cuda: fix crash if no cuda loaded.

src/VideoDecoderCUDA.cpp

@@ -130,6 +130,8 @@ public:
         nb_dec_surface = 20;
         if (!can_load)
             return;
+        if (!isLoaded()) //cuda_api
+            return;
         bitstream_filter_ctx = av_bitstream_filter_init("h264_mp4toannexb");
         Q_ASSERT_X(bitstream_filter_ctx, "av_bitstream_filter_init", "Unknown bitstream filter");
         initCuda();
@@ -137,6 +139,8 @@ public:
     ~VideoDecoderCUDAPrivate() {
         if (!can_load)
             return;
+        if (!isLoaded()) //cuda_api
+            return;
         av_bitstream_filter_close(bitstream_filter_ctx);
         releaseCuda();
     }
@@ -267,6 +271,8 @@ bool VideoDecoderCUDA::prepare()
         qWarning("VideoDecoderCUDA::prepare(): CUVID library not available");
         return false;
     }
+    if (!d.isLoaded()) //cuda_api
+        return false;
     // max decoder surfaces is computed in createCUVIDDecoder. createCUVIDParser use the value
     return d.createCUVIDDecoder(mapCodecFromFFmpeg(d.codec_ctx->codec_id), d.codec_ctx->coded_width, d.codec_ctx->coded_height)
             && d.createCUVIDParser();

src/cuda/cuda_api.cpp

@@ -6,8 +6,10 @@
 
 class cuda_api::context {
 public:
+    context()
+        : loaded(true) {
 #if !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
-    context() {
+        loaded = false;
         cuda_dll.setFileName("cuda");
         if (!cuda_dll.isLoaded())
             cuda_dll.load();
@@ -15,10 +17,22 @@ public:
             cuda_dll.setFileName("nvcuda");
             cuda_dll.load();
         }
+        if (!cuda_dll.isLoaded()) {
+            qWarning("can not load cuda!");
+            return;
+        }
         cuvid_dll.setFileName("nvcuvid");
         cuvid_dll.load();
+        if (!cuvid_dll.isLoaded()) {
+            qWarning("can not load nvcuvid!");
+            return;
+        }
+        loaded = true;
+#endif // !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
     }
+#if !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
     ~context() {
+        loaded = false;
         cuvid_dll.unload();
         cuda_dll.unload();
     }
@@ -26,6 +40,7 @@ public:
     QLibrary cuda_dll;
     QLibrary cuvid_dll;
 #endif // !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
+    bool loaded;
 };
 
 cuda_api::cuda_api()
@@ -38,6 +53,11 @@ cuda_api::~cuda_api()
     delete ctx;
 }
 
+bool cuda_api::isLoaded() const
+{
+    return ctx->loaded;
+}
+
 #if !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
 ////////////////////////////////////////////////////
 /// CUDA functions

src/cuda/cuda_api.h

@@ -28,6 +28,7 @@ class cuda_api {
 public:
     cuda_api();
     ~cuda_api();
+    bool isLoaded() const;
 #if !NV_CONFIG(DLLAPI_CUDA) && !defined(CUDA_LINK)
     ////////////////////////////////////////////////////
     /// CUDA functions