amc: Use new JNI utils almost everywhere

2 files changed, 177 insertions, 526 deletions

diff --git a/sys/androidmedia/gstamc.c b/sys/androidmedia/gstamc.c
index 1f45f31bf..dd41ad520 100644
--- a/sys/androidmedia/gstamc.c
+++ b/sys/androidmedia/gstamc.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2012, Collabora Ltd.
  *   Author: Sebastian Dröge <sebastian.droege@collabora.co.uk>
+ * Copyright (C) 2015, Sebastian Dröge <sebastian@centricular.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -117,36 +118,29 @@ gst_amc_codec_new (const gchar * name, GError ** err)
 
   env = gst_amc_jni_get_env ();
 
-  name_str = (*env)->NewStringUTF (env, name);
-  if (name_str == NULL) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create Java String");
+  name_str = gst_amc_jni_string_from_gchar (env, err, FALSE, name);
+  if (!name_str) {
     goto error;
   }
 
   codec = g_slice_new0 (GstAmcCodec);
 
-  object =
-      (*env)->CallStaticObjectMethod (env, media_codec.klass,
-      media_codec.create_by_codec_name, name_str);
-  if ((*env)->ExceptionCheck (env) || !object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create codec '%s'", name);
+  if (!gst_amc_jni_call_static_object_method (env, err, media_codec.klass,
+          media_codec.create_by_codec_name, &object, name_str))
     goto error;
-  }
 
-  codec->object = (*env)->NewGlobalRef (env, object);
+  codec->object = gst_amc_jni_object_make_global (env, object);
+  object = NULL;
+
   if (!codec->object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create global codec reference");
+    gst_amc_jni_set_error (env, err, GST_LIBRARY_ERROR,
+        GST_LIBRARY_ERROR_SETTINGS, "Failed to create global codec reference");
     goto error;
   }
 
 done:
-  if (object)
-    (*env)->DeleteLocalRef (env, object);
   if (name_str)
-    (*env)->DeleteLocalRef (env, name_str);
+    gst_amc_jni_object_local_unref (env, name_str);
   name_str = NULL;
 
   return codec;
@@ -166,7 +160,7 @@ gst_amc_codec_free (GstAmcCodec * codec)
   g_return_if_fail (codec != NULL);
 
   env = gst_amc_jni_get_env ();
-  (*env)->DeleteGlobalRef (env, codec->object);
+  gst_amc_jni_object_unref (env, codec->object);
   g_slice_free (GstAmcCodec, codec);
 }
 
@@ -175,25 +169,13 @@ gst_amc_codec_configure (GstAmcCodec * codec, GstAmcFormat * format, gint flags,
     GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
   g_return_val_if_fail (format != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.configure,
-      format->object, NULL, NULL, flags);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_SETTINGS,
-        err, "Failed to configure codec");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.configure, format->object, NULL, NULL, flags);
 }
 
 GstAmcFormat *
@@ -207,27 +189,20 @@ gst_amc_codec_get_output_format (GstAmcCodec * codec, GError ** err)
 
   env = gst_amc_jni_get_env ();
 
-  object =
-      (*env)->CallObjectMethod (env, codec->object,
-      media_codec.get_output_format);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_SETTINGS,
-        err, "Failed to get output format");
+  if (!gst_amc_jni_call_object_method (env, err, codec->object,
+          media_codec.get_output_format, &object))
     goto done;
-  }
 
   ret = g_slice_new0 (GstAmcFormat);
 
-  ret->object = (*env)->NewGlobalRef (env, object);
+  ret->object = gst_amc_jni_object_make_global (env, object);
   if (!ret->object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_SETTINGS,
-        err, "Failed to create global format reference");
+    gst_amc_jni_set_error (env, err, GST_LIBRARY_ERROR,
+        GST_LIBRARY_ERROR_SETTINGS, "Failed to create global format reference");
     g_slice_free (GstAmcFormat, ret);
     ret = NULL;
   }
 
