dep: Add cubeb

dep/cubeb/src/android/cubeb_media_library.h

@@ -0,0 +1,62 @@
+#ifndef _CUBEB_MEDIA_LIBRARY_H_
+#define _CUBEB_MEDIA_LIBRARY_H_
+
+struct media_lib {
+  void * libmedia;
+  int32_t (* get_output_latency)(uint32_t * latency, int stream_type);
+};
+
+typedef struct media_lib media_lib;
+
+media_lib *
+cubeb_load_media_library()
+{
+  media_lib ml = {0};
+  ml.libmedia = dlopen("libmedia.so", RTLD_LAZY);
+  if (!ml.libmedia) {
+    return NULL;
+  }
+
+  // Get the latency, in ms, from AudioFlinger. First, try the most recent signature.
+  // status_t AudioSystem::getOutputLatency(uint32_t* latency, audio_stream_type_t streamType)
+  ml.get_output_latency =
+    dlsym(ml.libmedia, "_ZN7android11AudioSystem16getOutputLatencyEPj19audio_stream_type_t");
+  if (!ml.get_output_latency) {
+    // In case of failure, try the signature from legacy version.
+    // status_t AudioSystem::getOutputLatency(uint32_t* latency, int streamType)
+    ml.get_output_latency =
+      dlsym(ml.libmedia, "_ZN7android11AudioSystem16getOutputLatencyEPji");
+    if (!ml.get_output_latency) {
+      return NULL;
+    }
+  }
+
+  media_lib * rv = NULL;
+  rv = calloc(1, sizeof(media_lib));
+  assert(rv);
+  *rv = ml;
+  return rv;
+}
+
+void
+cubeb_close_media_library(media_lib * ml)
+{
+  dlclose(ml->libmedia);
+  ml->libmedia = NULL;
+  ml->get_output_latency = NULL;
+  free(ml);
+}
+
+uint32_t
+cubeb_get_output_latency_from_media_library(media_lib * ml)
+{
+  uint32_t latency = 0;
+  const int audio_stream_type_music = 3;
+  int32_t r = ml->get_output_latency(&latency, audio_stream_type_music);
+  if (r) {
+    return 0;
+  }
+  return latency;
+}
+
+#endif // _CUBEB_MEDIA_LIBRARY_H_