Inconsistent Playback Timing for ASF to MP4 Conversion

[oddnumber]

Hello - I used VLC (3.0.16) to convert a batch of large ASF files to MP4. However, many of the resulting MP4 files are shorter in duration than the source files. In some cases the difference is only a few seconds, but in extreme cases there may be several minutes different (~25% of the source file duration). A few examples:

Example 1: (anticipated behavior)
Source ASF - Duration 00:28:38, File Size 10.9 GB, t0 (time when event of interest begins) 00:14:16.
Output MP4 - 00:28:38, 8.9GB, t0 00:14:16.

Example 2: (clip appears to be cut off at end)
Source - 00:08:47, 3.4 GB, t0 00:05:40.
Output - 00:06:11, 1.5 GB, t0 00:05:40.

I thought I had an example where both the duration and t0 time were different between source and output, but I'm having trouble finding it. I will update my post if I find it again. I'm dealing with hundreds of files.

Any tips on troubleshooting to determine if there was an issue with the source files, user error when converting, etc.? Having the correct duration of a given event in the video is very important for my use case. I don't have admin privileges on my computer so using a nightly build as recommended in the forums may not be an option for me.

RE: Converting avi to mp4, audio is missing - https://forum.videolan.org/viewtopic.php?f=14&t=158673
RE: VLC conversion of .mp4 files working partially - https://forum.videolan.org/viewtopic.php?f=2&t=159264

Thanks!

[Lotesdelere]

There are other reports about conversion issues:
https://forum.videolan.org/viewtopic.php?f=14&t=158673
https://forum.videolan.org/viewtopic.ph ... 89#p508489

Try with a nightly build:
https://nightlies.videolan.org

Or use a dedicated video tool such as AviDemux:
http://avidemux.sourceforge.net