WORKS (noreadonly.dll):

C:\gstreamer\1.0\x86_64\lib\gstreamer-1.0>..\..\bin\gst-launch-1.0.exe --gst-debug=d3d*:6 videotestsrc num-buffers=1 ! video/x-raw,width=637,height=480,format=I420 ! d3dvideosink
0:00:00.084014662  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dvideosink.c:168:gst_d3dvideosink_init:<GstD3DVideoSink@0000000001E0D910>
Setting pipeline to PAUSED ...
0:00:00.098496699  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dvideosink.c:439:gst_d3dvideosink_start:<d3dvideosink0> Start() called
0:00:00.105430741  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2210:d3d_class_init: D3D class init [refs:1]
0:00:00.882125961  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2573:d3d_hidden_window_thread: Direct3D hidden window handle: 0000000000170516
0:00:00.892102714  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2342:d3d_class_display_device_create:
0:00:00.895861549  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2408:d3d_class_display_device_create: Creating Direct3D device for hidden window 0000000000000000
0:00:00.915839314  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2418:d3d_class_display_device_create: Display Device format: D3DFMT_X8R8G8B8
0:00:00.920288148  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2586:d3d_hidden_window_thread: Entering Direct3D hidden window message loop
0:00:00.925699434  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2271:d3d_class_init: Hidden window message loop is running..
Pipeline is PREROLLING ...
0:00:00.930071757  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_X8B8G8R8 - FALSE
0:00:00.936392778  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_A8R8G8B8 - TRUE
0:00:00.941270353  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_A8B8G8R8 - FALSE
0:00:00.949020823  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_R8G8B8 - FALSE
0:00:00.953069840  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_R5G6B5 - TRUE
0:00:00.957778998  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_X1R5G5B5 - TRUE
0:00:00.965427764  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_YV12 - TRUE
0:00:00.969927450  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_YV12 - TRUE
0:00:00.973030344  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_NV12 - TRUE
0:00:00.979473595  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_YUY2 - TRUE
0:00:00.982807422  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_UYVY - TRUE
0:00:00.986431430  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:771:d3d_supported_caps:<d3dvideosink0> Supported Caps:
0:00:00.992201945  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> RGB15 -> D3DFMT_X1R5G5B5
0:00:00.995115427  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> RGB16 -> D3DFMT_R5G6B5
0:00:00.998079295  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> BGRA -> D3DFMT_A8R8G8B8
0:00:01.006094754  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> UYVY -> D3DFMT_UYVY
0:00:01.010074258  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> YUY2 -> D3DFMT_YUY2
0:00:01.017086210  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> NV12 -> D3DFMT_NV12
0:00:01.023765992  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> YV12 -> D3DFMT_YV12
0:00:01.029365757  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> I420 -> D3DFMT_YV12
0:00:01.032178469  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:781:d3d_supported_caps:<d3dvideosink0> BGRx -> D3DFMT_X8R8G8B8 [display]
0:00:01.038205109  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:800:d3d_supported_caps:<d3dvideosink0> Supported caps: video/x-raw, width=(int)[ 1, 2147483647 ], height=(int)[ 1, 2147483647 ], framerate=(fraction)[ 0/1, 2
147483647/1 ], format=(string){ RGB15, RGB16, BGRA, UYVY, YUY2, NV12, YV12, I420, BGRx }
0:00:01.064111076  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:285:gst_d3dvideosink_set_caps:<d3dvideosink0>
0:00:01.066971374  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:287:gst_d3dvideosink_set_caps:<d3dvideosink0> Caps: video/x-raw, format=(string)I420, width=(int)637, height=(int)480, framerate=(fraction)30/1, pixel-aspe
ct-ratio=(fraction)1/1, interlace-mode=(string)progressive
0:00:01.077765954  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:307:gst_d3dvideosink_set_caps:<d3dvideosink0> Set Caps Format: I420
0:00:01.081547183  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:321:gst_d3dvideosink_set_caps:<d3dvideosink0> video width/height: 637x480, calculated display ratio: 637/480 format: 2
0:00:01.086913682  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:332:gst_d3dvideosink_set_caps:<d3dvideosink0> keeping video height
0:00:01.091644301  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:348:gst_d3dvideosink_set_caps:<d3dvideosink0> scaling to 637x480
0:00:01.096277881  5116 00000000032EC340 DEBUG           d3dvideosink d3dvideosink.c:361:gst_d3dvideosink_set_caps:<d3dvideosink0> Selected caps: video/x-raw, format=(string)I420, width=(int)637, height=(int)480, framerate=(fraction)30/1, p
ixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive
0:00:01.108049376  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:248:gst_video_d3d_format_check:<d3dvideosink0> Checking: D3DFMT_YV12 - TRUE
0:00:01.111267036  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:833:d3d_set_render_format:<d3dvideosink0> Selected I420 -> D3DFMT_YV12
0:00:01.114669443  5116 00000000032EC540 DEBUG           d3dvideosink d3dhelpers.c:2134:d3d_internal_window_thread:<d3dvideosink0> Entering internal window thread: 00000000032EC540
