From c63b2f2712541c2e79233e96f6060c762766e54c Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Date: Wed, 12 May 2021 17:32:20 -0400
Subject: [PATCH] alphadecodebin: Use normal queues instead of multiqueue

The multiqueue was too flexible for our need, allowing to queue passed
the configured threshold. It also didn't work well when trying to
propagate EOS flow return.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2238>
---
 gst/codecalpha/gstalphadecodebin.c | 46 ++++++++++++------------------
 1 file changed, 18 insertions(+), 28 deletions(-)

diff --git a/gst/codecalpha/gstalphadecodebin.c b/gst/codecalpha/gstalphadecodebin.c
index aead165893..9f0a0a3f1c 100644
--- a/gst/codecalpha/gstalphadecodebin.c
+++ b/gst/codecalpha/gstalphadecodebin.c
@@ -97,7 +97,8 @@ gst_alpha_decode_bin_constructed (GObject * obj)
   GstPad *src_gpad, *sink_gpad;
   GstPad *src_pad = NULL, *sink_pad = NULL;
   GstElement *alphademux = NULL;
-  GstElement *multiqueue = NULL;
+  GstElement *queue = NULL;
+  GstElement *alpha_queue = NULL;
   GstElement *decoder = NULL;
   GstElement *alpha_decoder = NULL;
   GstElement *alphacombine = NULL;
@@ -118,19 +119,20 @@ gst_alpha_decode_bin_constructed (GObject * obj)
     goto cleanup;
   }
 
-  multiqueue = gst_element_factory_make ("multiqueue", NULL);
-  if (!multiqueue) {
-    priv->missing_element = "multiqueue";
+  queue = gst_element_factory_make ("queue", NULL);
+  alpha_queue = gst_element_factory_make ("queue", NULL);
+  if (!queue || !alpha_queue) {
+    priv->missing_element = "queue";
     goto cleanup;
   }
 
-  decoder = gst_element_factory_make (klass->decoder_name, NULL);
+  decoder = gst_element_factory_make (klass->decoder_name, "maindec");
   if (!decoder) {
     priv->missing_element = klass->decoder_name;
     goto cleanup;
   }
 
-  alpha_decoder = gst_element_factory_make (klass->decoder_name, NULL);
+  alpha_decoder = gst_element_factory_make (klass->decoder_name, "alphadec");
   if (!alpha_decoder) {
     priv->missing_element = klass->decoder_name;
     goto cleanup;
@@ -142,7 +144,7 @@ gst_alpha_decode_bin_constructed (GObject * obj)
     goto cleanup;
   }
 
-  gst_bin_add_many (GST_BIN (self), alphademux, multiqueue, decoder,
+  gst_bin_add_many (GST_BIN (self), alphademux, queue, alpha_queue, decoder,
       alpha_decoder, alphacombine, NULL);
 
   /* link elements */
@@ -150,34 +152,21 @@ gst_alpha_decode_bin_constructed (GObject * obj)
   gst_ghost_pad_set_target (GST_GHOST_PAD (sink_gpad), sink_pad);
   gst_clear_object (&sink_pad);
 
-  sink_pad = gst_element_request_pad_simple (multiqueue, "sink_0");
-  src_pad = gst_element_get_static_pad (multiqueue, "src_0");
-  g_object_set (sink_pad, "group_id", 0, NULL);
-  g_object_set (src_pad, "group_id", 0, NULL);
-  gst_clear_object (&sink_pad);
-  gst_clear_object (&src_pad);
-  gst_element_link_pads (alphademux, "src", multiqueue, "sink_0");
-  gst_element_link_pads (multiqueue, "src_0", decoder, "sink");
+  gst_element_link_pads (alphademux, "src", queue, "sink");
+  gst_element_link_pads (queue, "src", decoder, "sink");
   gst_element_link_pads (decoder, "src", alphacombine, "sink");
 
-  sink_pad = gst_element_request_pad_simple (multiqueue, "sink_1");
-  src_pad = gst_element_get_static_pad (multiqueue, "src_1");
-  g_object_set (sink_pad, "group_id", 1, NULL);
-  g_object_set (src_pad, "group_id", 1, NULL);
-  gst_clear_object (&sink_pad);
-  gst_clear_object (&src_pad);
-  gst_element_link_pads (alphademux, "alpha", multiqueue, "sink_1");
-  gst_element_link_pads (multiqueue, "src_1", alpha_decoder, "sink");
+  gst_element_link_pads (alphademux, "alpha", alpha_queue, "sink");
+  gst_element_link_pads (alpha_queue, "src", alpha_decoder, "sink");
   gst_element_link_pads (alpha_decoder, "src", alphacombine, "alpha");
 
   src_pad = gst_element_get_static_pad (alphacombine, "src");
   gst_ghost_pad_set_target (GST_GHOST_PAD (src_gpad), src_pad);
   gst_object_unref (src_pad);
 
-  gst_element_link_pads (alphademux, "alpha", multiqueue, "sink_0");
-
-  /* configure the elements */
-  g_object_set (multiqueue, "max-size-bytes", 0, "max-size-time", 0,
+  g_object_set (queue, "max-size-bytes", 0, "max-size-time", 0,
+      "max-size-buffers", 1, NULL);
+  g_object_set (alpha_queue, "max-size-bytes", 0, "max-size-time", 0,
       "max-size-buffers", 1, NULL);
 
   /* signal success, we will handle this in NULL->READY transition */
@@ -186,7 +175,8 @@ gst_alpha_decode_bin_constructed (GObject * obj)
 
 cleanup:
   gst_clear_object (&alphademux);
-  gst_clear_object (&multiqueue);
+  gst_clear_object (&queue);
+  gst_clear_object (&alpha_queue);
   gst_clear_object (&decoder);
   gst_clear_object (&alpha_decoder);
   gst_clear_object (&alphacombine);