Fixes and improvements for Kdenlive adapter (#1390)

* Add global marker import/export
* Add unsupported clip placeholder only if needed
* [Kdenlive adapter] Refactor, fix and extend
- Add support for SMPTE bars (read and write)
- Fix reading of projects with "mixes" (only reading yet)
- Add support for clip markers (only reading yet)
- Move some code parts to functions to improve readability, reusablity
and testability.
* [Kdenlive adapter] extend tests
* [Kdenlive adapter] Fix linting
* Update plugin documentation after Kdenlive adapter update

Signed-off-by: Julius Künzel <[email protected]>

Author: jlskuz

contrib/opentimelineio_contrib/adapters/kdenlive.py

@@ -0,0 +1,70 @@
+{
+    "OTIO_SCHEMA": "Timeline.1", 
+    "metadata": {}, 
+    "name": "transition_test", 
+    "tracks": {
+        "OTIO_SCHEMA": "Stack.1", 
+        "children": [
+            {
+                "OTIO_SCHEMA": "Sequence.1", 
+                "children": [
+                    {
+                        "OTIO_SCHEMA": "Clip.1", 
+                        "effects": [],
+                        "markers": [], 
+                        "enabled": true,
+                        "media_reference": {
+                            "OTIO_SCHEMA" : "GeneratorReference.1",
+                            "available_range" : {
+                                "OTIO_SCHEMA": "TimeRange.1", 
+                                "duration": {
+                                    "OTIO_SCHEMA": "RationalTime.1", 
+                                    "rate": 24, 
+                                    "value": 50
+                                }, 
+                                "start_time": {
+                                    "OTIO_SCHEMA": "RationalTime.1", 
+                                    "rate": 24, 
+                                    "value": 0.0
+                                }
+                            },
+                            "generator_kind" : "SMPTEBars",
+                            "metadata" : {},
+                            "parameters" : {},
+                            "name" : "bars"
+                        }, 
+                        "metadata": {}, 
+                        "name": "C", 
+                        "source_range": {
+                            "OTIO_SCHEMA": "TimeRange.1", 
+                            "duration": {
+                                "OTIO_SCHEMA": "RationalTime.1", 
+                                "rate": 24, 
+                                "value": 50
+                            }, 
+                            "start_time": {
+                                "OTIO_SCHEMA": "RationalTime.1", 
+                                "rate": 24, 
+                                "value": 0.0
+                            }
+                        }
+
+                    }
+                ], 
+                "effects": [], 
+                "kind": "Video",
+                "markers": [], 
+                "enabled": true,
+                "metadata": {}, 
+                "name": "Sequence1", 
+                "source_range": null
+            }
+        ], 
+        "effects": [],
+        "markers": [], 
+        "enabled": true,
+        "metadata": {}, 
+        "name": "tracks", 
+        "source_range": null
+    }
+}

contrib/opentimelineio_contrib/adapters/tests/sample_data/generator_reference_test.otio

@@ -264,6 +264,7 @@
   <property name="kdenlive:folderid">-1</property>
   <property name="kdenlive:id">10</property>
   <property name="kdenlive:file_hash">de362639624a26f69e4278e90d059408</property>
+  <property name="kdenlive:clipname">Placeholder: Unsupported clip type</property>
   <property name="force_reload">0</property>
   <property name="meta.media.width">768</property>
   <property name="meta.media.height">576</property>