0:00:01.125720615  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:2189:d3d_create_internal_window:<d3dvideosink0> Created window: 0000000000120542 (intervals: 1)
0:00:01.129779896  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:1156:d3d_prepare_window:<d3dvideosink0> No window id was set.. creating internal window
0:00:01.133270943  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:1264:d3d_init_swap_chain: Initializing Direct3D swap chain
0:00:01.136425155  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:1267:d3d_init_swap_chain: Direct3D back buffer size: 637x480
0:00:01.140640724  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:1302:d3d_init_swap_chain: Direct3D stretch rect texture filter: 0
0:00:01.144672946  5116 00000000032EC340 DEBUG           d3dvideosink d3dhelpers.c:1067:d3d_prepare_render_window:<d3dvideosink0> Prepared window for render [HWND:0000000000120542]
0:00:01.148739225  5116 00000000032EC340 LOG             d3dvideosink d3dhelpers.c:489:gst_d3dsurface_buffer_pool_new:<d3dsurfacebufferpool0> new buffer pool 0000000003360AC0
0:00:01.157926609  5116 00000000032EC340 LOG             d3dvideosink d3dhelpers.c:549:gst_d3dsurface_buffer_pool_set_config:<d3dsurfacebufferpool0> 637x480, caps video/x-raw, format=(string)I420, width=(int)637, height=(int)480, framerate=
(fraction)30/1, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive
0:00:01.170562118  5116 00000000032EC340 LOG             d3dvideosink d3dhelpers.c:489:gst_d3dsurface_buffer_pool_new:<d3dsurfacebufferpool1> new buffer pool 0000000003441EC0
0:00:01.178007944  5116 00000000032EC340 LOG             d3dvideosink d3dhelpers.c:549:gst_d3dsurface_buffer_pool_set_config:<d3dsurfacebufferpool1> 637x480, caps video/x-raw, format=(string)I420, width=(int)637, height=(int)480, framerate=
(fraction)30/1, pixel-aspect-ratio=(fraction)1/1, interlace-mode=(string)progressive
0:00:01.193763608  5116 00000000032EC340 INFO            d3dvideosink d3dhelpers.c:1831:d3d_render_buffer:<d3dvideosink0> Render 0:00:00.000000000
alloc lock 00000000047D98D8: 00000000 637 480 1024
alloc lock 000000000479C1F8: 00000000 637 480 1024
alloc lock 000000000479BFB8: 00000000 637 480 1024
map lock 000000000479BFB8: 00000002 00000000 1024
map lock 000000000479BFB8: 00000002 00000000 1024
map lock 000000000479BFB8: 00000002 00000000 1024
Pipeline is PREROLLED ...
Setting pipeline to PLAYING ...
0:00:01.232208513 New clock: GstSystemClock
 5116 00000000032EC340 INFO            d3dvideosink d3dhelpers.c:1831:d3d_render_buffer:<d3dvideosink0> Render 0:00:00.000000000
alloc lock 0000000004800C58: 00000000 637 480 1024
map lock 0000000004800C58: 00000002 00000000 1024
map lock 0000000004800C58: 00000002 00000000 1024
map lock 0000000004800C58: 00000002 00000000 1024
Got EOS from element "pipeline0".
Execution ended after 0:00:00.113615083
Setting pipeline to PAUSED ...
Setting pipeline to READY ...
Setting pipeline to NULL ...
0:00:01.395970950  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dvideosink.c:449:gst_d3dvideosink_stop:<d3dvideosink0> Stop() called
0:00:01.425402954  5116 00000000032EF8A0 LOG             d3dvideosink d3dhelpers.c:499:gst_d3dsurface_buffer_pool_finalize:<d3dsurfacebufferpool0> finalize buffer pool 0000000003360AC0
0:00:01.438960795  5116 00000000032EF8A0 LOG             d3dvideosink d3dhelpers.c:499:gst_d3dsurface_buffer_pool_finalize:<d3dsurfacebufferpool1> finalize buffer pool 0000000003441EC0
0:00:01.450516286  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:1094:d3d_set_window_handle:<d3dvideosink0> Unsetting window [HWND:0000000000120542]
0:00:01.450560607  5116 00000000032EC540 DEBUG           d3dvideosink d3dhelpers.c:2159:d3d_internal_window_thread:<d3dvideosink0> Exiting internal window thread: 00000000032EC540
0:00:01.461557661  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:978:d3d_window_wndproc_unset:<d3dvideosink0>
0:00:01.491789765  5116 00000000032EF8A0 WARN            d3dvideosink d3dhelpers.c:989:d3d_window_wndproc_unset:<d3dvideosink0> D3D window proc is not set on current window
0:00:01.503180571  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:1330:d3d_release_swap_chain:<d3dvideosink0> Releasing Direct3D swap chain
0:00:01.513628986  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:1342:d3d_release_swap_chain:<d3dvideosink0> D3D swapchain released. Ref count: 0
0:00:01.526163259  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:1348:d3d_release_swap_chain:<d3dvideosink0> D3D surface released. Ref count: 0
0:00:01.538431143  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2295:d3d_class_destroy: D3D class destroy [refs:0]
0:00:01.550169048  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2305:d3d_class_destroy: Shutting down window proc thread, waiting to join..
0:00:01.560182190  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2603:d3d_hidden_window_thread: Leaving Direct3D hidden window message loop
0:00:01.587615577  5116 00000000032EC300 DEBUG           d3dvideosink d3dhelpers.c:2440:d3d_class_display_device_destroy: Direct3D device [adapter:0] released. Reference count: 0
0:00:01.595070267  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2308:d3d_class_destroy: Joined..
0:00:01.598881354  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dhelpers.c:2316:d3d_class_destroy: Direct3D object released. Reference count: 0
Freeing pipeline ...
0:00:01.625199267  5116 00000000032EF8A0 DEBUG           d3dvideosink d3dvideosink.c:187:gst_d3dvideosink_finalize:<d3dvideosink0>