mpv windows下dxva2和d3d11va硬解api的差异

测试平台：五代酷睿i5 5200u核显Intel(R) HD Graphics 5500
独显NVIDIA GeForce 820M
起因是我偶然发现dxva2可以在核显上实现HEVC的硬解（Intel官网QA说只有六代skylake及以上才支持HEVC），但是感觉和平时hwdec=yes时默认的d3d11va画面有所不同。

file:///D:/image/mpv-shot0002.jpg

d3d11

上面两张核显出的，pixel format dxva2_vld和d3d11有明显差异

查询mpv手册相关关键词
vaapi and d3d11va are safe. Enabling deinterlacing (or simply their respective
post-processing filters) will possibly at least reduce color quality by converting the output to a 8
bit format.
dxva2 is not safe. It appears to always use BT.601 for forced RGB conversion, but actual
behavior depends on the GPU drivers. Some drivers appear to convert to limited range RGB,
which gives a faded appearance. In addition to driver-specific behavior, global system settings
might affect this additionally. This can give incorrect results even with completely ordinary
video sources.
All other methods, in particular the copy-back methods (like dxva2-copy etc.) should
hopefully be safe, although they can still cause random decoding issues. At the very least, they
shouldn't affect the colors of the image.

Finn 发表于 2022-1-22 18:58
上面两张核显出的，pixel format dxva2_vld和d3d11有明显差异

查询mpv手册相关关键词

软解和-copy的图就不贴了，和d3d11va完全一致

然后是n卡秀操作的时候了

没有独显直连，独显也没有视频输出，n卡驱动直接把视频相关选项隐藏了，动态范围无法调节，dxva2出来的效果是这样的

这里发个图真麻烦，还好我机智地去别的帖子里的图偷了个外链网站