Distro: Linux Mint 19.1 Tessa (64 bit)
GPU: Vega 56
Driver/LLVM version: Mesa 19.1.0-devel/9.0.0
Kernel version: 5.1.0-050100-lowlatency
Proton version: 4.2-3

I'm seeing the same graphical issue, and also cut-scene videos are not played.

media_info.txt
steam-21980.log
system_info.txt

In the log I see:
227528.026:0027:0028:fixme:wmvcore:WMReader_Open (0x35ef1d0)

1464 Another game using wmvcore and the codecs are: WMV, VC-1 + WMA

installing WMP9 to add wmv playback support fixes missing cutscenes. instructions: https://github.com/ValveSoftware/Proton/issues/366#issuecomment-586774468

Call of Juarez: Bound in Blood (21980)

Issue transferred from https://github.com/ValveSoftware/Proton/issues/3751.
@FanderWasTaken posted on 2020-04-10T05:39:24:

Compatibility Report

• Name of the game with compatibility issues: Call of Juarez: Bound in Blood
• Steam AppID of the game: 21980

System Information

• GPU: Radeon RX 570
• Driver/LLVM version: 4.5 Mesa 19.2.8
• Kernel version: 5.5.15-200.fc31.x86_64
• Link to full system information report as Gist: https://gist.github.com/FanderWasTaken/d67c65b9a0ce2ed507bdb31c91d9c9eb
• Proton version: 5.0-5

I confirm:

• [x] that I haven't found an existing compatibility report for this game.
• [x] that I have checked whether there are updates for my system available.

steam-21980.log

Symptoms

• All of the audio is fine except for the voices - they are all very low quality.
• There is no intro video and no background videos in main menu.

Reproduction

Just boot up the game, load into singleplayer.

Notes

This issue with audio is also present on Windows. I know this game is from 2009, but I don't think that such low res voice lines were intentional. This issue on linux can be fixed by running this version of proton.

@FanderWasTaken commented on 2020-04-10T05:46:06:

Btw, there's also this issue #1831 but I didn't come across that.