[SOLVED] Derive qsv hwdevice from D3D11VA hwdevice using FFMPEG

Derive qsv hwdevice from D3D11VA hwdevice using FFMPEG

I'm trying to derive a QSV hwcontext from D3D11VA device in order to encode d3d11 frames but I'm getting an error when calling av_hwdevice_ctx_create_derived.

  buffer_t ctx_buf { av_hwdevice_ctx_alloc(AV_HWDEVICE_TYPE_D3D11VA) };

  auto ctx = (AVD3D11VADeviceContext *)((AVHWDeviceContext *)ctx_buf->data)->hwctx;

  std::fill_n((std::uint8_t *)ctx, sizeof(AVD3D11VADeviceContext), 0);

  auto device = (ID3D11Device *)hwdevice_ctx->data;

  device->AddRef();
  ctx->device = device;

  ctx->lock_ctx = (void *)1;
  ctx->lock     = do_nothing;
  ctx->unlock   = do_nothing;

  auto err = av_hwdevice_ctx_init(ctx_buf.get());

and then I call

  av_hwdevice_ctx_create_derived(&derive_hw_device_ctx, AV_HWDEVICE_TYPE_QSV, ctx_buf.get(), 0);

I'm seeing this in the log:

[AVHWDeviceContext @ 000001de119a9b80] Initialize MFX session: API version is 1.35, implementation version is 1.30
[AVHWDeviceContext @ 000001de119a9b80] Error setting child device handle: -16

Please let me know if you have any idea how to fix it or a different approach to encode d3d11 frames on QSV encoder.

Thank you.

OS: windows 10 64bits
CPU: Intel i5-8400
Graphics card: Nvidia GT1030 (has no hw encoder)

Solution

Adding this to d3d11 device solved the issue:

ID3D10Multithread *pMultithread;

  status = device->QueryInterface(IID_ID3D10Multithread, (void **)&pMultithread);
  if(SUCCEEDED(status)) {
    pMultithread->SetMultithreadProtected(TRUE);
    Release(pMultithread);
  }