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.  

[Andreas23802052vbg1]

When will be a fix for <https://community.adobe.com/t5/premiere-pro-discussions/issues-with-premier-pro-not-syncing-audio-an... available? 
I have quite similar issue: 
First, new imported *.MTS-audio wasn't played in Adobe Premire Pro (v25.0.0, Build 61) due to AC-3 is not supported in Win11 24H2 anymore. 
Installing AC-3 manually (<https://www.majorgeeks.com/files/details/dolby_ac_3ac_4_installer.html>) brings audio back in Premiere Pro (v25.0.0, Build 61 and v25.1.0, Build 73) but reproducible out of lip-sync. 

Operating system: Windows 24H2 
CPU: AMD Ryzen 7 1700 Eight-Core Processor, 3.00 GHz 
GPU: NVIDIA GeForce GTX 1050 Ti 
HD/SSD: Western Digital Blue SN570 2 TByte NVMe SSD 
RAM: 16 GByte 

Camera (not a smartphone): Sony HDR-GW66 
*.MTS-File info: 

General
ID : 0 (0x0)
Vollständiger Name : C:\Eigene_Dateien\import\07.02.2025_Matthias_Rackwitz_und_Jana_Schimke_in_KW\20250207114016.m2ts
Format : BDAV
Format/Info : Blu-ray Video
Dateigröße : 1.94 GiB
Dauer : 10 min 27 s
Modus der Gesamtbitrate : Variable
Gesamte Bitrate : 26.6 Mb/s
maximale Gesamtbitrate : 28.0 Mb/s
Bildwiederholungsrate : 50.000 FPS
Aufnahmedatum : 2025-02-07 11:40:16+01:00
Kodierendes Programm : Sony HDR-GW66VE

Video
ID : 4113 (0x1011)
Menü-ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format-Profil : High@L4.2
Format-Einstellungen : CABAC / 2 Ref Frames
Format-Einstellungen für CABAC : Yes
Format-Einstellungen für RefFrames : 2 frames
Format settings, GOP : M=1, N=12
Format settings, Slice count : 4 slices per frame
Codec-ID : 27
Dauer : 10 min 27 s
Bitraten-Modus : Variable
Bitrate : 25.3 Mb/s
maximale Bitrate : 26.0 Mb/s
Breite : 1 920 pixels
Höhe : 1 080 pixels
Bildseitenverhältnis : 16:9
Bildwiederholungsrate : 50.000 FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scantyp : Progressive
Bits/(Pixel*Frame) : 0.244
Stream-Größe : 1.85 GiB (95%)
IrisFNumber : 3.400000

Audio
ID : 4352 (0x1100)
Menü-ID : 1 (0x1)
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Codec-ID : 129
Dauer : 10 min 27 s
Bitraten-Modus : Constant
Bitrate : 256 kb/s
Kanäle : 2 channels
Channel layout : L R
Samplingrate : 48.0 kHz
Bildwiederholungsrate : 31.250 FPS (1536 SPF)
Compression mode : Lossy
Stream-Größe : 19.2 MiB (1%)
Service kind : Complete Main
Dialog Normalization : -31 dB
compr : -0.28 dB
dialnorm_Average : -31 dB
dialnorm_Minimum : -31 dB
dialnorm_Maximum : -31 dB

Text
ID : 4608 (0x1200)
Menü-ID : 1 (0x1)
Format : PGS
Codec-ID : 144
Dauer : 10 min 27 s

Regards, Andreas

[Averdahl]

For now, use either the beta version 25.2 or downgrade to 23.6.8 to fix sync issues.

Installing AC-3 manually (<https://www.majorgeeks.com/files/details/dolby_ac_3ac_4_installer.html>) brings audio back in Premiere Pro (v25.0.0, Build 61 and v25.1.0, Build 73) but reproducible out of lip-sync. 

By @Andreas23802052vbg1 

[blackrosekiller]

I'm having a problem with M2TS files being out of sync by 16 frames. This only happens in Premiere Pro. 

It started with an update this past summer. I was hoping the update that just came out this week would finally include a fix. 

I have to adjust every M2TS clip. What's weird it only happens with new projects. If I import an old project with M2TS files the audio is in sync. If I import MOV from an iPhone or MP4 from my Galaxy phone into a new project it's fine. 

I see lots of other threads with people having issues with sync issues and in one of them, Adobe said a fix was coming soon. That was in November. Is there any fix for this or workaround so I don't have to adjust my clips? 

[blackrosekiller]

Just adding to the conversation. I am having the same issue with M2TS files. I assume it is because that's an AVCHD format as well. With 25.1 just having been released, any idea when 25.2 will release from beta? I can't believe it has taken Adobe this long to issue a fix.

[Kevin-Monahan]

Hi @blackrosekiller,

It's a bug that is fixed in 25.2 Beta. You can try it out there. You can also roll back 23.6.8. You can also see an Adobe Expert's reply here: https://adobe.ly/3EHlBKu. I hope the information helps.

Thanks,
Kevin

[alejandro_9769]

Hola, tenemos un problema en la universidad en la que trabajo, desde la versión 2024 hemos venido teniendo problemas con Premiere, pero con la versión 2025 es más común, en varias salas está instalado Adobe Premiere Pro versión 2025 y los estudiantes al editar, después de uno minutos se les desfasa el audio con el video, y no vuelve a cuadrarse hasta que cierran el programa y reinician el equipo, esto le sucede a más de 20 computadoras, ellos trabajan con video en .MTS y .MP4 y con los dos sucede lo mismo. 

¿Qué se debe hacer en ese caso?

[Kevin-Monahan]

Hey there, @alejandro_9769,

I think I know this issue. It's probably related to the audio portion of the A/V file. The format is older and no longer supported in Premiere Pro with the latest version of Windows 11. You can either buy the Dolby Digital plug-in or transcode the files. The FFMPEG version of the plug-in looks affordable: https://adobe.ly/3EOOAMD. Maybe you can get a site license so all your students can get back on track without having to update the video gear. The other possible solution may be an internal fix. Please run a test in Premiere Pro Beta to see if the issue has subsided. I hope the information helps the students get going again. We've all been students once!

Thanks,
Kevin

[Jose30380076lco8]

March 11, 2025

I think I found a temporary solution. I have no idea how but it works for some reason

First open media encoder -> add the clip in queue -> click play. (The output file is in mp4 and it does not have audio)

Create a new premiere file -> add the MTS clip (not the mp4 file you just got from media encoder) and your audio should now be synced.

Then export.

You must create a new premiere file for each clip with the delayed audio. 

ONLY import ONE clip at a time.

[filmspezialist]

Today I went from PP 24.6.3 to PP 25.2.3. The out-of-sync problem in m2ts files is obviousely gone. Perfect!