hwcontext: add a CUDA implementation

libavutil/hwcontext_cuda.h

@@ -0,0 +1,46 @@
+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+
+#ifndef AVUTIL_HWCONTEXT_CUDA_H
+#define AVUTIL_HWCONTEXT_CUDA_H
+
+#include <cuda.h>
+
+#include "pixfmt.h"
+
+/**
+ * @file
+ * An API-specific header for AV_HWDEVICE_TYPE_CUDA.
+ *
+ * This API supports dynamic frame pools. AVHWFramesContext.pool must return
+ * AVBufferRefs whose data pointer is a CUdeviceptr.
+ */
+
+/**
+ * This struct is allocated as AVHWDeviceContext.hwctx
+ */
+typedef struct AVCUDADeviceContext {
+    CUcontext cuda_ctx;
+} AVCUDADeviceContext;
+
+/**
+ * AVHWFramesContext.hwctx is currently not used
+ */
+
+#endif /* AVUTIL_HWCONTEXT_CUDA_H */