From ccbb31c14b766ef666ef2daa8c467e478183a957 Mon Sep 17 00:00:00 2001
From: Luca Barbato <lu_zero@gentoo.org>
Date: Mon, 25 Sep 2017 09:57:30 +0000
Subject: [PATCH] qsv: Make sure the session is set with the latest version

It is needed to have the calls to MFXJoinSession succeed.
---
 libavutil/hwcontext_qsv.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/libavutil/hwcontext_qsv.c b/libavutil/hwcontext_qsv.c
index e0f6875b40..5018a05b9a 100644
--- a/libavutil/hwcontext_qsv.c
+++ b/libavutil/hwcontext_qsv.c
@@ -1029,6 +1029,23 @@ static int qsv_device_derive_from_child(AVHWDeviceContext *ctx,
         goto fail;
     }
 
+    err = MFXQueryVersion(hwctx->session, &ver);
+    if (err != MFX_ERR_NONE) {
+        av_log(ctx, AV_LOG_ERROR, "Error querying an MFX session: %d.\n", err);
+        ret = AVERROR_UNKNOWN;
+        goto fail;
+    }
+
+    MFXClose(hwctx->session);
+
+    err = MFXInit(implementation, &ver, &hwctx->session);
+    if (err != MFX_ERR_NONE) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Error initializing an MFX session: %d.\n", err);
+        ret = AVERROR_UNKNOWN;
+        goto fail;
+    }
+
     err = MFXVideoCORE_SetHandle(hwctx->session, handle_type, handle);
     if (err != MFX_ERR_NONE) {
         av_log(ctx, AV_LOG_ERROR, "Error setting child device handle: "