-  (*env)->DeleteLocalRef (env, object);
-
 done:
 
   return ret;
@@ -237,109 +212,48 @@ gboolean
 gst_amc_codec_start (GstAmcCodec * codec, GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.start);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to start codec");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.start);
 }
 
 gboolean
 gst_amc_codec_stop (GstAmcCodec * codec, GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.stop);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to stop codec");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.stop);
 }
 
 gboolean
 gst_amc_codec_flush (GstAmcCodec * codec, GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.flush);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to flush codec");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.flush);
 }
 
 gboolean
 gst_amc_codec_release (GstAmcCodec * codec, GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.release);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to release codec");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
-}
-
-void
-gst_amc_codec_free_buffers (GstAmcBuffer * buffers, gsize n_buffers)
-{
-  JNIEnv *env;
-  jsize i;
-
-  g_return_if_fail (buffers != NULL);
-
-  env = gst_amc_jni_get_env ();
-
-  for (i = 0; i < n_buffers; i++) {
-    if (buffers[i].object)
-      (*env)->DeleteGlobalRef (env, buffers[i].object);
-  }
-  g_free (buffers);
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.release);
 }
 
 GstAmcBuffer *
@@ -348,9 +262,7 @@ gst_amc_codec_get_output_buffers (GstAmcCodec * codec, gsize * n_buffers,
 {
   JNIEnv *env;
   jobject output_buffers = NULL;
-  jsize n_output_buffers;
   GstAmcBuffer *ret = NULL;
-  jsize i;
 
   g_return_val_if_fail (codec != NULL, NULL);
   g_return_val_if_fail (n_buffers != NULL, NULL);
@@ -358,64 +270,17 @@ gst_amc_codec_get_output_buffers (GstAmcCodec * codec, gsize * n_buffers,
   *n_buffers = 0;
   env = gst_amc_jni_get_env ();
 
-  output_buffers =
-      (*env)->CallObjectMethod (env, codec->object,
-      media_codec.get_output_buffers);
-  if ((*env)->ExceptionCheck (env) || !output_buffers) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get output buffers");
-    goto done;
-  }
-
-  n_output_buffers = (*env)->GetArrayLength (env, output_buffers);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get output buffers array length");
+  if (!gst_amc_jni_call_object_method (env, err, codec->object,
+          media_codec.get_output_buffers, &output_buffers))
     goto done;
-  }
-
-  *n_buffers = n_output_buffers;
-  ret = g_new0 (GstAmcBuffer, n_output_buffers);
-
-  for (i = 0; i < n_output_buffers; i++) {
-    jobject buffer = NULL;
 
-    buffer = (*env)->GetObjectArrayElement (env, output_buffers, i);
-    if ((*env)->ExceptionCheck (env) || !buffer) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to get output buffer %d", i);
-      goto error;
-    }
-
-    ret[i].object = (*env)->NewGlobalRef (env, buffer);
-    (*env)->DeleteLocalRef (env, buffer);
-    if (!ret[i].object) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to create global output buffer reference %d", i);
-      goto error;
-    }
-
-    ret[i].data = (*env)->GetDirectBufferAddress (env, ret[i].object);
-    if (!ret[i].data) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to get output buffer address %d", i);
-      goto error;
-    }
-    ret[i].size = (*env)->GetDirectBufferCapacity (env, ret[i].object);
-  }
+  gst_amc_jni_get_buffer_array (env, err, output_buffers, &ret, n_buffers);
 
 done:
   if (output_buffers)
-    (*env)->DeleteLocalRef (env, output_buffers);
-  output_buffers = NULL;
+    gst_amc_jni_object_local_unref (env, output_buffers);
 
   return ret;
-error:
-  if (ret)
-    gst_amc_codec_free_buffers (ret, n_output_buffers);
-  ret = NULL;
-  *n_buffers = 0;
-  goto done;
 }
 
