[wpe-2.46] Insert cencparser when available

Source/WebCore/platform/graphics/gstreamer/eme/WebKitCommonEncryptionDecryptorGStreamer.cpp

@@ -80,6 +80,7 @@ static gboolean acceptCaps(GstBaseTransform*, GstPadDirection, GstCaps*);
 static GstFlowReturn transformInPlace(GstBaseTransform*, GstBuffer*);
 static gboolean sinkEventHandler(GstBaseTransform*, GstEvent*);
 static void setContext(GstElement*, GstContext*);
+static bool isCDMProxyAvailable(WebKitMediaCommonEncryptionDecrypt* self);
 
 GST_DEBUG_CATEGORY(webkit_media_common_encryption_decrypt_debug_category);
 #define GST_CAT_DEFAULT webkit_media_common_encryption_decrypt_debug_category
@@ -170,13 +171,20 @@ static GstCaps* transformCaps(GstBaseTransform* base, GstPadDirection direction,
                 gst_structure_remove_fields(outgoingStructure.get(), "base-profile", "codec_data", "height", "framerate", "level", "pixel-aspect-ratio", "profile", "rate", "width", nullptr);
 
                 auto name = WebCore::gstStructureGetName(incomingStructure);
-                gst_structure_set(outgoingStructure.get(), "protection-system", G_TYPE_STRING, klass->protectionSystemId(self),
-                    "original-media-type", G_TYPE_STRING, reinterpret_cast<const char*>(name.rawCharacters()) , nullptr);
-
-                // GST_PROTECTION_UNSPECIFIED_SYSTEM_ID was added in the GStreamer
-                // developement git master which will ship as version 1.16.0.
-                gst_structure_set_name(outgoingStructure.get(), !g_strcmp0(klass->protectionSystemId(self),
-                    GST_PROTECTION_UNSPECIFIED_SYSTEM_ID) ? "application/x-webm-enc" : "application/x-cenc");
+                if (!isCDMProxyAvailable(self)) {
+                    GST_WARNING_OBJECT(base, "CDM proxy is not available yet, transformed CAPs might be inaccurate.");
+                    gst_structure_set(outgoingStructure.get(),
+                        "original-media-type", G_TYPE_STRING, reinterpret_cast<const char*>(name.rawCharacters()) , nullptr);
+                    gst_structure_set_name(outgoingStructure.get(), "application/x-cenc");
+                } else {
+                    gst_structure_set(outgoingStructure.get(), "protection-system", G_TYPE_STRING, klass->protectionSystemId(self),
+                        "original-media-type", G_TYPE_STRING, reinterpret_cast<const char*>(name.rawCharacters()) , nullptr);
+
+                    // GST_PROTECTION_UNSPECIFIED_SYSTEM_ID was added in the GStreamer
+                    // developement git master which will ship as version 1.16.0.
+                    gst_structure_set_name(outgoingStructure.get(), !g_strcmp0(klass->protectionSystemId(self),
+                        GST_PROTECTION_UNSPECIFIED_SYSTEM_ID) ? "application/x-webm-enc" : "application/x-cenc");
+                }
             }
         }
 

Source/WebCore/platform/graphics/gstreamer/eme/WebKitThunderParser.cpp

@@ -238,6 +238,127 @@ static void webkitMediaThunderParserConstructed(GObject* object)
     gst_bin_sync_children_states(GST_BIN_CAST(self));
 }
 
