mp3 Audio Desync When Not Starting From Beginning

Report bugs or glitches here.
Post Reply
Bro
Posts: 3
Joined: Wed Apr 22, 2020 4:08 pm

mp3 Audio Desync When Not Starting From Beginning

Post by Bro »

Hi, I've looked around the forum and the tutorials to see if the issue I'm having has been addressed but it seems it hasn't.

When I play back my show from the beginning the timeline syncs up perfectly with the audio track (it's maybe a couple milliseconds off, but it's close enough for me) but if I play it back from anywhere but the beginning the audio starts sooner than it should.

I recorded this to demonstrate what happens, because I'm bad at explaining https://youtu.be/xULWrFJ1_Ss

In my experiments I have found that the audio starts about 1.34 seconds too soon when starting 46 seconds in, and about 0.67 seconds too soon when starting at 23 seconds, regardless of how many sets are placed inbetween those points. It happens even if I sync the sets using the 'Sync Music' function. It also happens exactly the same no matter what the bitrate or audio quality of the file.

Just now I tried using a wav file instead, and it actually has no desync. This fixes my problems, but I'll still post this topic because it's still a bug that might be good to fix.

I'm on a Windows 10 operating system, using EnVision version 1.8.11.
William
Posts: 620
Joined: Mon Jun 20, 2011 2:59 pm
Location: Kitchener, Ontario, Canada
Contact:

Re: mp3 Audio Desync When Not Starting From Beginning

Post by William »

Hi Bro,

This is actually caused by a bitrate issue. Sometimes EnVision won't start playback at the expected place if the bitrate of the audio is too high. This is due to the codec that we use to play back the music which reports unreliable time at the higher bitrates. We generally recommend using mp3s at 128kbps or lower to work correctly. Please try that and let me know if you are still having problems. When this has been reported in the past using the mp3 at 128kbps has resolved the issue.

You seem to know what you are doing surrounding bitrates, but for anyone else who finds this post there are many ways to change the bitrate of a music file you have, I have had great success using Format Factory on Windows.

Have a great day!
William Lee
-----------------
CEO
Box5 Software
https://box5software.com
Bro
Posts: 3
Joined: Wed Apr 22, 2020 4:08 pm

Re: mp3 Audio Desync When Not Starting From Beginning

Post by Bro »

I had attempted to test multiple bitrates, but looking into it the bitrates apparently weren't set to what I thought they were and the only ones I tested were 124kbps and 93kbps, both of which desynced. I converted it to exactly 128kbps using ffmpeg, and it worked perfectly. I guess I should've double checked my testing.
William
Posts: 620
Joined: Mon Jun 20, 2011 2:59 pm
Location: Kitchener, Ontario, Canada
Contact:

Re: mp3 Audio Desync When Not Starting From Beginning

Post by William »

Great! I'm glad it's working for you now! That's an interesting note about those other bitrates desyncing, both 128kbps and 96kbps have worked for me in the past.
William Lee
-----------------
CEO
Box5 Software
https://box5software.com
Post Reply