From 9d973d0f3527dfa05cc324bdf353db046e400e75 Mon Sep 17 00:00:00 2001
From: Andrew Voznytsa <andrew.voznytsa@gmail.com>
Date: Tue, 31 Mar 2020 21:26:22 +0300
Subject: [PATCH] Force parsebin to output frame aligned stream

---
 src/VideoReceiver/GstVideoReceiver.cc | 54 +++++++++++++++++++++++++++
 src/VideoReceiver/GstVideoReceiver.h  |  1 +
 2 files changed, 55 insertions(+)

diff --git a/src/VideoReceiver/GstVideoReceiver.cc b/src/VideoReceiver/GstVideoReceiver.cc
index 6e6ea4085..857c6fef4 100644
--- a/src/VideoReceiver/GstVideoReceiver.cc
+++ b/src/VideoReceiver/GstVideoReceiver.cc
@@ -729,6 +729,8 @@ GstVideoReceiver::_makeSource(const QString& uri)
             break;
         }
 
+        g_signal_connect(parser, "autoplug-query", G_CALLBACK(_filterParserCaps), nullptr);
+
         gst_bin_add_many(GST_BIN(bin), source, parser, nullptr);
 
         // FIXME: AV: Android does not determine MPEG2-TS via parsebin - have to explicitly state which demux to use
@@ -1434,6 +1436,58 @@ GstVideoReceiver::_padProbe(GstElement* element, GstPad* pad, gpointer user_data
     return TRUE;
 }
 
+gboolean
+GstVideoReceiver::_filterParserCaps(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data)
+{
+    Q_UNUSED(bin)
+    Q_UNUSED(pad)
+    Q_UNUSED(element)
+    Q_UNUSED(data)
+
+    if (GST_QUERY_TYPE(query) != GST_QUERY_CAPS) {
+        return FALSE;
+    }
+
+    GstCaps* srcCaps;
+
+    gst_query_parse_caps(query, &srcCaps);
+
+    if (srcCaps == nullptr || gst_caps_is_any(srcCaps)) {
+        return FALSE;
+    }
+
+    GstCaps* sinkCaps = nullptr;
+
+    GstCaps* filter;
+
+    if (sinkCaps == nullptr && (filter = gst_caps_from_string("video/x-h264")) != nullptr) {
+        if (gst_caps_can_intersect(srcCaps, filter)) {
+            sinkCaps = gst_caps_from_string("video/x-h264,stream-format=avc");
+        }
+
+        gst_caps_unref(filter);
+        filter = nullptr;
+    } else if (sinkCaps == nullptr && (filter = gst_caps_from_string("video/x-h265")) != nullptr) {
+        if (gst_caps_can_intersect(srcCaps, filter)) {
+            sinkCaps = gst_caps_from_string("video/x-h265,stream-format=hvc1");
+        }
+
+        gst_caps_unref(filter);
+        filter = nullptr;
+    }
+
+    if (sinkCaps == nullptr) {
+        return FALSE;
+    }
+
+    gst_query_set_caps_result(query, sinkCaps);
+
+    gst_caps_unref(sinkCaps);
+    sinkCaps = nullptr;
+
+    return TRUE;
+}
+
 gboolean
 GstVideoReceiver::_autoplugQueryCaps(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data)
 {
diff --git a/src/VideoReceiver/GstVideoReceiver.h b/src/VideoReceiver/GstVideoReceiver.h
index a16d96eaf..c59dbdab0 100644
--- a/src/VideoReceiver/GstVideoReceiver.h
+++ b/src/VideoReceiver/GstVideoReceiver.h
@@ -131,6 +131,7 @@ private:
     static void _wrapWithGhostPad(GstElement* element, GstPad* pad, gpointer data);
     static void _linkPadWithOptionalBuffer(GstElement* element, GstPad* pad, gpointer data);
     static gboolean _padProbe(GstElement* element, GstPad* pad, gpointer user_data);
+    static gboolean _filterParserCaps(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data);
     static gboolean _autoplugQueryCaps(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data);
     static gboolean _autoplugQueryContext(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data);
     static gboolean _autoplugQuery(GstElement* bin, GstPad* pad, GstElement* element, GstQuery* query, gpointer data);
-- 
2.22.0