[PATCH] mfplat/buffer: Lock D3D9 surfaces with usage flags.

[Giovanni Mascellani]

This way the underlying implementation is able to save some copies.

Running CHRONO TRIGGER with this commit saves 1-2 ms per frame in the sample
copier on my computer.

Signed-off-by: Giovanni Mascellani 
---
 dlls/mfplat/buffer.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dlls/mfplat/buffer.c b/dlls/mfplat/buffer.c
index f161bb29d80..c45309e1c31 100644
--- a/dlls/mfplat/buffer.c
+++ b/dlls/mfplat/buffer.c
@@ -385,7 +385,7 @@ static HRESULT WINAPI d3d9_surface_buffer_Lock(IMFMediaBuffer *iface, BYTE **dat

if (SUCCEEDED(hr))
         {
-            hr = IDirect3DSurface9_LockRect(buffer->d3d9_surface.surface, &rect, NULL, 0);
+            hr = IDirect3DSurface9_LockRect(buffer->d3d9_surface.surface, &rect, NULL, D3DLOCK_READONLY);
             if (SUCCEEDED(hr))
             {
                 copy_image(buffer, buffer->_2d.linear_buffer, buffer->_2d.width, rect.pBits, rect.Pitch,
@@ -425,7 +425,7 @@ static HRESULT WINAPI d3d9_surface_buffer_Unlock(IMFMediaBuffer *iface)
     {
         D3DLOCKED_RECT rect;

-        if (SUCCEEDED(hr = IDirect3DSurface9_LockRect(buffer->d3d9_surface.surface, &rect, NULL, 0)))
+        if (SUCCEEDED(hr = IDirect3DSurface9_LockRect(buffer->d3d9_surface.surface, &rect, NULL, D3DLOCK_DISCARD)))
         {
             copy_image(buffer, rect.pBits, rect.Pitch, buffer->_2d.linear_buffer, buffer->_2d.width,
                     buffer->_2d.width, buffer->_2d.height);