From e2aa76db79328b7f61536dd19d0373cf920395ad Mon Sep 17 00:00:00 2001
From: Seppo Yli-Olli <seppo.yli-olli@iki.fi>
Date: Tue, 21 Apr 2020 13:33:54 +0300
Subject: [PATCH] Have strict version check for OpenH264 to avoid ABI issues
 This fixes #1274 and no longer trusts soname alone

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1206>
---
 ext/openh264/gstopenh264plugin.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/ext/openh264/gstopenh264plugin.c b/ext/openh264/gstopenh264plugin.c
index 99c428ab7d..10b0d4f071 100644
--- a/ext/openh264/gstopenh264plugin.c
+++ b/ext/openh264/gstopenh264plugin.c
@@ -32,17 +32,29 @@
 #endif
 
 #include <gst/gst.h>
+#include <wels/codec_api.h>
+#include <wels/codec_ver.h>
+#include <string.h>
 #include "gstopenh264dec.h"
 #include "gstopenh264enc.h"
 
 static gboolean
 plugin_init (GstPlugin * plugin)
 {
-  gst_element_register (plugin, "openh264dec", GST_RANK_MARGINAL,
-      GST_TYPE_OPENH264DEC);
-  gst_element_register (plugin, "openh264enc", GST_RANK_MARGINAL,
-      GST_TYPE_OPENH264ENC);
-
+  /* g_stCodecVersion is the version detected at build time as defined in the
+   * headers and WelsGetCodecVersion() is the version detected at runtime.
+   * This is a safeguard to avoid crashes since OpenH264  has been changing
+   * ABI without changing the SONAME.
+   */
+  OpenH264Version libver = WelsGetCodecVersion ();
+  if (memcmp (&libver, &g_stCodecVersion, sizeof (libver))) {
+    gst_element_register (plugin, "openh264dec", GST_RANK_MARGINAL,
+        GST_TYPE_OPENH264DEC);
+    gst_element_register (plugin, "openh264enc", GST_RANK_MARGINAL,
+        GST_TYPE_OPENH264ENC);
+  } else {
+    GST_ERROR ("Incorrect library version loaded, expecting %s", g_strCodecVer);
+  }
   return TRUE;
 }