Increasing delay with audio track remux

[ElegantRain]

I've remuxed my Dallas Buyer's Club Blu-ray that is 01:56:40 long. I got a "scene" audio track that is in my native language but it's slightly longer at 01:56:56. So far I've been able to add and sync audio tracks with mkvtoolnix. Unfortunately this one seems to be inconsistent.

This is the same frame at different timestamps;

Introduction
webrip 00:00:46.337
remux 00:00:34.333
difference 00:00:12.004

Credits
webrip 01:53:36.893
remux 01:53:18.041
difference 00:00:18.852

Media-info of my blu-ray remux

Format : Matroska
Format version : Version 4
File size : 29.7 GiB
Duration : 1 h 56 min
Overall bit rate mode : Variable
Overall bit rate : 36.4 Mb/s

Video
Format : AVC
Format profile : High@L4.1
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 56 min
Bit rate mode : Variable
Bit rate : 30.0 Mb/s
Maximum bit rate : 35.0 Mb/s
Frame rate mode : Constant
Frame rate : 24.000 FPS
Standard : NTSC
Scan type : Progressive

Audio
Format : DTS XLL
Format/Info : Digital Theater Systems
Commercial name : DTS-HD Master Audio
Codec ID : A_DTS
Duration : 1 h 56 min
Bit rate mode : Variable
Bit rate : 3 199 kb/s
Channel(s) : 6 channels
Sampling rate : 48.0 kHz
Frame rate : 93.750 FPS (512 SPF)

Media-info of webrip

General
Format : Matroska
Format version : Version 4
File size : 2.19 GiB
Duration : 1 h 56 min
Overall bit rate : 2 684 kb/s

Video
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.1
Format settings : CABAC / 5 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 5 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 56 min
Nominal bit rate : 2 043 kb/s
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Scan type : Progressive

Audio
Format : AC-3
Format/Info : Audio Coding 3
Commercial name : Dolby Digital
Codec ID : A_AC3
Duration : 1 h 56 min
Bit rate mode : Constant
Bit rate : 256 kb/s
Channel(s) : 6 channels
Sampling rate : 48.0 kHz
Frame rate : 31.250 FPS (1536 SPF)

I want to remux the video track and keep it untouched. If the delay function isn't an option here I would like to know how to convert my audio track to the right fps.

Thank you!

[davexnet]

Yes - convert the audio. See the usage of Clever ffmpeg GUI. Source fps 23.976 target 24 adjust length only
https://forum.videohelp.com/threads/402820-NTSC-to-PAL-audio-pitch-correction-without-speedup

You'll have to nudge it a bit to sync properly, but the length should be good

[ElegantRain]

Yes - convert the audio. See the usage of Clever ffmpeg GUI. Source fps 23.976 target 24 adjust length only
https://forum.videohelp.com/threads/402820-NTSC-to-PAL-audio-pitch-correction-without-speedup

You'll have to nudge it a bit to sync properly, but the length should be good

Thank you it did work for most of the movies although I got a french track from a TV rip. The method you posted is working fine until there might be some kind of cut of a few milliseconds at a specific timestamp. Is there a visual tool to do this efficiently? I could send it in Premiere Pro but since it doesn't read the MKV container I would need to convert and I'd like not to do this. Any idea?