[vlc-commits] [Git][videolan/vlc][master] d3d11: remove Query based rendering wait

[Steve Lhomme]

Steve Lhomme pushed to branch master at VideoLAN / VLC


Commits:
141e07e1 by Steve Lhomme at 2021-05-25T06:35:49+00:00
d3d11: remove Query based rendering wait

It is imprecise and on seek it may wait a lot of time as, while it's waiting,
the decoder threads will flood new frames, delaying that much longer until the
ID3D11DeviceContext is finished doing things. This workaround did more harm
than good.

Now that we have ID3D11Fence support (any recent Win10) the query based system
should not be used. For older Windows using D3D11 we'll have less precise
estimation of the time it took to actually render, meaning the frame drop will
be less effective.

- - - - -


1 changed file:

- modules/video_output/win32/direct3d11.c


Changes:

=====================================
modules/video_output/win32/direct3d11.c
=====================================
@@ -105,7 +105,6 @@ struct vout_display_sys_t
     d3d_shader_compiler_t    shaders;
     d3d11_quad_t             picQuad;
 
-    ID3D11Asynchronous       *prepareWait;
 #ifdef HAVE_D3D11_4_H
     ID3D11Fence              *d3dRenderFence;
     ID3D11DeviceContext4     *d3dcontext4;
@@ -487,6 +486,7 @@ static bool SelectRenderPlane(void *opaque, size_t plane, ID3D11RenderTargetView
 static void PreparePicture(vout_display_t *vd, picture_t *picture, subpicture_t *subpicture,
                            vlc_tick_t date)
 {
+    VLC_UNUSED(date);
     vout_display_sys_t *sys = vd->sys;
 
     if (sys->picQuad.generic.textureFormat->formatTexture == DXGI_FORMAT_UNKNOWN)
@@ -627,14 +627,12 @@ static void PreparePicture(vout_display_t *vd, picture_t *picture, subpicture_t
         }
     }
 
-    vlc_tick_t render_start;
-    const char *wait_method = NULL;
-    if (sys->log_level >= 4)
-        render_start = vlc_tick_now();
 #ifdef HAVE_D3D11_4_H
     if (sys->d3dcontext4)
     {
-        wait_method = "fence";
+        vlc_tick_t render_start;
+        if (sys->log_level >= 4)
+            render_start = vlc_tick_now();
         if (sys->renderFence == UINT64_MAX)
             sys->renderFence = 0;
         else
@@ -645,34 +643,10 @@ static void PreparePicture(vout_display_t *vd, picture_t *picture, subpicture_t
         ID3D11DeviceContext4_Signal(sys->d3dcontext4, sys->d3dRenderFence, sys->renderFence);
 
         WaitForSingleObject(sys->renderFinished, INFINITE);
+        if (sys->log_level >= 4)
+            msg_Dbg(vd, "waited %" PRId64 " ms for the render fence", MS_FROM_VLC_TICK(vlc_tick_now() - render_start));
     }
-    else
 #endif
-    if (sys->prepareWait)
-    {
-        wait_method = "query";
-        ID3D11DeviceContext_End(sys->d3d_dev->d3dcontext, sys->prepareWait);
-
-        while (S_FALSE == ID3D11DeviceContext_GetData(sys->d3d_dev->d3dcontext,
-                                                      sys->prepareWait, NULL, 0, 0))
-        {
-            d3d11_device_unlock( sys->d3d_dev );
-            vlc_tick_t sleep_duration = (date - vlc_tick_now()) / 4;
-            if (sleep_duration <= VLC_TICK_FROM_MS(2))
-            {
-                // don't wait any longer, the display will likely be late
-                // we'll finish waiting during the Display call
-                break;
-            }
-            // wait a little until the rendering is done
-            SleepEx(MS_FROM_VLC_TICK(sleep_duration), TRUE);
-            d3d11_device_lock( sys->d3d_dev );
-        }
-    }
-    if (sys->log_level >= 4 && wait_method != NULL)
-    {
-        msg_Dbg(vd, "waited %" PRId64 " ms for the render %s", MS_FROM_VLC_TICK(vlc_tick_now() - render_start), wait_method);
-    }
 }
 
 static void Prepare(vout_display_t *vd, picture_t *picture,
@@ -729,25 +703,6 @@ static void Display(vout_display_t *vd, picture_t *picture)
 
     d3d11_device_lock( sys->d3d_dev );
     sys->swapCb(sys->outside_opaque);
-
-    if (sys->prepareWait)
-    {
-        vlc_tick_t start = 0;
-        while (S_FALSE == ID3D11DeviceContext_GetData(sys->d3d_dev->d3dcontext,
-                                                      sys->prepareWait, NULL, 0, 0))
-        {
-            d3d11_device_unlock( sys->d3d_dev );
-            if (start == 0)
-                start = vlc_tick_now();
-            // keep waiting until all rendering (plus extra) is known to be finished
-            // to let the vout thread things are not as smooth as it may think
-            SleepEx(2, TRUE);
-            d3d11_device_lock( sys->d3d_dev );
-        }
-        if (start != 0 && sys->log_level >= 4)
-            msg_Dbg(vd, "rendering wasn't finished, waited extra %lld ms", MS_FROM_VLC_TICK(vlc_tick_now() - start));
-    }
-
     d3d11_device_unlock( sys->d3d_dev );
 }
 
@@ -1162,13 +1117,7 @@ static int Direct3D11CreateGenericResources(vout_display_t *vd)
     {
         msg_Dbg(vd, "using GPU render fence");
     }
-    else
 #endif
-    {
-        D3D11_QUERY_DESC query = { 0 };
-        query.Query = D3D11_QUERY_EVENT;
-        ID3D11Device_CreateQuery(sys->d3d_dev->d3ddevice, &query, (ID3D11Query**)&sys->prepareWait);
-    }
 
     ID3D11BlendState *pSpuBlendState;
     D3D11_BLEND_DESC spuBlendDesc = { 0 };
@@ -1295,13 +1244,7 @@ static void Direct3D11DestroyResources(vout_display_t *vd)
         CloseHandle(sys->renderFinished);
         sys->renderFinished = NULL;
     }
-    else
 #endif
-    if (sys->prepareWait)
-    {
-        ID3D11Query_Release(sys->prepareWait);
-        sys->prepareWait = NULL;
-    }
 
     msg_Dbg(vd, "Direct3D11 resources destroyed");
 }



View it on GitLab: https://code.videolan.org/videolan/vlc/-/commit/141e07e12fd73ebd957d3d1227aa9bdbe58e3ef3

-- 
View it on GitLab: https://code.videolan.org/videolan/vlc/-/commit/141e07e12fd73ebd957d3d1227aa9bdbe58e3ef3
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