libplacebo: Some shaders with multiple bindings cannot work with D3D11

mpv Information

mpv v0.41.0-dev-gdb7385799 Copyright © 2000-2026 mpv/MPlayer/mplayer2 projects
 built on May 21 2026 20:08:59
libplacebo version: v7.364.0
FFmpeg version: bbdf847
FFmpeg library versions:
   libavcodec      62.28.100
   libavdevice     62.3.100
   libavfilter     11.14.100
   libavformat     62.12.100
   libavutil       60.26.100
   libswresample   6.3.100
   libswscale      9.5.100

Other Information

- Windows version: 11
- GPU model, driver and version: RTX4080
- Source of mpv: https://nightly.link/mpv-player/mpv/workflows/build/master/mpv-v0.41.0-dev-gdb7385799-26249251048-x86_64-pc-windows-msvc.zip
- Latest known working version: n/a (at least worked servel months ago)
- Issue started after the following happened: n/a

Reproduction Steps

load the video and apply the shader as here.

Expected Behavior

No error

Actual Behavior

[e][vo/gpu-next/libplacebo] D3DCompile failed: 未指定的错误 (E_FAIL, 0x80004005)
[e][vo/gpu-next/libplacebo] error X4567: maximum cbuffer exceeded. target has 14 slots, manual bind to slot 16 failed

Log File

mpv-test.log

Sample Files

No response

I carefully read all instruction and confirm that I did the following:

• I tested and confirmed that the issue exists with the latest release version or newer.
• I provided all required information including system and mpv version.
• I produced the log file with the exact same set of files, parameters, and conditions used in "Reproduction Steps", with the addition of --log-file=output.txt.
• I produced the log file while the behaviors described in "Actual Behavior" were actively observed.
• I attached the full, untruncated log file.
• I attached the backtrace in the case of a crash.

Start by reproducing the failure in mpv with the linked Ani4Kv2_ArtCNN_C4F32_i2.glsl shader on the D3D11 path, then inspect the libplacebo shader compilation and binding logs in mpv-test.log. Done means the shader compiles and runs without the maximum-cbuffer or D3DCompile error under D3D11.