DJay Pro AI for Mac video recording with audio drift

[djsteve]

I used the record function in DJay Pro AI for Mac (latest version 4.1.8) to record a five hour set with video. In reviewing the recording, there is noticeable drift in the audio, where the video increasingly leads the audio the further into the recording I view. The beginning is in sync, by the end of the five hours the audio is trailing by approximately 2.5 seconds. Examining the recorded file, it shows the following characteristics:

Duration : 5 h 0 min
Overall bit rate mode : Variable
Overall bit rate : 6 349 kb/s
Frame rate : 26.150 FPS

Video
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L3.1
Format settings : CABAC / 2 Ref Frames
Format settings, CABAC : Yes
Format settings, Reference frames : 2 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 5 h 0 min
Source duration : 5 h 0 min
Bit rate : 6 218 kb/s
Width : 1 280 pixels
Height : 720 pixels
Frame rate mode : Variable
Frame rate : 26.150 FPS
Minimum frame rate : 7.595 FPS
Maximum frame rate : 31.579 FPS

Audio
Format : AAC LC
Format/Info : Advanced Audio Codec Low Complexity
Codec ID : mp4a-40-2
Duration : 5 h 0 min
Source duration : 5 h 0 min
Bit rate mode : Variable
Bit rate : 128 kb/s
Maximum bit rate : 220 kb/s
Channel(s) : 2 channels
Channel layout : L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 SPF)

• Any ideas as to what may have caused the drift?
• Is this a known issue? Can it be fixed in later updates?
• Any suggestions for fixing the recording I have now?
• Are there any adjustments available for recording quality? I would prefer a higher resolution master for both audio and video that I can then edit as needed.

[SamJam]

It might be a good idea to include what hardware you use.

[djsteve]

In case it does matter, my report is for an issue on a 16" MacBook Pro M1Max, 64GB RAM, 4TB SSD running MacOS Ventura (13.4.1).

By demuxing the recording into separate video and audio tracks, adjusting tempo of audio, then remuxing, I found that the original audio was EXACTLY 0.01% slower than the video. I suspect a recorded set of just a few tracks wouldn’t make sync issues apparent at this small percentage, but after an hour or so it will become noticeable. My recorded set was just over 5 hours long, and thus was off by several seconds by the end, resulting in horrible lipsync.

[Alyx]

Hey @djsteve - It’s good to see you in the Community again!

First of all, apologies for the delayed reply. We tried to reproduce the issue on our end by doing an extended video recording (approx. 2 hours) but were unable to.

Has this issue happened to you more than once/have you been able to reproduce it?

The only preference to change the recording quality would be switching audio file formats between AAC and WAV. Maybe trying this would make a difference?

Looking forward to hearing back!