feat: generate gstreamer registry if gst-launch-1.0 is present

closes #158

appimagebuilder/modules/setup/helpers/gstreamer.py

@@ -9,7 +9,10 @@
 #
 #  The above copyright notice and this permission notice shall be included in
 #  all copies or substantial portions of the Software.
+import logging
 import os
+import shutil
+import subprocess
 
 from appimagebuilder.utils.finder import Finder
 from .base_helper import BaseHelper
@@ -21,6 +24,7 @@ def configure(self, env: Environment):
         self._set_gst_plugins_path(env)
         self._set_gst_plugins_scanner_path(env)
         self._set_ptp_helper_path(env)
+        self._generate_gst_registry(env)
 
     def _set_gst_plugins_path(self, env):
         gst_1_lib_path = self.finder.find_one(
@@ -47,3 +51,32 @@ def _set_ptp_helper_path(self, app_run):
         )
         if gst_ptp_helper_path:
             app_run.set("GST_PTP_HELPER", gst_ptp_helper_path)
+
+    def _generate_gst_registry(self, env):
+        gst_launch_bin = shutil.which("gst-launch-1.0")
+        if gst_launch_bin and "GST_PLUGIN_PATH" in env:
+            env.set("GST_REGISTRY", env["GST_PLUGIN_PATH"] + "/registry.bin")
+
+            gst_launch_env = self._prepare_gst_launch_env(env)
+            # run gst "diagnostic" to force registry generation
+            # https://gstreamer.freedesktop.org/documentation/tools/gst-launch.html?gi-language=c#diagnostic
+            proc = subprocess.run(
+                [gst_launch_bin, "fakesrc", "num-buffers=16", "!", "fakesink"],
+                env=gst_launch_env,
+            )
+            if proc.returncode == 0:
+                env.set("GST_REGISTRY_UPDATE", "no")
+                logging.info(f"GST_REGISTRY generated at: {env['GST_REGISTRY']}")
+            else:
+                logging.warning(f"GST_REGISTRY generation failed!")
+                del env["GST_REGISTRY"]
+        else:
+            logging.warning(f"gst-launch-1.0 not found! It is required to generate gstreamer registry")
+
+    def _prepare_gst_launch_env(self, env):
+        gst_launch_env = os.environ
+        for key in env.keys():
+            if key.startswith("GST"):
+                gst_launch_env[key] = env[key].__str__()
+
+        return gst_launch_env