C API for extractor plugins
Define a C extractor plugin API, along with some helpers
so extractors can still be implemented in C++ if desired.
Bug: 111407253
Test: build, boot, play some files
Change-Id: Iba947381441769d77929b4235cdb4a4cd5d4f606
diff --git a/include/media/MediaExtractorPluginApi.h b/include/media/MediaExtractorPluginApi.h
new file mode 100644
index 0000000..30c2b05
--- /dev/null
+++ b/include/media/MediaExtractorPluginApi.h
@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2018 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef MEDIA_EXTRACTOR_PLUGIN_API_H_
+#define MEDIA_EXTRACTOR_PLUGIN_API_H_
+
+#include <utils/Errors.h> // for status_t
+
+namespace android {
+
+struct MediaTrack;
+class MetaDataBase;
+class DataSourceBase;
+
+extern "C" {
+
+struct CMediaExtractor {
+ void *data;
+
+ void (*free)(void *data);
+ size_t (*countTracks)(void *data);
+ MediaTrack* (*getTrack)(void *data, size_t index);
+ status_t (*getTrackMetaData)(
+ void *data,
+ MetaDataBase& meta,
+ size_t index, uint32_t flags);
+
+ status_t (*getMetaData)(void *data, MetaDataBase& meta);
+ uint32_t (*flags)(void *data);
+ status_t (*setMediaCas)(void *data, const uint8_t* casToken, size_t size);
+ const char * (*name)(void *data);
+};
+
+typedef CMediaExtractor* (*CreatorFunc)(DataSourceBase *source, void *meta);
+typedef void (*FreeMetaFunc)(void *meta);
+
+// The sniffer can optionally fill in an opaque object, "meta", that helps
+// the corresponding extractor initialize its state without duplicating
+// effort already exerted by the sniffer. If "freeMeta" is given, it will be
+// called against the opaque object when it is no longer used.
+typedef CreatorFunc (*SnifferFunc)(
+ DataSourceBase *source, float *confidence,
+ void **meta, FreeMetaFunc *freeMeta);
+
+typedef struct {
+ const uint8_t b[16];
+} media_uuid_t;
+
+typedef struct {
+ // version number of this structure
+ const uint32_t def_version;
+
+ // A unique identifier for this extractor.
+ // See below for a convenience macro to create this from a string.
+ media_uuid_t extractor_uuid;
+
+ // Version number of this extractor. When two extractors with the same
+ // uuid are encountered, the one with the largest version number will
+ // be used.
+ const uint32_t extractor_version;
+
+ // a human readable name
+ const char *extractor_name;
+
+ // the sniffer function
+ const SnifferFunc sniff;
+} ExtractorDef;
+
+const uint32_t EXTRACTORDEF_VERSION = 1;
+
+// each plugin library exports one function of this type
+typedef ExtractorDef (*GetExtractorDef)();
+
+} // extern "C"
+
+} // namespace android
+
+#endif // MEDIA_EXTRACTOR_PLUGIN_API_H_