Bad screenshot aspect ratio under specific conditions

Description

A screenshot taken of off the title screen of Saturn's game Dead or Alive (Japan), emulated through Beetle Saturn, will have a bad aspect ratio if RA's video driver is set as d3d10/d3d11/d3d12

Expected behavior

The aspect ratio scale should be respected, regardless of the video driver. When using gl video driver this issue does not happen.

Actual behavior

The titlescreen ratiot cannot possibly be correct, it squishes the image (width issue).
When the video driver is set to d3d10/11/12, I will get different resolutions and aspect ratios at different places; specific examples:

1. Title screen: 352x480 (this one is very off base, this is close to 8:11 AR)
2. Character selection: 352x240
3. Fighting arena: 704x480

RA's settings have a AR scale of 4:3, none of those screenshots seem to be at that ratio, but 2 and 3 aside, 1 (the title screen) is not right in any way.

Steps to reproduce the bug

1. Run game
2. Change video driver to d3d10/11/12
3. Take screenshot (at title screen in particular)

Bisect Results

I have no clue, all I can say is that this does not happen when using Kronos emulator; this isn't to say that the issue is the emulator, but there certainly is a causality between the two. As far as I can tell, Kronos forces the video driver back to gl or glcore anyway, but not Beetle Saturn.

I have also compared this using the same method with another title, Virtua Fighter 2 (USA); in this case the AR is closer to what would be expected, emphasis on the title screen:

1. Title screen: 704x480
2. Character selection: 352x240
3. Fighting arena: 704x480

Version/Commit

• RetroArch: 1.8.4/f425d8dc8b

Environment information

• OS: Windows 10 x64 build 18362

No source file or test is named in the report. Reproduce the Dead or Alive title-screen screenshots with Beetle Saturn under d3d10, d3d11, and d3d12, comparing them with the gl driver and the reported 4:3 setting. Done means the title screen and other reported scenes preserve the expected aspect ratio across those Direct3D drivers.