Audio playback does not start with playhead.

TheSilentStill · Tue Feb 17, 2015 6:10 am

Hey everyone!

First the tech stuff: Macbook Pro running 10.10.2, QLC Plus 4.8.4.

I'm just getting started in QLC+, and I'm having trouble with audio playback in the 'shows' tab. I have imported an mp3 and when I go to play back it doesn't start with the play head. If the head is somewhere near the beginning of the song (first 30ish seconds) it will just start at the beginning. Otherwise if I start much later in the song it will be behind by several seconds. I searched the forum and was having trouble finding any information about this. I was also having trouble getting wav to play at all.

Any things I may be missing? Any help is seriously appreciated

Thanks!!

TheSilentStill · Tue Feb 17, 2015 8:31 pm

I've figured out the lag, it's about 36 seconds behind. Is this maybe a missing codec?

IDaninator · Tue Feb 17, 2015 9:57 pm

Hey,

this issue is related with mp3 being a problematic audioformat because it is a compressed format. You can think of it like this: What mp3 essentially does when going through a normal song is looking for 'sounds' that return. When it recognises this sound was already there it just 'takes a note' where it has to look in the cache and plays that bit. This way mp3 saves space to store the song.

The problem now is: The further you come into the song the bigger gets the difference between what mp3 has saved and what the song would be uncompressed. If you start the song it doesn't 'remind itself' and aligns to the timecode properly. This problem is not only apparent in QLC, i discovered it in LumiDMX (what I used before QLC) too.

Simple solution is to use another codec, I am using wave wich is far more reliable for these applications. On the downside it uses more diskspace.

Pretty long explanation but I didn't just want to say "use another codec".

TheSilentStill · Tue Feb 17, 2015 11:19 pm

Thanks for the detailed response!

I had tried wave initially and it didn't work.... It would make this weird sound and then not play anything. When I bounced down a new wave file at 16 bit it worked perfectly! Yay! My bit rate before must have been too high on the pervious wave file.

Another thought.... If it was possible to have multiple outputs in shows, that would be amazing. Is there any chance of that happening? I know it says that QLC isn't meant to run multi track audio (especially on windows), but it has been working great on my Mac since I fixed the file issue. If I was able to send to different channels on my 8-ch interface I could run my backing and click tracks inside QLC and not need to use Logic at all. Any chance of that feature being added?

Thanks!