From 1ac30ad53fff9b572212d7727695b1424b803214 Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Tue, 25 May 2021 19:47:28 +0900
Subject: [PATCH] interlace: Drop framerate from query caps of sinkpad

Query caps should return caps which represent the element can accept,
not resulting format.

Fixing negotiation error with
gst-launch-1.0 videotestsrc ! video/x-raw,framerate=25/1 ! interlace field-pattern=0 ! fakesink

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2282>
---
 gst/interlace/gstinterlace.c | 21 ++++++++++++++-------
 1 file changed, 14 insertions(+), 7 deletions(-)

diff --git a/gst/interlace/gstinterlace.c b/gst/interlace/gstinterlace.c
index 409de1b1eb..8858d97f23 100644
--- a/gst/interlace/gstinterlace.c
+++ b/gst/interlace/gstinterlace.c
@@ -980,18 +980,25 @@ gst_interlace_getcaps (GstPad * pad, GstInterlace * interlace, GstCaps * filter)
     icaps = gst_caps_merge (icaps, alternate);
   }
 
-  if (pattern == GST_INTERLACE_PATTERN_1_1) {
-    icaps =
-        gst_interlace_caps_double_framerate (icaps, (pad == interlace->srcpad),
-        FALSE);
-  } else if (pattern != GST_INTERLACE_PATTERN_2_2) {
-    GST_FIXME_OBJECT (interlace,
-        "Add calculations for telecine framerate conversions");
+  /* Drop framerate for sinkpad */
+  if (pad == interlace->sinkpad) {
     for (i = 0; i < gst_caps_get_size (icaps); ++i) {
       GstStructure *s = gst_caps_get_structure (icaps, i);
 
       gst_structure_remove_field (s, "framerate");
     }
+  } else {
+    if (pattern == GST_INTERLACE_PATTERN_1_1) {
+      icaps = gst_interlace_caps_double_framerate (icaps, TRUE, FALSE);
+    } else if (pattern != GST_INTERLACE_PATTERN_2_2) {
+      GST_FIXME_OBJECT (interlace,
+          "Add calculations for telecine framerate conversions");
+      for (i = 0; i < gst_caps_get_size (icaps); ++i) {
+        GstStructure *s = gst_caps_get_structure (icaps, i);
+
+        gst_structure_remove_field (s, "framerate");
+      }
+    }
   }
 
   if (clean_filter)