diff --git a/dlls/quartz/vmr9.c b/dlls/quartz/vmr9.c
index bee5a107185..d4331d321df 100644
--- a/dlls/quartz/vmr9.c
+++ b/dlls/quartz/vmr9.c
@@ -279,7 +279,7 @@ static HRESULT WINAPI VMR9_DoRenderSample(struct strmbase_renderer *iface, IMedi
         return hr;
     }
 
-    if (height > 0)
+    if (height > 0 && bitmap_header->biCompression == BI_RGB)
     {
         BYTE *dst = (BYTE *)locked_rect.pBits + (height * locked_rect.Pitch);
         const BYTE *src = data;
@@ -298,6 +298,8 @@ static HRESULT WINAPI VMR9_DoRenderSample(struct strmbase_renderer *iface, IMedi
         BYTE *dst = locked_rect.pBits;
         const BYTE *src = data;
 
+        height = abs(height);
+
         TRACE("Source pitch %u does not match dest pitch %u; copying manually.\n",
                 src_pitch, locked_rect.Pitch);