Merge commit '2e219b491bcc0845248345fdad31231b081e06d1'

* commit '2e219b491bcc0845248345fdad31231b081e06d1':
  hwcontext_cuda: implement device creation

Merged-by: Hendrik Leppkes <h.leppkes@gmail.com>

libavutil/hwcontext_cuda.c

@@ -253,6 +253,49 @@ static int cuda_transfer_data_to(AVHWFramesContext *ctx, AVFrame *dst,
     return 0;
 }
 
+static void cuda_device_free(AVHWDeviceContext *ctx)
+{
+    AVCUDADeviceContext *hwctx = ctx->hwctx;
+    cuCtxDestroy(hwctx->cuda_ctx);
+}
+
+static int cuda_device_create(AVHWDeviceContext *ctx, const char *device,
+                              AVDictionary *opts, int flags)
+{
+    AVCUDADeviceContext *hwctx = ctx->hwctx;
+    CUdevice cu_device;
+    CUcontext dummy;
+    CUresult err;
+    int device_idx = 0;
+
+    if (device)
+        device_idx = strtol(device, NULL, 0);
+
+    err = cuInit(0);
+    if (err != CUDA_SUCCESS) {
+        av_log(ctx, AV_LOG_ERROR, "Could not initialize the CUDA driver API\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    err = cuDeviceGet(&cu_device, device_idx);
+    if (err != CUDA_SUCCESS) {
+        av_log(ctx, AV_LOG_ERROR, "Could not get the device number %d\n", device_idx);
+        return AVERROR_UNKNOWN;
+    }
+
+    err = cuCtxCreate(&hwctx->cuda_ctx, 0, cu_device);
+    if (err != CUDA_SUCCESS) {
+        av_log(ctx, AV_LOG_ERROR, "Error creating a CUDA context\n");
+        return AVERROR_UNKNOWN;
+    }
+
+    cuCtxPopCurrent(&dummy);
+
+    ctx->free = cuda_device_free;
+
+    return 0;
+}
+
 const HWContextType ff_hwcontext_type_cuda = {
     .type                 = AV_HWDEVICE_TYPE_CUDA,
     .name                 = "CUDA",
@@ -260,6 +303,7 @@ const HWContextType ff_hwcontext_type_cuda = {
     .device_hwctx_size    = sizeof(AVCUDADeviceContext),
     .frames_priv_size     = sizeof(CUDAFramesContext),
 
+    .device_create        = cuda_device_create,
     .frames_init          = cuda_frames_init,
     .frames_get_buffer    = cuda_get_buffer,
     .transfer_get_formats = cuda_transfer_get_formats,