No method of taking a screenshot was implemented at all. vo_opengl
lacked window screenshotting, because ANGLE doesn't allow reading the
frontbuffer. There was no way to read back from a D3D11 texture either.
Implement reading image data from D3D11 textures. This is a low-quality
effort to get basic screenshots done. Eventually there will be a better
implementation: once we use AVHWFramesContext natively, the readback
implementation will be in libavcodec, and will be able to cache the
staging texture correctly. Hopefully. (For now it doesn't even have a
AVHWFramesContext for D3D11 yet. But the abstraction is more appropriate
for this purpose.)
OK, this was dumb. The file didn't have much to do with ANGLE, and the
functionality can simply be moved to d3d.c. That file contains helpers
for decoding, but can always be present (on Windows) since it doesn't
access any D3D specific libavcodec APIs. Thus it doesn't need to be
conditionally built like the actual hwaccel wrappers.
For some reason, the d3d9/dxva2/d3d11 DLLs are still optional. But we
don't need to try so hard to keep exact references. In fact, there's no
reason to unload them at all.
So load them once in a central place. For simplicity, the d3d9/d3d11
backends both load all DLLs. (They will error out only if the required
DLLs could not be loaded.)
In theory, we could just call LoadLibrary multiple times (without
calling FreeLibrary), but I'm slightly worried that this could be
detected as a "bug", or that the reference count could even have a low
static limit that could be hit soon.
In particular, this moves the depth test to common code.
Should be functionally equivalent, except that for DXVA2, the
IDirectXVideoDecoderService_GetDecoderRenderTargets API is called
more often potentially.
Some functions which expected a codec name (i.e. the name of the video
format itself) were passed a decoder name. Most "native" libavcodec
decoders have the same name as the codec, so this was never an issue.
This should mean that e.g. using "--vd=lavc:h264_mmal --hwdec=mmal"
should now actually enable native surface mode (instead of doing copy-
back).
This commit adds the d3d11va-copy hwdec mode using the ffmpeg d3d11va
api. Functions in common with dxva2 are handled in a separate decode/d3d.c
file. A future commit will rewrite decode/dxva2.c to share this code.
