25H2 and report back.

Gen wrote on 1/9/2026, 9:48 PM

@Gen My results with Vegas Pro 20-411 on Windows 11 Pro out-of-the box. I installed the AC3 decoder with the script that I offered.

Yes, dear John, your bat-file was installed 2 days ago.
Here you can see today's new attempt with confirmation -

Gen wrote on 1/9/2026, 10:06 PM

Hallelujah !

After new attempt of John's bat-command and restart of system finally Vegas-20 (v411) shows Audio track correctly.

Thanks to all of you and Happy New Year!

Gen wrote on 1/10/2026, 6:34 AM

Reinstalled VEGAS and found - It correctly draws waves of AudioTrack only after the second start of the Program.

One more bad news for videoeditors. This time from Sony