[GStreamer] Ensure GStreamer is initialized before using the Quirks

https://bugs.webkit.org/show_bug.cgi?id=303326

Reviewed by Philippe Normand.

GStreamerQuirksManager requires GStreamer to be initialized, which
does not happen soon enough if neither canPlayType() nor isTypeSupported() has
been called before, so in those cases no quirks are applied.

However, the quirks manager may be used in other processes, e.g. NetworkProcess
when determining support for a MIME type. To avoid issues, we should
only fully init GStreamer if on the WebProcess, and otherwise go for
a minimal initialization.

* Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.cpp:
(WebCore::ensureGStreamerInitializedNonWebProcess):
Added as a counterpart to ensureGStreamerInitialized, only does minimal init.
* Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.h:
* Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.cpp:
(WebCore::GStreamerRegistryScanner::GStreamerRegistryScanner):
Use the new function to initialize gst if in the UIProcess
* Source/WebCore/platform/gstreamer/GStreamerQuirks.cpp:
(WebCore::GStreamerQuirksManager::GStreamerQuirksManager):
Init GStreamer using either of the two methods

Original author: Andrzej Surdej <[email protected]>

See: #1584
Canonical link: https://commits.webkit.org/303982@main

Author: vivienne-w

Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.cpp

@@ -347,6 +347,22 @@ Vector<String> extractGStreamerOptionsFromCommandLine()
     return options;
 }
 
+bool ensureGStreamerInitializedNonWebProcess()
+{
+    RELEASE_ASSERT(!isInWebProcess());
+
+    static std::once_flag onceFlag;
+    static bool isGStreamerInitialized;
+    std::call_once(onceFlag, [] {
+        GUniqueOutPtr<GError> error;
+        isGStreamerInitialized = gst_init_check(nullptr, nullptr, &error.outPtr());
+        ASSERT_WITH_MESSAGE(isGStreamerInitialized, "GStreamer initialization failed: %s", error ? error->message : "unknown error occurred");
+        GST_DEBUG_CATEGORY_INIT(webkit_gst_common_debug, "webkitcommon", 0, "WebKit Common utilities");
+    });
+
+    return isGStreamerInitialized;
+}
+
 bool ensureGStreamerInitialized()
 {
     // WARNING: Please note this function can be called from any thread, for instance when creating

Source/WebCore/platform/graphics/gstreamer/GStreamerCommon.h

@@ -80,6 +80,7 @@ bool doCapsHaveType(const GstCaps*, const char*);
 bool areEncryptedCaps(const GstCaps*);
 Vector<String> extractGStreamerOptionsFromCommandLine();
 void setGStreamerOptionsFromUIProcess(Vector<String>&&);
+bool ensureGStreamerInitializedNonWebProcess();
 bool ensureGStreamerInitialized();
 void registerWebKitGStreamerElements();
 void registerWebKitGStreamerVideoEncoder();

Source/WebCore/platform/graphics/gstreamer/GStreamerRegistryScanner.cpp

@@ -362,7 +362,7 @@ GStreamerRegistryScanner::GStreamerRegistryScanner(bool isMediaSource)
     else {
         // This is still needed, mostly because of the webkit_web_view_can_show_mime_type() public API (so
         // running from UIProcess).
-        gst_init(nullptr, nullptr);
+        ensureGStreamerInitializedNonWebProcess();
     }
 
     GST_DEBUG_CATEGORY_INIT(webkit_media_gst_registry_scanner_debug, "webkitregistryscanner", 0, "WebKit GStreamer registry scanner");

Source/WebCore/platform/gstreamer/GStreamerQuirks.cpp

@@ -38,6 +38,7 @@
 #include "GStreamerQuirkWesteros.h"
 #include <wtf/NeverDestroyed.h>
 #include <wtf/OptionSet.h>
+#include <wtf/RuntimeApplicationChecks.h>
 #include <wtf/text/StringView.h>
 
 namespace WebCore {
@@ -56,6 +57,12 @@ GStreamerQuirksManager::GStreamerQuirksManager(bool isForTesting, bool loadQuirk
 {
     static std::once_flag debugRegisteredFlag;
     std::call_once(debugRegisteredFlag, [] {
+        if (isInWebProcess())
+            ensureGStreamerInitialized();
+        else
+            // This is needed, e.g. when running in NetworkProcess to determine MIME type support
+            ensureGStreamerInitializedNonWebProcess();
+
         GST_DEBUG_CATEGORY_INIT(webkit_quirks_debug, "webkitquirks", 0, "WebKit Quirks");
     });