 GstAmcBuffer *
@@ -424,9 +289,7 @@ gst_amc_codec_get_input_buffers (GstAmcCodec * codec, gsize * n_buffers,
 {
   JNIEnv *env;
   jobject input_buffers = NULL;
-  jsize n_input_buffers;
   GstAmcBuffer *ret = NULL;
-  jsize i;
 
   g_return_val_if_fail (codec != NULL, NULL);
   g_return_val_if_fail (n_buffers != NULL, NULL);
@@ -434,64 +297,26 @@ gst_amc_codec_get_input_buffers (GstAmcCodec * codec, gsize * n_buffers,
   *n_buffers = 0;
   env = gst_amc_jni_get_env ();
 
-  input_buffers =
-      (*env)->CallObjectMethod (env, codec->object,
-      media_codec.get_input_buffers);
-  if ((*env)->ExceptionCheck (env) || !input_buffers) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get input buffers");
+  if (!gst_amc_jni_call_object_method (env, err, codec->object,
+          media_codec.get_input_buffers, &input_buffers))
     goto done;
-  }
 
-  n_input_buffers = (*env)->GetArrayLength (env, input_buffers);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get input buffers array length");
-    goto done;
-  }
-
-  *n_buffers = n_input_buffers;
-  ret = g_new0 (GstAmcBuffer, n_input_buffers);
-
-  for (i = 0; i < n_input_buffers; i++) {
-    jobject buffer = NULL;
-
-    buffer = (*env)->GetObjectArrayElement (env, input_buffers, i);
-    if ((*env)->ExceptionCheck (env) || !buffer) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to get input buffer %d", i);
-      goto error;
-    }
-
-    ret[i].object = (*env)->NewGlobalRef (env, buffer);
-    (*env)->DeleteLocalRef (env, buffer);
-    if (!ret[i].object) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to create global input buffer reference %d", i);
-      goto error;
-    }
-
-    ret[i].data = (*env)->GetDirectBufferAddress (env, ret[i].object);
-    if (!ret[i].data) {
-      gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-          err, "Failed to get input buffer address %d", i);
-      goto error;
-    }
-    ret[i].size = (*env)->GetDirectBufferCapacity (env, ret[i].object);
-  }
+  gst_amc_jni_get_buffer_array (env, err, input_buffers, &ret, n_buffers);
 
 done:
   if (input_buffers)
-    (*env)->DeleteLocalRef (env, input_buffers);
-  input_buffers = NULL;
+    gst_amc_jni_object_local_unref (env, input_buffers);
 
   return ret;
-error:
-  if (ret)
-    gst_amc_codec_free_buffers (ret, n_input_buffers);
-  ret = NULL;
-  *n_buffers = 0;
-  goto done;
+}
+
+void
+gst_amc_codec_free_buffers (GstAmcBuffer * buffers, gsize n_buffers)
+{
+  JNIEnv *env;
+
+  env = gst_amc_jni_get_env ();
+  gst_amc_jni_free_buffer_array (env, buffers, n_buffers);
 }
 
 gint
@@ -504,18 +329,9 @@ gst_amc_codec_dequeue_input_buffer (GstAmcCodec * codec, gint64 timeoutUs,
   g_return_val_if_fail (codec != NULL, G_MININT);
 
   env = gst_amc_jni_get_env ();
-
-  ret =
-      (*env)->CallIntMethod (env, codec->object,
-      media_codec.dequeue_input_buffer, timeoutUs);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to dequeue input buffer");
-    ret = G_MININT;
-    goto done;
-  }
-
-done:
+  if (!gst_amc_jni_call_int_method (env, err, codec->object,
+          media_codec.dequeue_input_buffer, &ret, timeoutUs))
+    return G_MININT;
 
   return ret;
 }
@@ -526,39 +342,22 @@ gst_amc_codec_fill_buffer_info (JNIEnv * env, jobject buffer_info,
 {
   g_return_val_if_fail (buffer_info != NULL, FALSE);
 
-  info->flags =
-      (*env)->GetIntField (env, buffer_info, media_codec_buffer_info.flags);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get buffer info flags");
+  if (!gst_amc_jni_get_int_field (env, err, buffer_info,
+          media_codec_buffer_info.flags, &info->flags))
     return FALSE;
-  }
 
