[Bug 42414] New: The Witcher 3 intro video doesn't play

https://bugs.winehq.org/show_bug.cgi?id=42414

Bug ID: 42414
           Summary: The Witcher 3 intro video doesn't play
           Product: Wine
           Version: 2.1
          Hardware: x86-64
                OS: Linux
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
      Distribution: ---

Created attachment 57236
  --> https://bugs.winehq.org/attachment.cgi?id=57236
Witcher 3 Wine log

I'm running The Witcher 3 (GOG/1.31) in Wine staging 2.1.0 with CSMT enabled.
After clicking new game and selecting a few options, the intro video doesn't
play as it should, and the game goes straight into the tutorial section (with
still broken graphics).

I tried to find anything suspicious in the log (I had to reduce the noise from
d3d and etc, using: WINEDEBUG=-dxgi,-d3d11,-d3d,-d3d_shader

See attached log for errors, but none of them look video related.

OS: Debian testing x86_64.
GPU: AMD RX 480, Mesa 13.0.3 (same happens on Mesa master).

Any suggestions how to drill down to what fails?