MP4 Library Corrupts Videos If Manipulated Quickly during Performance!

Screen Recording : Video Library Bug

Presenting a video reproduction of a reproducible glitch/bug with djay pro AI as well as djay Pro 5. Done this with MBP 2019, i7 16GB RAM with djay pro v5.0.1). External Samsung T5 2TB SSD containing 1TB of MP4 tracks mounted through Music app playlists being read by Djay Pro. In this video, I loaded a music video to deck 1 and quickly scrolled through the library back and forth, then all the tracks within that playlist stopped playing video. Their artworks stopped showing too. The actual files are NOT corrupted in finder window, AND they play well outside djay pro. The SSD drive is is good working condition. The macbook has not hanged.

The problem:
While dealing with a large playlist (or working from a master playlist containing several sub-playlists) with several hundred or thousand songs, any attempt to quickly peruse through the tracks (by rapidly scrolling, sorting by BPM or just quick searches as it happens during live performance, the following happen

  1. First the artworks disappear from view permanently
  2. Secondly, video stops displaying as the track plays
  3. In rare (not happened in later V4 updates and V5), waveform and audio disappear too. This has not happened in recent updates though).
  4. All these can only be resolved by quitting and re-launching Djay Pro - something I can’t afford in a live situation.

@NathanielAlgo @Slak_Jaw Has anybody there checked this glitch? Pretty sure it is reproducible.
Or is it just isolated to my Mac library?
Doesn’t happen on my iPad.

Hi @Armigo, I have forwarded this to the engineering team to see if they can reproduce the issue and offer any feedback. I’ll report back when I have any news. Thanks.

Hi @Armigo, does this only happen when scrolling lists of videos? If you do the same with a list of audio files does it work as expected?

I hereby upload a new video demonstrating the same, here https://youtu.be/EoNMhpqa4x8
Yes it happens when:

  1. Scrolling quickly or just looking for tracks rapidly in a fairly large list such as the master “Music” tab or in a large playlist
  2. Sometimes it happens when just sorting by BPM
    The constant is: When the list is long (several hundred of thousand tracks).

Sorry I only have MP4 as I am a video-only dj. AND my playlists are created in Music app (mac), not in djay Collections. I wish there was a way to move those playlists from “Music” to “Collections” On the iPad djay it is possible to add a playlist from “Music” tab to “Collections” tab but on a mac it not possible

Okay, thanks for the additional information.

Additional info #2:
I have manually tranfered my library off Music into “My Collection”
All 15000 video tracks imported, and currently done about 65% of the many crates and subcrates (playlists) organization, trying to mirror the setup I had in Music app. I also went ahead and unchecked “Music” tab from djay so it doesn’t have to read/load those crates anymore

3 surprises!

  1. Djay no longer glitches despite the most bizzare manipulations I perform on the master music list in My Collections (VERY GOOD). Hoooray! The only downside is:
    The entire transition process of playlists from Music to My collection is a manual job! Wishing there was a shortcut to ease it. Ipad djay at least jas the option to “Export to Playlist” whereas mac only has “Export to CSV”

  2. Loss of id3 tags were noted in a large number of tracks despite the tags being present on the actual files. I had to manually retag at least one irelevant parameter of each track and re-import for djay to re-read those tags. It used to read the same tags very well when I was still in Music app tab side, and those tags were done with the app “kid3”. Some several thousand tracks also lost bmp/key metadata, and I had to do re-analysis, which, suprisingly returned quite a number of wrong bpm values owing to this new feature of “dynamic bpm”
    Doubling of bmp was one of the issues too (not too serious).
    Will there be an update that will allow us to swtch this dynamic bpm off completely during analysis and it sticks?

  3. The option to “Remove Track from Library” is only available in the main collection master list (not in playlists!). It is also not available when you do a search of the track you wish to delete. This makes it very difficult to delete multiple tracks that have since been discarded off storage.

Thanks for the additional info @Armigo. This is very helpful. The engineering team is aware of this issue and is working towards a solution.