-  info->offset =
-      (*env)->GetIntField (env, buffer_info, media_codec_buffer_info.offset);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get buffer info offset");
+  if (!gst_amc_jni_get_int_field (env, err, buffer_info,
+          media_codec_buffer_info.offset, &info->offset))
     return FALSE;
-  }
 
-  info->presentation_time_us =
-      (*env)->GetLongField (env, buffer_info,
-      media_codec_buffer_info.presentation_time_us);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get buffer info pts");
+  if (!gst_amc_jni_get_long_field (env, err, buffer_info,
+          media_codec_buffer_info.presentation_time_us,
+          &info->presentation_time_us))
     return FALSE;
-  }
 
-  info->size =
-      (*env)->GetIntField (env, buffer_info, media_codec_buffer_info.size);
-  if ((*env)->ExceptionCheck (env)) {
-    (*env)->ExceptionClear (env);
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get buffer info size");
+  if (!gst_amc_jni_get_int_field (env, err, buffer_info,
+          media_codec_buffer_info.size, &info->size))
     return FALSE;
-  }
 
   return TRUE;
 }
@@ -576,20 +375,13 @@ gst_amc_codec_dequeue_output_buffer (GstAmcCodec * codec,
   env = gst_amc_jni_get_env ();
 
   info_o =
-      (*env)->NewObject (env, media_codec_buffer_info.klass,
+      gst_amc_jni_new_object (env, err, FALSE, media_codec_buffer_info.klass,
       media_codec_buffer_info.constructor);
-  if (!info_o) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create buffer info instance");
+  if (!info_o)
     goto done;
-  }
 
-  ret =
-      (*env)->CallIntMethod (env, codec->object,
-      media_codec.dequeue_output_buffer, info_o, timeoutUs);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to dequeue output buffer");
+  if (!gst_amc_jni_call_int_method (env, err, codec->object,
+          media_codec.dequeue_output_buffer, &ret, info_o, timeoutUs)) {
     ret = G_MININT;
     goto done;
   }
@@ -601,7 +393,7 @@ gst_amc_codec_dequeue_output_buffer (GstAmcCodec * codec,
 
 done:
   if (info_o)
-    (*env)->DeleteLocalRef (env, info_o);
+    gst_amc_jni_object_local_unref (env, info_o);
   info_o = NULL;
 
   return ret;
@@ -612,25 +404,14 @@ gst_amc_codec_queue_input_buffer (GstAmcCodec * codec, gint index,
     const GstAmcBufferInfo * info, GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
   g_return_val_if_fail (info != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.queue_input_buffer,
-      index, info->offset, info->size, info->presentation_time_us, info->flags);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to queue input buffer");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.queue_input_buffer, index, info->offset, info->size,
+      info->presentation_time_us, info->flags);
 }
 
 gboolean
@@ -638,24 +419,12 @@ gst_amc_codec_release_output_buffer (GstAmcCodec * codec, gint index,
     GError ** err)
 {
   JNIEnv *env;
-  gboolean ret = TRUE;
 
   g_return_val_if_fail (codec != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
-
-  (*env)->CallVoidMethod (env, codec->object, media_codec.release_output_buffer,
-      index, JNI_FALSE);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to release output buffer");
-    ret = FALSE;
-    goto done;
-  }
-
-done:
-
-  return ret;
+  return gst_amc_jni_call_void_method (env, err, codec->object,
+      media_codec.release_output_buffer, index, JNI_FALSE);
 }
 
 GstAmcFormat *
@@ -665,42 +434,25 @@ gst_amc_format_new_audio (const gchar * mime, gint sample_rate, gint channels,
   JNIEnv *env;
   GstAmcFormat *format = NULL;
   jstring mime_str;
-  jobject object = NULL;
 
   g_return_val_if_fail (mime != NULL, NULL);
 
   env = gst_amc_jni_get_env ();
 
