Audio Losing SYNC during video play

[pfelberg]

Hi.
Everytime I load any clip or video containing audio into Arena, the first thing I notice is that bpm or audio pitch is distorted - too much fast. So, everytime I need to fix that.
Yesterday, I had to play a long - like 5 minutes - clip with audio. The file was a mpeg that I converted to DXV for proper playing in Resolume.
After two minutes playing, the Audio started to lose SYNC to the video. At the end of the clip, I had like almost a 2 second delay on the Audio - horroble result. There was nothing I could do about it. I was live!
Why does this happen and what can be done to avoid it?
tks

[Basic]

did this 5 min clip play ok before hand and is it just when its been converted to dxv?

[pfelberg]

It was sent to me by a professional third party. I actually haven´t checked the original file through all it´s length and woudn´t really consider that this came from it.
I also do not believe it would be a DXV codec problem as well, although I do not use clips wth sounds very often.
As I had noticed the problem with audio files and resolume before, "the pitch thing", so I was thinking about an Avenue issue.
The video itself is an interview. There´s no way the audio would lose it´s sync during film recording.
The lack of sync is something progressive during Avenue play. It is not like a mistake of moving only the audio channel a little bit through the timeline of an editing package before encoding.

[pfelberg]

Just verifyed the original mpeg file. Audio is perfect thru the end.
Just verifyed the encoded DXV mov file out of Arena. Audio is perfect thru the end.
Opened an entire new composition in Arena with just this video. Scrolled directly to the last 1/3rd part of it.
Got the very same weird problem. No sync.

[Joris]

So you are saying you have a file which contains both audio and video, which loses sync with itself in Resolume?

That is highly irregular, and we would appreciate it if you could contact us with the file.

[pfelberg]

Yep, Joris. A single file with Audio and Video.
As weird as it may sound, that´s what was happening.

That system was a MacBook Pro running Arena 4.1.0.
I wondered that you would might request the video for examination, but it was over 3GB in size and I wouldn´t be able to send that to you. Sorry, I don´t have it anylonger.
Whenever I am able to reproduce this situation again, I promisse to send you the file.

tks

[pfelberg]

Joris,
I was able to retrieve the file again.
I am gonna try to reduce file size/lengh and still see if the problem is still occurring.
How can I upload it to you? FTP? SendSpace?

[GhostSen]

I'm having a similar problem. I shot a clip with my digital video camera, loaded it onto my computer, converted it using DXV 3 compression, imported it as a clip into Avenue and played it. I processed and re-recorded it with Avenue's clip recorder which separates the video and audio into two files (a .mov and a .wav file. Incidentally, I wish there was a way to record it as one single file). Anyway, when I imported those video and audio files into my editing software and rejoined them, on playback, they started out in sync, but progressively drifted out of sync. Is there anything that can be done about this?

[pfelberg]

My problem was related to audio encoding.
Even if sometime in your pipeline the audio file was compressed, when final exporting to Resolume the audio must have no compression at all. It must be Flat Uncompressed.
This will ensure sync inside Resolume during play.

Paulo

[GhostSen]

I'm pretty sure I did have uncompressed audio, but I just tried the whole process again and made sure that the audio was uncompressed, and I've had the same problem. Any other suggestions?

One thing I thought I could try is to record Resolume's output to an independent software recorder which records both video and audio into the same file. Can anyone recommend one which Resolume is compatible with? I have Syphon Recorder, but it doesn't input audio (except for my computer's built in microphone), only video.