Create GStreamer plugin from Rust and have the plugin entry point written in Rust

build.rs

@@ -23,7 +23,7 @@ fn main() {
     let gstbase = pkg_config::probe_library("gstreamer-base-1.0").unwrap();
     let includes = [gstreamer.include_paths, gstbase.include_paths];
 
-    let files = ["src/plugin.c", "src/rssource.c", "src/rssink.c", "src/rsdemuxer.c"];
+    let files = ["src/lib.c", "src/rssource.c", "src/rssink.c", "src/rsdemuxer.c"];
 
     let mut config = gcc::Config::new();
     config.include("src");

src/lib.c

@@ -22,32 +22,6 @@
 #include "rssink.h"
 #include "rsdemuxer.h"
 
-static gboolean
-plugin_init (GstPlugin * plugin)
-{
-  if (!gst_rs_source_plugin_init (plugin))
-    return FALSE;
-
-  if (!gst_rs_sink_plugin_init (plugin))
-    return FALSE;
-
-  if (!gst_rs_demuxer_plugin_init (plugin))
-    return FALSE;
-
-  return TRUE;
-}
-
-#define VERSION "1.0"
-#define PACKAGE "rsplugin"
-#define GST_PACKAGE_NAME PACKAGE
-#define GST_PACKAGE_ORIGIN "http://www.example.org"
-
-GST_PLUGIN_DEFINE (GST_VERSION_MAJOR,
-    GST_VERSION_MINOR,
-    rsplugin,
-    "Rust Plugin", plugin_init, VERSION, "LGPL", GST_PACKAGE_NAME,
-    GST_PACKAGE_ORIGIN);
-
 void
 gst_rs_element_error (GstElement * element, GQuark error_domain,
     gint error_code, const gchar * message, const gchar * debug,

src/lib.rs

@@ -96,8 +96,7 @@ unsafe fn source_register(plugin: *const c_void,
 
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn sources_register(plugin: *const c_void) -> GBoolean {
+unsafe fn sources_register(plugin: *const c_void) -> GBoolean {
     source_register(plugin,
                     "rsfilesrc",
                     "File Source",
@@ -163,8 +162,7 @@ unsafe fn sink_register(plugin: *const c_void,
                          cprotocols.as_ptr());
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn sinks_register(plugin: *const c_void) -> GBoolean {
+unsafe fn sinks_register(plugin: *const c_void) -> GBoolean {
     sink_register(plugin,
                   "rsfilesink",
                   "File Sink",
@@ -222,8 +220,7 @@ unsafe fn demuxer_register(plugin: *const c_void,
                             coutput_formats.as_ptr());
 }
 
-#[no_mangle]
-pub unsafe extern "C" fn demuxers_register(plugin: *const c_void) -> GBoolean {
+unsafe fn demuxers_register(plugin: *const c_void) -> GBoolean {
     demuxer_register(plugin,
                      "rsflvdemux",
                      "FLV Demuxer",
@@ -237,3 +234,48 @@ pub unsafe extern "C" fn demuxers_register(plugin: *const c_void) -> GBoolean {
 
     GBoolean::True
 }
+
+#[repr(C)]
+pub struct GstPluginDesc {
+    major_version: i32,
+    minor_version: i32,
+    name: *const u8,
+    description: *const u8,
+    plugin_init: extern "C" fn(plugin: *const c_void) -> GBoolean,
+    version: *const u8,
+    license: *const u8,
+    source: *const u8,
+    package: *const u8,
+    origin: *const u8,
+    release_datetime: *const u8,
+    _gst_reserved: [usize; 4],
+}
+
+unsafe impl Sync for GstPluginDesc {}
+
+extern "C" fn plugin_init(plugin: *const c_void) -> GBoolean {
+    unsafe {
+        sources_register(plugin);
+        sinks_register(plugin);
+        demuxers_register(plugin);
+    }
+
+    GBoolean::True
+}
+
+#[no_mangle]
+#[allow(non_upper_case_globals)]
+pub static gst_plugin_desc: GstPluginDesc = GstPluginDesc {
+    major_version: 1,
+    minor_version: 10,
+    name: b"rsplugin\0" as *const u8,
+    description: b"Rust Plugin\0" as *const u8,
+    plugin_init: plugin_init,
+    version: b"1.0\0" as *const u8,
+    license: b"LGPL\0" as *const u8,
+    source: b"rsplugin\0" as *const u8,
+    package: b"rsplugin\0" as *const u8,
+    origin: b"https://github.com/sdroege/rsplugin\0" as *const u8,
+    release_datetime: b"2016-12-08\0" as *const u8,
+    _gst_reserved: [0, 0, 0, 0],
+};

src/rsdemuxer.c

@@ -470,16 +470,14 @@ gst_rs_demuxer_remove_all_streams (GstRsDemuxer * demuxer)
   memset (demuxer->srcpads, 0, sizeof (demuxer->srcpads));
 }
 
