hw/amf: add a helper to create an AMFContext

modules/hw/amf/amf_helper.c

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+// amf_helper.c: AMD Advanced Media Framework helper
+// Copyright © 2024 VideoLabs, VLC authors and VideoLAN
+
+// Authors: Steve Lhomme <robux4@videolabs.io>
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "amf_helper.h"
+
+#include <vlc_common.h>
+
+int vlc_AMFCreateContext(struct vlc_amf_context *c)
+{
+#ifdef _WIN32
+# if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP)
+    HMODULE hLib = LoadLibraryA(AMF_DLL_NAMEA);
+    if (hLib == NULL)
+        return VLC_ENOTSUP;
+
+    amf_uint64 version = 0;
+    AMF_RESULT res;
+    AMFQueryVersion_Fn queryVersion = (AMFQueryVersion_Fn)GetProcAddress(hLib, AMF_QUERY_VERSION_FUNCTION_NAME);
+    if (unlikely(queryVersion == NULL))
+        goto error;
+    res = queryVersion(&version);
+    if (unlikely(res != AMF_OK))
+        goto error;
+
+    c->pFactory = NULL;
+    c->Context = NULL;
+
+    AMFInit_Fn init = (AMFInit_Fn)GetProcAddress(hLib, AMF_INIT_FUNCTION_NAME);
+    res = init(version, &c->pFactory);
+    if (unlikely(res != AMF_OK))
+        goto error;
+
+    res = c->pFactory->pVtbl->CreateContext(c->pFactory, &c->Context);
+    if (res != AMF_OK || c->Context == NULL)
+        goto error;
+
+    c->Private = hLib;
+    return VLC_SUCCESS;
+
+error:
+    FreeLibrary(hLib);
+    return VLC_ENOTSUP;
+
+# else // !WINAPI_PARTITION_DESKTOP
+    // we can't load external DLLs in UWP
+    return VLC_ENOTSUP;
+# endif // !WINAPI_PARTITION_DESKTOP
+
+#else
+    return NULL; // TODO
+#endif
+}
+
+void vlc_AMFReleaseContext(struct vlc_amf_context *c)
+{
+    c->Context->pVtbl->Terminate(c->Context);
+    c->Context->pVtbl->Release(c->Context);
+#ifdef _WIN32
+    FreeLibrary(c->Private);
+#endif
+}

modules/hw/amf/amf_helper.h

@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+// amf_helper.h: AMD Advanced Media Framework helper
+// Copyright © 2024 VideoLabs, VLC authors and VideoLAN
+
+// Authors: Steve Lhomme <robux4@videolabs.io>
+
+#ifndef VLC_AMF_HELPER_H
+#define VLC_AMF_HELPER_H
+
+#include <AMF/core/Context.h>
+#include <AMF/core/Factory.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct vlc_amf_context
+{
+#ifdef __cplusplus
+    amf::AMFFactory *pFactory;
+    amf::AMFContext *Context;
+#else
+    AMFFactory      *pFactory;
+    AMFContext      *Context;
+#endif
+    void            *Private;
+};
+
+int vlc_AMFCreateContext(struct vlc_amf_context *);
+void vlc_AMFReleaseContext(struct vlc_amf_context *);
+
+#ifdef __cplusplus
+} // extern "C"
+#endif
+
+#endif // VLC_AMF_HELPER_H