diff --git a/src/gallium/drivers/d3d12/d3d12_interop_public.h b/src/gallium/drivers/d3d12/d3d12_interop_public.h
index 27ece99261c..0f7521e7eb5 100644
--- a/src/gallium/drivers/d3d12/d3d12_interop_public.h
+++ b/src/gallium/drivers/d3d12/d3d12_interop_public.h
@@ -34,6 +34,18 @@ struct ID3D12Device;
 struct ID3D12CommandQueue;
 struct ID3D12Resource;
 
+struct d3d12_interop_video_buffer_associated_data
+{
+   /*
+    * Subresource index within the underlying ID3D12Resource
+    * representing this video buffer.
+    *
+    * This is useful when the underlying resource is a texture array
+    * and each video buffer maps to a different subresource within it.
+    */
+   uint32_t subresource_index;
+};
+
 struct d3d12_interop_device_info {
    uint64_t adapter_luid;
    ID3D12Device *device;
diff --git a/src/gallium/drivers/d3d12/d3d12_video_buffer.cpp b/src/gallium/drivers/d3d12/d3d12_video_buffer.cpp
index 44aa326c637..5c4121a97f8 100644
--- a/src/gallium/drivers/d3d12/d3d12_video_buffer.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_video_buffer.cpp
@@ -65,7 +65,7 @@ d3d12_video_buffer_create_impl(struct pipe_context *pipe,
    pD3D12VideoBuffer->base.height        = tmpl->height;
    pD3D12VideoBuffer->base.interlaced    = tmpl->interlaced;
    pD3D12VideoBuffer->base.contiguous_planes = true;
-   pD3D12VideoBuffer->base.associated_data = nullptr;
+   pD3D12VideoBuffer->base.associated_data = &pD3D12VideoBuffer->d3d12_video_buffer_associated_data;
    pD3D12VideoBuffer->idx_texarray_slots = 0;
    pD3D12VideoBuffer->m_spVideoTexArrayDPBPoolInUse.reset();
 
@@ -535,6 +535,7 @@ d3d12_video_create_dpb_buffer_texarray(struct pipe_video_codec *codec,
       if (((*pD3D12Enc->m_spVideoTexArrayDPBPoolInUse) & (1 << i)) == 0)
       {
          buf->idx_texarray_slots = i;
+         buf->d3d12_video_buffer_associated_data.subresource_index = i;
          (*pD3D12Enc->m_spVideoTexArrayDPBPoolInUse) |= (1 << buf->idx_texarray_slots); // Mark i-th bit as used
          bFoundEmptySlot = true;
          break;
diff --git a/src/gallium/drivers/d3d12/d3d12_video_buffer.h b/src/gallium/drivers/d3d12/d3d12_video_buffer.h
index 378bfb85bba..20291ed77fc 100644
--- a/src/gallium/drivers/d3d12/d3d12_video_buffer.h
+++ b/src/gallium/drivers/d3d12/d3d12_video_buffer.h
@@ -30,6 +30,7 @@
 #include "vl/vl_defines.h"
 #include <vector>
 #include "d3d12_video_types.h"
+#include "d3d12_interop_public.h"
 
 ///
 /// Pipe video buffer interface starts
@@ -107,6 +108,7 @@ struct d3d12_video_buffer
    // in the function d3d12_video_enc::d3d12_video_create_dpb_buffer()
    // Points to the same address as d3d12_video_encoder::m_spVideoTexArrayDPBPoolInUse
    std::shared_ptr<uint32_t> m_spVideoTexArrayDPBPoolInUse;
+   struct d3d12_interop_video_buffer_associated_data d3d12_video_buffer_associated_data = {};
 };
 
 ///