-  mime_str = (*env)->NewStringUTF (env, mime);
-  if (mime_str == NULL) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create Java string");
+  mime_str = gst_amc_jni_string_from_gchar (env, err, FALSE, mime);
+  if (!mime_str)
     goto error;
-  }
 
   format = g_slice_new0 (GstAmcFormat);
-
-  object =
-      (*env)->CallStaticObjectMethod (env, media_format.klass,
+  format->object =
+      gst_amc_jni_new_object_from_static (env, err, TRUE, media_format.klass,
       media_format.create_audio_format, mime_str, sample_rate, channels);
-  if ((*env)->ExceptionCheck (env) || !object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create format instance '%s'", mime);
+  if (!format->object)
     goto error;
-  }
-
-  format->object = (*env)->NewGlobalRef (env, object);
-  if (!format->object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create global format reference");
-    goto error;
-  }
 
 done:
-  if (object)
-    (*env)->DeleteLocalRef (env, object);
   if (mime_str)
-    (*env)->DeleteLocalRef (env, mime_str);
+    gst_amc_jni_object_local_unref (env, mime_str);
   mime_str = NULL;
 
   return format;
@@ -719,42 +471,25 @@ gst_amc_format_new_video (const gchar * mime, gint width, gint height,
   JNIEnv *env;
   GstAmcFormat *format = NULL;
   jstring mime_str;
-  jobject object = NULL;
 
   g_return_val_if_fail (mime != NULL, NULL);
 
   env = gst_amc_jni_get_env ();
 
-  mime_str = (*env)->NewStringUTF (env, mime);
-  if (mime_str == NULL) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create Java string");
+  mime_str = gst_amc_jni_string_from_gchar (env, err, FALSE, mime);
+  if (!mime_str)
     goto error;
-  }
 
   format = g_slice_new0 (GstAmcFormat);
-
-  object =
-      (*env)->CallStaticObjectMethod (env, media_format.klass,
+  format->object =
+      gst_amc_jni_new_object_from_static (env, err, TRUE, media_format.klass,
       media_format.create_video_format, mime_str, width, height);
-  if ((*env)->ExceptionCheck (env) || !object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create format instance '%s'", mime);
-    goto error;
-  }
-
-  format->object = (*env)->NewGlobalRef (env, object);
-  if (!format->object) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_INIT, err,
-        "Failed to create global format reference");
+  if (!format->object)
     goto error;
-  }
 
 done:
-  if (object)
-    (*env)->DeleteLocalRef (env, object);
   if (mime_str)
-    (*env)->DeleteLocalRef (env, mime_str);
+    gst_amc_jni_object_local_unref (env, mime_str);
   mime_str = NULL;
 
   return format;
@@ -774,7 +509,7 @@ gst_amc_format_free (GstAmcFormat * format)
   g_return_if_fail (format != NULL);
 
   env = gst_amc_jni_get_env ();
-  (*env)->DeleteGlobalRef (env, format->object);
+  gst_amc_jni_object_unref (env, format->object);
   g_slice_free (GstAmcFormat, format);
 }
 
@@ -783,35 +518,18 @@ gst_amc_format_to_string (GstAmcFormat * format, GError ** err)
 {
   JNIEnv *env;
   jstring v_str = NULL;
-  const gchar *v = NULL;
   gchar *ret = NULL;
 
   g_return_val_if_fail (format != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
 
-  v_str =
-      (*env)->CallObjectMethod (env, format->object, media_format.to_string);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to convert format to string");
+  if (!gst_amc_jni_call_object_method (env, err, format->object,
+          media_format.to_string, &v_str))
     goto done;
-  }
-
-  v = (*env)->GetStringUTFChars (env, v_str, NULL);
-  if (!v) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to get UTF8 string");
-    goto done;
-  }
-
-  ret = g_strdup (v);
+  ret = gst_amc_jni_string_to_gchar (env, v_str, TRUE);
 
 done:
-  if (v)
-    (*env)->ReleaseStringUTFChars (env, v_str, v);
-  if (v_str)
-    (*env)->DeleteLocalRef (env, v_str);
 
   return ret;
 }
@@ -829,25 +547,17 @@ gst_amc_format_contains_key (GstAmcFormat * format, const gchar * key,
 
