P: .MTS video and audio not synched on Mac OS and Adobe 24

[Patricia227709208kyp]

I am using a MAC Studio M2 machine for video editing.  Once I updated my OS to Sonoma 14.6.1 and Adobe Premiere to 24.6.1, I began having issues with importing video files.  When I import a .MTS (AVCHD) video in Premiere Pro, there is an audio drift of approximately 20 seconds.  

I did not have any issues when the OS was Ventura 13.6 or an older version of Sonoma and Abobe Premiere was 24.2.1. 

I am not sure what the issue is at this point.  

[Rach McIntire]

Hi @wxthings ,

Welcome to the Premiere Pro forums! We are glad to see you here. We need a few more details to try to help with the issue. Please see, How do I write a bug report?

Thanks for submitting your bug report. I hope we can help you soon. Sorry for the frustration! 

Thanks,
Rach

[wxthings]

Issue: No audio is detected on my MTS video (with audio) clips loaded into Premiere Pro 25, After Effects 2025 and Media Encoder 2025.

HP Z2 G9 workstation
Intel(R) Core(TM) i7-14700 2.10 GHz
64.0 GB RAM

Nvidia RTX A2000 12 GB
driver 552.34

Windows 11 Pro
version 24H2
OS build 26100.2161

HP M2 (boot) C drive
Crucial M2 D and E drives (holding video clips)

Adobe CC licensed version 6.4.0.361
Premiere 25.0
After Effects 2025
Media Encoder 2025

.MTS format clips are AVCHD H.264 4:2:0 MPEG movie, 48000 Hz compressed stereo from a Sony PXW-Z100 camera

Background: To replace a near-obsolete computer running Windows 10 Pro with Premiere 23.6.8, I recently purchased a brand new HP Z2 G9 workstation computer as configured above. Before loading any software, I did all Windows updates. I then loaded VideoLan VLC video player, Sony Catalyst Browse, Vegas DVD Architect and then my licensed Creative Cloud followed by a half dozen CC apps, including Premiere Pro 25. After transferring my Premiere Pro projects and media from my older computer to my new computer, using the same directory paths for files.

1) I open any of my projects in Premiere 25.0 and only the MTS format video clips return an error message of "MEDIA MISMATCH. The selected file does not contain audio media used by clip references in one or more sequences. These audio clip references will be deleted, and cannot be undone. Do you want to continue?"
2) If I hit OK to continue, the MTS video clips load, but with no audio.
3) If I hit Cancel, the MTS clips remain offline, but with their properties showing that they are both video and audio.
4) If I then select the offline MTS clips, go to Link, and then Locate, the clips also load without audio or an audio reference.
5) I close the project. Within Premiere, I choose the option to clean all cache files.
6) I manually go to both C:\Users\Public\Documents and to C:\Users\AlanS\AppData\Roaming\Adobe\Common and delete Adobe cache and media cache files.
7) I try opening a different project with MTS clips and get the same result where audio is not recognized.
8) I reinstalled Premiere 23.6 and get the same result where audio from MTS clips is not recognized.
9) I uninstalled all Adobe apps and Creative Cloud, cleaned the caches, reinstalled CC and the apps and got the same result where audio from MTS clips is not recognized.

As an additional test, I created a new Premiere 25.0 project.
1) I manually go to both C:\Users\Public\Documents and to C:\Users\AlanS\AppData\Roaming\Adobe\Common and delete Adobe cache and media cache files.
2) I Start Premiere while holding shift key to clear cache
3) I create new project.
4) I import .MTS clips
5) MTS clips load as video only, with no audio or audio reference

This problem occurs with old or new MTS clips in old or new Premiere Pro 25.0 or 23.6.8 projects. All other video formats such as mp4, mpg, mov, and mxf load properly with associated audio. My suspicion is there is an issue with these brand new versions of CC apps along with the brand new Windows 24H2 build. I am not able to roll back my version of Windows.

Meanwhile, on both my aging workstation running Windows 10 Pro with Premiere 23.6.9 and my backup computer running Windows 11 Home and Premiere 25.0 the MTS clips correctly load with both video and audio.

[Averdahl]

@wxthings i gave you an answer here: https://community.adobe.com/t5/premiere-pro-discussions/p-no-ac3-codec-in-windows-11-24h2-solution-i...

[defaultovzfzx2t0v0k]

Hi,

I'm currently working on a project that has been shot in AVCHD. I imported all the files using the media browser, and while most of them are fine, the spanned files get ouf of sync every time they enter a new section (they are 2G files).

Any idea on how to resolve this ? I'm running the latest stable version of Premiere Pro on a M1 Pro MacBook Pro.

Many thanks

[wxthings]

Update to the bug I'm experiencing, "No audio is detected on my MTS video (with audio) clips loaded into Premiere Pro 25, After Effects 2025 and Media Encoder 2025": After a suggestion from Community Expert Averdahl, I used Dolby Digital Plus Decoder for PC OEMs to install the AC3 codec. After doing so, Premiere 25 did detect audio on .mts clips, BUT the audio is offset by 20 frames on all existing projects and new projects. On the other hand, in Premiere 23.6.8 the audio is correctly in synch with the video.

