Help get this topic noticed by sharing it on Twitter, Facebook, or email.

Sync Errors When MKV (LC-AAC) is Recoded to MPEG-4, LC-AAC or HE-AAC

As discussed in topic Nero 2014 Recode Introduces Audio/Video Sync Problems Into MPEG-4 Output Files, Nero 2014 Recode introduces sync problems when recoding a .m2ts file to MPEG-4 using LC-AAC or HE-AAC audio encoding, but not when recoding to MKV.

This topic demonstrates that severe sync problems are introduced if the in-sync
MKV (LC-AAC) is recoded to MPEG-4, LC-AAC or HE-AAC.


The test videos comprise a series of a repeated ~19 seconds video. The video shows the word START followed by the sample dolphin picture while a SoundBox voice says, "Left front, right front, center, inaudible, left rear, right rear." The sequence is repeated continuously and the words "Left front" should be heard when the word START appears.

I produced an audible demonstration placing the source MKV video on track 1 twice and the output MP4 videos on track 2 in Nero 2014 Video. I set the opacity of track 2 to 50% and deleted all but four ~19 second sections from each video. The sections are samples from the beginning, at 5 minutes, at 10 minutes, and at 15 minutes. In the video demo below, the two tracks can be heard to be increasingly out-of-sync while the video is in sync. A slight 'echo' can be noticed at the beginning; the sync error at the 15 minute point has increased to ~1.5 seconds!



I have uploaded the files used in this demonstration:
MKV Source [~1 GB]
MP4 (LC-AAC) Recode Output [~1 GB]
MP4 (HE-AAC) Recode Output [~1 GB]

A link to this topic has been sent to techsupport@nero.com.

I hope I didn't make any mistakes.
1 person has
this problem
+1
Reply