vo_opengl: remove dxva2 dummy hwdec backend

This was a hack to let libmpv API users pass a d3d device to mpv. It's
not needed anymore for 2 reasons:

1. ANGLE does not have this problem
2. Even native GL via nVidia (where this failed) seems to not require
   this anymore

DOCS/interface-changes.rst

@@ -19,6 +19,9 @@ Interface changes
 
 ::
 
+ --- mpv 0.25.0 ---
+    - remove opengl-cb dxva2 dummy hwdec interop
+      (see git "vo_opengl: remove dxva2 dummy hwdec backend")
  --- mpv 0.24.0 ---
     - deprecate --hwdec-api and replace it with --opengl-hwdec-interop.
       The new option accepts both --hwdec values, as well as named backends.

libmpv/opengl_cb.h

@@ -174,26 +174,9 @@ extern "C" {
  * Windowing system interop on MS win32
  * ------------------------------------
  *
- * Warning: the following is only required if native OpenGL instead of ANGLE
- *          is used. ANGLE is recommended, because it also allows direct
- *          hardware decoding interop without further setup by the libmpv
- *          API user, while the same with native OpenGL is either very hard
- *          to do (via GL/DX interop with D3D9), or not implemented.
- *
- * If OpenGL switches to fullscreen, most players give it access GPU access,
- * which means DXVA2 hardware decoding in mpv won't work. This can be worked
- * around by giving mpv access to Direct3D device, which it will then use to
- * create a decoder. The device can be either the real device used for display,
- * or a "blank" device created before switching to fullscreen.
- *
- * You can provide glMPGetNativeDisplay as described in the previous section.
- * If it is called with name set to "IDirect3DDevice9", it should return a
- * IDirect3DDevice9 pointer (or NULL if not available). libmpv will release
- * this interface when it is done with it.
- *
- * In previous libmpv releases, this used "GL_MP_D3D_interfaces" and
- * "glMPGetD3DInterface". This is deprecated; use glMPGetNativeDisplay instead
- * (the semantics are 100% compatible).
+ * You should use ANGLE, and make sure your application and libmpv are linked
+ * to the same ANGLE DLLs. libmpv will pick the device context (needed for
+ * hardware decoding) from the current ANGLE EGL context.
  *
  * Windowing system interop on RPI
  * -------------------------------

video/out/opengl/hwdec.c

@@ -59,7 +59,6 @@ static const struct gl_hwdec_driver *const mpgl_hwdec_drivers[] = {
 #if HAVE_GL_DXINTEROP
     &gl_hwdec_dxva2gldx,
 #endif
-    &gl_hwdec_dxva2,
 #endif
 #if HAVE_CUDA_HWACCEL
     &gl_hwdec_cuda,

video/out/opengl/hwdec_dxva2.c

@@ -1,68 +0,0 @@
-#include <d3d9.h>
-
-#include "common/common.h"
-
-#include "hwdec.h"
-#include "utils.h"
-#include "video/hwdec.h"
-
-// This does not provide real (zero-copy) interop - it merely exists for
-// making sure the same D3D device is used for decoding and display, which
-// may help with OpenGL fullscreen mode.
-
-struct priv {
-    struct mp_hwdec_ctx hwctx;
-};
-
-static void destroy(struct gl_hwdec *hw)
-{
-    struct priv *p = hw->priv;
-    hwdec_devices_remove(hw->devs, &p->hwctx);
-    if (p->hwctx.ctx)
-        IDirect3DDevice9_Release((IDirect3DDevice9 *)p->hwctx.ctx);
-}
-
-static int create(struct gl_hwdec *hw)
-{
-    GL *gl = hw->gl;
-    if (!gl->MPGetNativeDisplay)
-        return -1;
-
-    struct priv *p = talloc_zero(hw, struct priv);
-    hw->priv = p;
-
-    IDirect3DDevice9 *d3d = gl->MPGetNativeDisplay("IDirect3DDevice9");
-    if (!d3d)
-        return -1;
-
-    MP_VERBOSE(hw, "Using libmpv supplied device %p.\n", d3d);
-
-    p->hwctx = (struct mp_hwdec_ctx){
-        .type = HWDEC_DXVA2_COPY,
-        .driver_name = hw->driver->name,
-        .ctx = d3d,
-    };
-    hwdec_devices_add(hw->devs, &p->hwctx);
-    return 0;
-}
-
-static int reinit(struct gl_hwdec *hw, struct mp_image_params *params)
-{
-    return -1;
-}
-
-static int map_frame(struct gl_hwdec *hw, struct mp_image *hw_image,
-                     struct gl_hwdec_frame *out_frame)
-{
-    return -1;
-}
-
-const struct gl_hwdec_driver gl_hwdec_dxva2 = {
-    .name = "dxva2-dummy",
-    .api = HWDEC_DXVA2_COPY,
-    .imgfmt = -1,
-    .create = create,
-    .reinit = reinit,
-    .map_frame = map_frame,
-    .destroy = destroy,
-};

wscript_build.py

@@ -366,7 +366,6 @@ def build(ctx):
         ( "video/out/opengl/hwdec_cuda.c",       "cuda-hwaccel" ),
         ( "video/out/opengl/hwdec_d3d11egl.c",   "egl-angle" ),
         ( "video/out/opengl/hwdec_d3d11eglrgb.c","egl-angle" ),
-        ( "video/out/opengl/hwdec_dxva2.c",      "gl-win32" ),
         ( "video/out/opengl/hwdec_dxva2gldx.c",  "gl-dxinterop" ),
         ( "video/out/opengl/hwdec_dxva2egl.c",   "egl-angle" ),
         ( "video/out/opengl/hwdec_osx.c",        "videotoolbox-gl" ),