Delaycut question about 6 chan ac3 out of sync when 2 chan is in sync

[B2K24]

I wish to use 6 chan AC3 instead of 2 chan AC3 with video I have thats in MKV
The 2 chan AC3 file is in perfect sync when remuxing with video into MKV
the 6 chan AC3 file is out of sync
How can I correct this out of sync problem?
Here is info from Delaycut

***********AC3 info thats in sync**********

====== INPUT FILE INFO ========================
File is          	ac3
Bitrate  (kbit/s) 	384
Act rate (kbit/s) 	384.000
File size (bytes)	403215360
Channels mode    	2/0: L+R
Sampling Frec    	48000
Low Frec Effects 	LFE: Not present
Duration         	02:20:00.320
Frame length (ms)	32.000000
Frames/second    	31.250000
Num of frames    	262510
Bytes per Frame  	1536.0000
Size % Framesize 	0
CRC present: 	YES
=============================================
====== TARGET FILE INFO ======================
Start Frame   	0
End Frame     	262509
Num of Frames 	262510
Duration      	02:20:00.320
NotFixedDelay 	0.0000
=============================================



**********AC3 out of sync*************
====== INPUT FILE INFO ========================
File is          	ac3
Bitrate  (kbit/s) 	448
Act rate (kbit/s) 	448.000
File size (bytes)	470747648
Channels mode    	3/2: L+C+R+SL+SR
Sampling Frec    	48000
Low Frec Effects 	LFE: Present
Duration         	02:20:06.208
Frame length (ms)	32.000000
Frames/second    	31.250000
Num of frames    	262694
Bytes per Frame  	1792.0000
Size % Framesize 	0
CRC present: 	YES

[manono]

How can I correct this out of sync problem?

Find the amount it's out of synch (5888ms?) and fix it using DelayCut before muxing into the MKV.

[B2K24]

It needed a 2 second speedup to the audio which Delaycut did rather well.
I read alot of your posts in other threads which described exactly how to use the program, many thanks.

Is it possible though, does a software exist that would modify the number of frames and duration so it could be exact?
Frame length and Frames/second are identical in both files, it's only
Duration and number of frames that don't match.
The solution you provided worked quite well, but could there be a precise way to alter the out of sync ac3 to match info of ac3 in sync?
If so how would one go about it?
Thank you again for your helpful advice.

[manono]

The solution you provided worked quite well, but could there be a precise way to alter the out of sync ac3 to match info of ac3 in sync?

No. That's why I had a question mark after my guess of 5888ms. 5.888 seconds is the difference in length between the 2 audio files but, as you found out, it doesn't necessarily follow that the delay is +/- 5888ms. It's so simple to figure out the delay, though, within a reasonable margin or error, that I don't worry about any "scientific" way to figure it out.