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  ret =
-      (*env)->CallBooleanMethod (env, format->object, media_format.contains_key,
-      key_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to check if format contains key '%s'", key);
+  if (!gst_amc_jni_call_boolean_method (env, err, format->object,
+          media_format.contains_key, &ret, key_str))
     goto done;
-  }
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
 
   return ret;
 }
@@ -867,60 +577,50 @@ gst_amc_format_get_float (GstAmcFormat * format, const gchar * key,
   *value = 0;
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  *value =
-      (*env)->CallFloatMethod (env, format->object, media_format.get_float,
-      key_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get float key '%s'", key);
+  if (!gst_amc_jni_call_float_method (env, err, format->object,
+          media_format.get_float, value, key_str))
     goto done;
-  }
   ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
 
   return ret;
 }
 
-void
+gboolean
 gst_amc_format_set_float (GstAmcFormat * format, const gchar * key,
     gfloat value, GError ** err)
 {
   JNIEnv *env;
   jstring key_str = NULL;
+  gboolean ret = FALSE;
 
-  g_return_if_fail (format != NULL);
-  g_return_if_fail (key != NULL);
+  g_return_val_if_fail (format != NULL, FALSE);
+  g_return_val_if_fail (key != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  (*env)->CallVoidMethod (env, format->object, media_format.set_float, key_str,
-      value);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed set float key '%s'", key);
+  if (!gst_amc_jni_call_void_method (env, err, format->object,
+          media_format.set_float, key_str, value))
     goto done;
-  }
+
+  ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
+
+  return ret;
 }
 
 gboolean
@@ -938,61 +638,51 @@ gst_amc_format_get_int (GstAmcFormat * format, const gchar * key, gint * value,
   *value = 0;
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  *value =
-      (*env)->CallIntMethod (env, format->object, media_format.get_integer,
-      key_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get integer key '%s'", key);
+  if (!gst_amc_jni_call_int_method (env, err, format->object,
+          media_format.get_integer, value, key_str))
     goto done;
-  }
   ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
 
   return ret;
 
 }
 
-void
+gboolean
 gst_amc_format_set_int (GstAmcFormat * format, const gchar * key, gint value,
     GError ** err)
 {
   JNIEnv *env;
   jstring key_str = NULL;
+  gboolean ret = FALSE;
 
-  g_return_if_fail (format != NULL);
-  g_return_if_fail (key != NULL);
+  g_return_val_if_fail (format != NULL, FALSE);
+  g_return_val_if_fail (key != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  (*env)->CallVoidMethod (env, format->object, media_format.set_integer,
-      key_str, value);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed set integer key '%s'", key);
+  if (!gst_amc_jni_call_void_method (env, err, format->object,
+          media_format.set_integer, key_str, value))
     goto done;
-  }
+
+  ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
+
+  return ret;
 }
 
 gboolean
@@ -1003,7 +693,6 @@ gst_amc_format_get_string (GstAmcFormat * format, const gchar * key,
   gboolean ret = FALSE;
   jstring key_str = NULL;
   jstring v_str = NULL;
-  const gchar *v = NULL;
 
   g_return_val_if_fail (format != NULL, FALSE);
   g_return_val_if_fail (key != NULL, FALSE);
@@ -1012,85 +701,61 @@ gst_amc_format_get_string (GstAmcFormat * format, const gchar * key,
   *value = 0;
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  v_str =
-      (*env)->CallObjectMethod (env, format->object, media_format.get_string,
-      key_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get string key '%s'", key);
+  if (!gst_amc_jni_call_object_method (env, err, format->object,
+          media_format.get_string, &v_str, key_str))
     goto done;
-  }
 
-  v = (*env)->GetStringUTFChars (env, v_str, NULL);
-  if (!v) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get string UTF8 characters");
-    goto done;
-  }
-
-  *value = g_strdup (v);
+  *value = gst_amc_jni_string_to_gchar (env, v_str, TRUE);
 
   ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
-  if (v)
-    (*env)->ReleaseStringUTFChars (env, v_str, v);
-  if (v_str)
-    (*env)->DeleteLocalRef (env, v_str);
+    gst_amc_jni_object_local_unref (env, key_str);
 
   return ret;
 }
 
-void
+gboolean
 gst_amc_format_set_string (GstAmcFormat * format, const gchar * key,
     const gchar * value, GError ** err)
 {
   JNIEnv *env;
   jstring key_str = NULL;
   jstring v_str = NULL;
+  gboolean ret = FALSE;
 
-  g_return_if_fail (format != NULL);
-  g_return_if_fail (key != NULL);
-  g_return_if_fail (value != NULL);
+  g_return_val_if_fail (format != NULL, FALSE);
+  g_return_val_if_fail (key != NULL, FALSE);
+  g_return_val_if_fail (value != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  v_str = (*env)->NewStringUTF (env, value);
-  if (!v_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  v_str = gst_amc_jni_string_from_gchar (env, err, FALSE, value);
+  if (!v_str)
     goto done;
-  }
 
-  (*env)->CallVoidMethod (env, format->object, media_format.set_string, key_str,
-      v_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed set string key '%s'", key);
+  if (!gst_amc_jni_call_void_method (env, err, format->object,
+          media_format.set_string, key_str, v_str))
     goto done;
-  }
+
+  ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
   if (v_str)
-    (*env)->DeleteLocalRef (env, v_str);
+    gst_amc_jni_object_local_unref (env, v_str);
+
+  return ret;
 }
 
 gboolean
@@ -1111,25 +776,18 @@ gst_amc_format_get_buffer (GstAmcFormat * format, const gchar * key,
   *size = 0;
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
-  v = (*env)->CallObjectMethod (env, format->object,
-      media_format.get_byte_buffer, key_str);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get buffer key '%s'", key);
+  if (!gst_amc_jni_call_object_method (env, err, format->object,
+          media_format.get_byte_buffer, &v, key_str))
     goto done;
-  }
 
   *data = (*env)->GetDirectBufferAddress (env, v);
   if (!data) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed get buffer address");
+    gst_amc_jni_set_error (env, err, GST_LIBRARY_ERROR,
+        GST_LIBRARY_ERROR_FAILED, "Failed get buffer address");
     goto done;
   }
   *size = (*env)->GetDirectBufferCapacity (env, v);
@@ -1139,55 +797,53 @@ gst_amc_format_get_buffer (GstAmcFormat * format, const gchar * key,
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
   if (v)
-    (*env)->DeleteLocalRef (env, v);
+    gst_amc_jni_object_local_unref (env, v);
 
   return ret;
 }
 
-void
+gboolean
 gst_amc_format_set_buffer (GstAmcFormat * format, const gchar * key,
     guint8 * data, gsize size, GError ** err)
 {
   JNIEnv *env;
   jstring key_str = NULL;
   jobject v = NULL;
+  gboolean ret = FALSE;
 
-  g_return_if_fail (format != NULL);
-  g_return_if_fail (key != NULL);
-  g_return_if_fail (data != NULL);
+  g_return_val_if_fail (format != NULL, FALSE);
+  g_return_val_if_fail (key != NULL, FALSE);
+  g_return_val_if_fail (data != NULL, FALSE);
 
   env = gst_amc_jni_get_env ();
 
-  key_str = (*env)->NewStringUTF (env, key);
-  if (!key_str) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed to create Java string");
+  key_str = gst_amc_jni_string_from_gchar (env, err, FALSE, key);
+  if (!key_str)
     goto done;
-  }
 
   /* FIXME: The memory must remain valid until the codec is stopped */
   v = (*env)->NewDirectByteBuffer (env, data, size);
   if (!v) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed create Java byte buffer");
+    gst_amc_jni_set_error (env, err, GST_LIBRARY_ERROR,
+        GST_LIBRARY_ERROR_FAILED, "Failed create Java byte buffer");
     goto done;
   }
 