+static void tryInsertCencparser(WebKitMediaThunderParser* self)
+{
+    auto cencparserFactory = adoptGRef(gst_element_factory_find("cencparser"));
+    if (!cencparserFactory)
+        return;
+
+    auto sinkPad = adoptGRef(gst_element_get_static_pad(GST_ELEMENT(self), "sink"));
+    auto peerPad = adoptGRef(gst_pad_get_peer(sinkPad.get()));
+    auto peerCaps = adoptGRef(gst_pad_get_current_caps (peerPad.get()));
+    if (!peerCaps) {
+        peerCaps = adoptGRef(gst_pad_query_caps(peerPad.get(), nullptr));
+        if (!peerCaps) {
+            GST_WARNING_OBJECT (self, "Couldn't get caps from peer.");
+            return;
+        }
+    }
+
+    GST_DEBUG_OBJECT(self, "Have type: %" GST_PTR_FORMAT, peerCaps.get());
+
+    // Cenc parser is required only for h264 and h265 video streams.
+    static constexpr std::array<ASCIILiteral, 2> s_cencparserMediaTypes = { "video/x-h264"_s, "video/x-h265"_s };
+    bool shouldInsertCencparser = std::any_of(
+        s_cencparserMediaTypes.begin(), s_cencparserMediaTypes.end(),
+        [&peerCaps](const auto& mediaType) { return doCapsHaveType(peerCaps.get(), mediaType.characters()); });
+    if (!shouldInsertCencparser) {
+        GST_DEBUG_OBJECT (self, "Cencparser is not required.");
+        return;
+    }
+
+    // Sanity check
+    auto currentSinkPadTarget = adoptGRef(gst_ghost_pad_get_target(GST_GHOST_PAD(sinkPad.get())));
+    auto currentSinkPadTargetParent = adoptGRef(gst_pad_get_parent_element(currentSinkPadTarget.get()));
+    if (gst_element_get_factory(currentSinkPadTargetParent.get()) == cencparserFactory) {
+        GST_DEBUG_OBJECT(self, "Cencparser is already inserted.");
+        return;
+    }
+
+    // Create and setup cencparser
+    GstElement *cencparser = gst_element_factory_create(cencparserFactory.get(), nullptr);
+    if (!cencparser) {
+        GST_WARNING_OBJECT (self, "Could not create cencparser.");
+        return;
+    }
+    gst_bin_add_many(GST_BIN_CAST(self), cencparser, nullptr);
+    if (!gst_element_sync_state_with_parent(cencparser))
+        GST_WARNING_OBJECT(self, "Failed to sync state of '%s' with parent bin.", GST_ELEMENT_NAME(cencparser));
+    gst_base_transform_set_passthrough(
+        GST_BASE_TRANSFORM(self->priv->decryptor.get()), !WebCore::areEncryptedCaps(peerCaps.get()));
+
+    // In passthrough mode, decryptor returns an empty caps result for a caps
+    // query on sink pad. This is because of lack of clear caps in its sink
+    // pad's template. That is the intersection of transformed clear caps with
+    // encrypted caps from the template produces an empty result.
+    // This empty result causes capsfilter linking to fail inside cencparser.
+    // Workaround: intercept cencparser's caps query and append the media types
+    // that cencparser expects.
+    auto decryptorSinkPad = adoptGRef(gst_element_get_static_pad(self->priv->decryptor.get(), "sink"));
+    gst_pad_add_probe(
+        decryptorSinkPad.get(),
+        static_cast<GstPadProbeType>(GST_PAD_PROBE_TYPE_PULL | GST_PAD_PROBE_TYPE_QUERY_DOWNSTREAM),
+        reinterpret_cast<GstPadProbeCallback>(+[](GstPad* pad, GstPadProbeInfo* info, gpointer userData) -> GstPadProbeReturn {
+            if (!GST_IS_QUERY(info->data) || GST_QUERY_TYPE(GST_PAD_PROBE_INFO_QUERY(info)) != GST_QUERY_CAPS)
+                return GST_PAD_PROBE_OK;
+
+            GRefPtr<GstElement> decryptor = adoptGRef(gst_pad_get_parent_element(pad));
+            if (!gst_base_transform_is_passthrough(GST_BASE_TRANSFORM(decryptor.get())))
+                return GST_PAD_PROBE_OK;
+
+            GstCaps *result = nullptr;
+            GstQuery *query = GST_PAD_PROBE_INFO_QUERY(info);
+            gst_query_parse_caps_result (query, &result);
+            if (gst_caps_is_empty(result)) {
+                GRefPtr<GstCaps> tmp = adoptGRef(gst_caps_new_empty());
+                for (const auto& mediaType : s_cencparserMediaTypes) {
+                    gst_caps_append_structure(tmp.get(), gst_structure_new_empty(mediaType.characters()));
+                }
+                GstCaps *filter = nullptr;
+                gst_query_parse_caps (query, &filter);
+                if (filter) {
+                    GstCaps* intersection;
+                    intersection = gst_caps_intersect_full(filter, tmp.get(), GST_CAPS_INTERSECT_FIRST);
+                    gst_caps_append (result, intersection);
+                } else {
+                    gst_caps_append (result, tmp.leakRef());
+                }
+                GST_DEBUG_OBJECT(pad, "Enriched result caps: %" GST_PTR_FORMAT, result);
+            }
+            return GST_PAD_PROBE_OK;
+        }), nullptr, nullptr);
+
+    GST_DEBUG_OBJECT(self, "Inserting cencparser %" GST_PTR_FORMAT " before decryptor %" GST_PTR_FORMAT, cencparser, self->priv->decryptor.get());
+    GRefPtr<GstPad> cencparserSinkPad = adoptGRef(gst_element_get_static_pad(cencparser, "sink"));
+    if (!gst_ghost_pad_set_target(GST_GHOST_PAD(sinkPad.get()), cencparserSinkPad.get())) {
+        GST_WARNING_OBJECT (self, "Could not change sink pad target.");
+    } else if (!gst_element_link_pads_full(cencparser, "src", self->priv->decryptor.get(), "sink", GST_PAD_LINK_CHECK_NOTHING)) {
+        GST_WARNING_OBJECT (self, "Failed to link %" GST_PTR_FORMAT " with %" GST_PTR_FORMAT, cencparser, self->priv->decryptor.get());
+    } else {
+        GST_DEBUG_OBJECT (self, "Successfully inserted cencparser %" GST_PTR_FORMAT, cencparser);
+    }
+}
+
+static GstStateChangeReturn webkitMediaThunderParserChangeState(GstElement* element, GstStateChange transition)
+{
+    WebKitMediaThunderParser* self = WEBKIT_MEDIA_THUNDER_PARSER(element);
+
+    switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY: {
+        tryInsertCencparser(self);
+        break;
+    }
+    default:
+        break;
+    }
+
+    GstStateChangeReturn result = GST_ELEMENT_CLASS(webkit_media_thunder_parser_parent_class)->change_state(element, transition);
+
+    // Add post-transition code here.
+
+    return result;
+}
+
 static void webkit_media_thunder_parser_class_init(WebKitMediaThunderParserClass* klass)
 {
     GST_DEBUG_CATEGORY_INIT(webkitMediaThunderParserDebugCategory, "webkitthunderparser", 0, "Thunder parser");
@@ -246,6 +367,8 @@ static void webkit_media_thunder_parser_class_init(WebKitMediaThunderParserClass
     objectClass->constructed = webkitMediaThunderParserConstructed;
 
     auto elementClass = GST_ELEMENT_CLASS(klass);
+    elementClass->change_state = GST_DEBUG_FUNCPTR(webkitMediaThunderParserChangeState);
+
     auto padTemplateCaps = createThunderParseSinkPadTemplateCaps();
     gst_element_class_add_pad_template(elementClass, gst_pad_template_new("sink", GST_PAD_SINK, GST_PAD_ALWAYS, padTemplateCaps.get()));
     gst_element_class_add_pad_template(elementClass, gst_static_pad_template_get(&thunderParseSrcTemplate));