From dc2c61faf5ef285fd82faa8bfbb553a5c895421d Mon Sep 17 00:00:00 2001
From: =?utf8?q?Sebastian=20Dr=C3=B6ge?= <sebastian.droege@collabora.co.uk>
Date: Thu, 24 Nov 2011 10:14:06 +0100
Subject: [PATCH] mpegvideoparse: Implement ::get_sink_caps vfunc to propagate
 downstream caps constraints upstream

---
 gst/videoparsers/gstmpegvideoparse.c | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/gst/videoparsers/gstmpegvideoparse.c b/gst/videoparsers/gstmpegvideoparse.c
index 66a8929..ca392a7 100644
--- a/gst/videoparsers/gstmpegvideoparse.c
+++ b/gst/videoparsers/gstmpegvideoparse.c
@@ -71,6 +71,7 @@ static gboolean gst_mpegv_parse_check_valid_frame (GstBaseParse * parse,
 static GstFlowReturn gst_mpegv_parse_parse_frame (GstBaseParse * parse,
     GstBaseParseFrame * frame);
 static gboolean gst_mpegv_parse_set_caps (GstBaseParse * parse, GstCaps * caps);
+static GstCaps *gst_mpegv_parse_get_caps (GstBaseParse * parse);
 static GstFlowReturn gst_mpegv_parse_pre_push_frame (GstBaseParse * parse,
     GstBaseParseFrame * frame);
 
@@ -166,6 +167,7 @@ gst_mpegv_parse_class_init (GstMpegvParseClass * klass)
       GST_DEBUG_FUNCPTR (gst_mpegv_parse_check_valid_frame);
   parse_class->parse_frame = GST_DEBUG_FUNCPTR (gst_mpegv_parse_parse_frame);
   parse_class->set_sink_caps = GST_DEBUG_FUNCPTR (gst_mpegv_parse_set_caps);
+  parse_class->get_sink_caps = GST_DEBUG_FUNCPTR (gst_mpegv_parse_get_caps);
   parse_class->pre_push_frame =
       GST_DEBUG_FUNCPTR (gst_mpegv_parse_pre_push_frame);
 }
@@ -762,3 +764,35 @@ gst_mpegv_parse_set_caps (GstBaseParse * parse, GstCaps * caps)
   /* let's not interfere and accept regardless of config parsing success */
   return TRUE;
 }
+
+static GstCaps *
+gst_mpegv_parse_get_caps (GstBaseParse * parse)
+{
+  GstCaps *peercaps;
+  GstCaps *res;
+
+  peercaps = gst_pad_get_allowed_caps (GST_BASE_PARSE_SRC_PAD (parse));
+  if (peercaps) {
+    guint i, n;
+
+    /* Remove the parsed field */
+    peercaps = gst_caps_make_writable (peercaps);
+    n = gst_caps_get_size (peercaps);
+    for (i = 0; i < n; i++) {
+      GstStructure *s = gst_caps_get_structure (peercaps, i);
+      gst_structure_remove_field (s, "parsed");
+    }
+
+    res =
+        gst_caps_intersect_full (peercaps,
+        gst_pad_get_pad_template_caps (GST_BASE_PARSE_SINK_PAD (parse)),
+        GST_CAPS_INTERSECT_FIRST);
+    gst_caps_unref (peercaps);
+  } else {
+    res =
+        gst_caps_copy (gst_pad_get_pad_template_caps (GST_BASE_PARSE_SINK_PAD
+            (parse)));
+  }
+
+  return res;
+}
-- 
2.7.4