[wxthings]

Amendment to my initial bug report: on my Dell XPS 8960 running Win 11 Home 23H2 and CC 6.4.0.361, while .mts audio is recognized, it is also off by 20 frames as it is on my HP Z2 G9 running Win 11 Pro 24H2.

[Nathan1587]

How does one roll back to the previous version? 

[mike24276214fycu]

since the update, I am having the same problem.  I am a teacher...we just got 13 new computers.  When my students ingets their clips...the lip sync is off. 

I tried on my "teachers computer" that has wored for 3 year.....tonight, my audio was out of sync on clips.  is there a setting or a box to check? 

[Averdahl]

@mike24276214fycu The only solution now is to downgrade to Premiere Pro 23.6.8. Adobe has not fixed this bug yet.

Open your Creatice Cloud app, go to Apps, click on the three dots and choose Other versions and scroll down to 23.6.8 and click on Install. Try it on one computer.

[kai_2482]

For several weeks now, my MTS files have been loading out of sync. The audio is ahead of the video (about 1 sec), and at the end, silence is added for as long as it takes for the video to finish.

The files used to work properly, but now they are suddenly no longer lip-synced.

What has changed? What can I do to fix this?

Thank you for your help!

[Michael28879975r4ud]

Just use Adobe cloud and install previous version.

[Ann Bens]

This might help

Troubleshooting linking and importing errors with MTS and MP4 files after updating to Premiere Pro C...

If not:

How do I write a bug report? - Adobe Support Community

[Theo Kooijmans]

If you install the latest Win11 version you don't have windows support voor ac3 audio anymore.

If you try to import Sony MTS clips with ac3 audio you get only video.

You can fix that by installing the dolby ac3 app from microsoft store.

Now these clips import fine in CC2023.3 and lower and ar perfect in sync.

With cc2023.6 and higher this import goes badly wrong however, audio is most of the time 13 frames off.

Steps to repro

With this link you can download the ac3 pluggin and a reference clip (MTS)

https://tkooijmans.stackstorage.com/s/SbNhQujTtewNiKcX

In CC2025 you see this, audio stops early

In CC2023.3 or lower it's perfect in sync!

[kai_2482]

Thank you kindly.

[mike24276214fycu]

Thank you.

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[MiriamVT]

Hi,

I have recently encountered an issue when updated to 25.0, when I preview some of the footage, the audio is delayed for about a second. Only clips at random are like this, the others are synced as normal. When dragged to the timeline, the audio delay is there and there a cut off about a second before the footage ends. Is this a bug from the new update? Tried looking online and haven't had much luck. This has never happened before and its quite frustrating having to sync up the audio on the specific clip I need to use, whereas the footage/audio on my camera is perfectly fine. Anyone that can help I would appreciate it. Thank you!!!!!!!!

(I'm on Windows 10 and using Premiere Pro 25.0)

[R Neil Haugen]

What is the media involved? And what is different between the clips with audio synced correctly, and those that aren't?

[jamieclarke]

Hi @MiriamVT -  We need a few more details to try to help with the issue. 

Thank you @R Neil Haugen for jumping in.  

Please let us know your answer from Neil.

We also have an open bug related to sync issues with MTS files, or AVCHD.

Sorry for the frustration.

[MiriamVT]

Hi @R Neil Haugen ,

The media involved is video clips from my Panasonic camera (HMC 150), and there's no difference between the clips, other than the audio being a second delayed. I checked on my camera and all of the footage is played normally

[MiriamVT]

Hi @jamieclarke !

I answered R Neil and my answer was:

The media involved is video clips from my Panasonic camera (HMC 150), and there's no difference between the clips, other than the audio being a second delayed. I checked on my camera and all of the footage is played normally

Any more details you need? I can provide a screen record if that helps. Thank you for the reply!

[R Neil Haugen]

It would be interesting if you checked the files in MediaInfo, a freebie utility app you can download and install easily. It's heavily used "here" to check file data.

Drag/drop a file onto the MediaInfo icon on your desktop, when it opens choose Tree View, and get a screengrab of the audio data section. Do this with a file that plays properly, and one that has the delay.

Let's see if we can see some difference in the audio metadata.

[JammyPhantom]

Hi, almost all of my cameras use .mts files and Premiere has never had an issue with them until the 2025 version. Now every file I import, the sound is offset at the end with around 30 frames of silence, so everything is out of synch and has to be manually dragged back which is mighty frustrating. I just updated my premiere this morning to see if the next version up fixes it ( v25.1.0 Build 73 ) but no joy. Has anyone else hit this annoying problem?

Premiere 25.1.0 Build 73
Windows 10 v22h2
Intel Core i7
32Gb

[filmspezialist]

I encountered this problem in PP 24.6.3 already and filed a bug report. As far as I know Adobe staff has agreed that this is a bug. Hopefully this will be fixed soon.

By the way: in my case it is not 30 frames but just 18 frames out of sync

[wxthings]

Yes, same bug for me on version 25.1 so I had to go back to version 23.6.8 for things to work correctly.

[Rach McIntire]

Updating bug status