-gboolean
-gst_rs_demuxer_plugin_init (GstPlugin * plugin)
+static gpointer
+gst_rs_demuxer_init_class (gpointer data)
 {
   demuxers = g_hash_table_new (g_direct_hash, g_direct_equal);
   GST_DEBUG_CATEGORY_INIT (gst_rs_demuxer_debug, "rsdemux", 0,
       "rsdemux element");
 
   parent_class = g_type_class_ref (GST_TYPE_ELEMENT);
-
-  return demuxers_register (plugin);
 }
 
 gboolean
@@ -489,6 +487,7 @@ gst_rs_demuxer_register (GstPlugin * plugin, const gchar * name,
     void *create_instance, const gchar * input_format,
     const gchar * output_formats)
 {
+  GOnce gonce = G_ONCE_INIT;
   GTypeInfo type_info = {
     sizeof (GstRsDemuxerClass),
     NULL,
@@ -504,6 +503,8 @@ gst_rs_demuxer_register (GstPlugin * plugin, const gchar * name,
   gchar *type_name;
   ElementData *data;
 
+  g_once (&gonce, gst_rs_demuxer_init_class, NULL);
+
   data = g_new0 (ElementData, 1);
   data->long_name = g_strdup (long_name);
   data->description = g_strdup (description);

src/rssink.c

@@ -243,15 +243,13 @@ gst_rs_sink_uri_handler_init (gpointer g_iface, gpointer iface_data)
   iface->set_uri = gst_rs_sink_uri_set_uri;
 }
 
-gboolean
-gst_rs_sink_plugin_init (GstPlugin * plugin)
+static gpointer
+gst_rs_sink_init_class (gpointer data)
 {
   sinks = g_hash_table_new (g_direct_hash, g_direct_equal);
   GST_DEBUG_CATEGORY_INIT (gst_rs_sink_debug, "rssink", 0, "rssink element");
 
   parent_class = g_type_class_ref (GST_TYPE_BASE_SINK);
-
-  return sinks_register (plugin);
 }
 
 gboolean
@@ -260,6 +258,7 @@ gst_rs_sink_register (GstPlugin * plugin, const gchar * name,
     const gchar * classification, const gchar * author, GstRank rank,
     void *create_instance, const gchar * protocols)
 {
+  static GOnce gonce = G_ONCE_INIT;
   GTypeInfo type_info = {
     sizeof (GstRsSinkClass),
     NULL,
@@ -280,6 +279,8 @@ gst_rs_sink_register (GstPlugin * plugin, const gchar * name,
   gchar *type_name;
   ElementData *data;
 
+  g_once (&gonce, gst_rs_sink_init_class, NULL);
+
   data = g_new0 (ElementData, 1);
   data->name = g_strdup (name);
   data->long_name = g_strdup (long_name);

src/rssource.c

@@ -280,15 +280,15 @@ gst_rs_src_uri_handler_init (gpointer g_iface, gpointer iface_data)
   iface->set_uri = gst_rs_src_uri_set_uri;
 }
 
-gboolean
-gst_rs_source_plugin_init (GstPlugin * plugin)
+static gpointer
+gst_rs_source_init_class (gpointer data)
 {
   sources = g_hash_table_new (g_direct_hash, g_direct_equal);
   GST_DEBUG_CATEGORY_INIT (gst_rs_src_debug, "rssrc", 0, "rssrc element");
 
   parent_class = g_type_class_ref (GST_TYPE_BASE_SRC);
 
-  return sources_register (plugin);
+  return NULL;
 }
 
 gboolean
@@ -297,6 +297,7 @@ gst_rs_source_register (GstPlugin * plugin, const gchar * name,
     const gchar * classification, const gchar * author, GstRank rank,
     void *create_instance, const gchar * protocols, gboolean push_only)
 {
+  static GOnce gonce = G_ONCE_INIT;
   GTypeInfo type_info = {
     sizeof (GstRsSrcClass),
     NULL,
@@ -317,6 +318,8 @@ gst_rs_source_register (GstPlugin * plugin, const gchar * name,
   gchar *type_name;
   ElementData *data;
 
+  g_once (&gonce, gst_rs_source_init_class, NULL);
+
   data = g_new0 (ElementData, 1);
   data->long_name = g_strdup (long_name);
   data->description = g_strdup (description);