-  (*env)->CallVoidMethod (env, format->object, media_format.set_byte_buffer,
-      key_str, v);
-  if ((*env)->ExceptionCheck (env)) {
-    gst_amc_jni_set_error (env, GST_LIBRARY_ERROR, GST_LIBRARY_ERROR_FAILED,
-        err, "Failed set buffer key '%s'", key);
+  if (!gst_amc_jni_call_void_method (env, err, format->object,
+          media_format.set_byte_buffer, key_str, v))
     goto done;
-  }
+
+  ret = TRUE;
 
 done:
   if (key_str)
-    (*env)->DeleteLocalRef (env, key_str);
+    gst_amc_jni_object_local_unref (env, key_str);
   if (v)
-    (*env)->DeleteLocalRef (env, v);
+    gst_amc_jni_object_local_unref (env, v);
+
+  return ret;
 }
 
 static gboolean
diff --git a/sys/androidmedia/gstamc.h b/sys/androidmedia/gstamc.h
index 7fcae1e56..e216039bd 100644
--- a/sys/androidmedia/gstamc.h
+++ b/sys/androidmedia/gstamc.h
@@ -26,6 +26,8 @@
 #include <gst/audio/audio.h>
 #include <jni.h>
 
+#include "gstjniutils.h"
+
 G_BEGIN_DECLS
 
 typedef struct _GstAmcCodecInfo GstAmcCodecInfo;
@@ -33,7 +35,6 @@ typedef struct _GstAmcCodecType GstAmcCodecType;
 typedef struct _GstAmcCodec GstAmcCodec;
 typedef struct _GstAmcBufferInfo GstAmcBufferInfo;
 typedef struct _GstAmcFormat GstAmcFormat;
-typedef struct _GstAmcBuffer GstAmcBuffer;
 typedef struct _GstAmcColorFormatInfo GstAmcColorFormatInfo;
 
 struct _GstAmcCodecType {
@@ -56,12 +57,6 @@ struct _GstAmcCodecInfo {
   gint n_supported_types;
 };
 
-struct _GstAmcBuffer {
-  jobject object; /* global reference */
-  guint8 *data;
-  gsize size;
-};
-
 struct _GstAmcFormat {
   /* < private > */
   jobject object; /* global reference */
@@ -112,13 +107,13 @@ gchar * gst_amc_format_to_string (GstAmcFormat * format, GError **err);
 gboolean gst_amc_format_contains_key (GstAmcFormat *format, const gchar *key, GError **err);
 
 gboolean gst_amc_format_get_float (GstAmcFormat *format, const gchar *key, gfloat *value, GError **err);
-void gst_amc_format_set_float (GstAmcFormat *format, const gchar *key, gfloat value, GError **err);
+gboolean gst_amc_format_set_float (GstAmcFormat *format, const gchar *key, gfloat value, GError **err);
 gboolean gst_amc_format_get_int (GstAmcFormat *format, const gchar *key, gint *value, GError **err);
-void gst_amc_format_set_int (GstAmcFormat *format, const gchar *key, gint value, GError **err);
+gboolean gst_amc_format_set_int (GstAmcFormat *format, const gchar *key, gint value, GError **err);
 gboolean gst_amc_format_get_string (GstAmcFormat *format, const gchar *key, gchar **value, GError **err);
-void gst_amc_format_set_string (GstAmcFormat *format, const gchar *key, const gchar *value, GError **err);
+gboolean gst_amc_format_set_string (GstAmcFormat *format, const gchar *key, const gchar *value, GError **err);
 gboolean gst_amc_format_get_buffer (GstAmcFormat *format, const gchar *key, guint8 **data, gsize *size, GError **err);
-void gst_amc_format_set_buffer (GstAmcFormat *format, const gchar *key, guint8 *data, gsize size, GError **err);
+gboolean gst_amc_format_set_buffer (GstAmcFormat *format, const gchar *key, guint8 *data, gsize size, GError **err);
 
 GstVideoFormat gst_amc_color_format_to_video_format (const GstAmcCodecInfo * codec_info, const gchar * mime, gint color_format);
 gint gst_amc_video_format_to_color_format (const GstAmcCodecInfo * codec_info, const gchar * mime, GstVideoFormat video_format);