Fallback desktop video on decoder rejection and verify receive-only codecs

tools/chatgui/tests/test_call_video_encoder.cpp

@@ -45,6 +45,11 @@ private slots:
     void switchesAtScheduledIdr_data() {
         QTest::addColumn<int>("codec"); QTest::newRow("H264") << 1; QTest::newRow("H265") << 2;
     }
+    void independentDecoders() {
+        auto caps = CallVideoDecoder::capabilities();
+        QCOMPARE(caps.decode[0].profiles, uint8_t(3)); QCOMPARE(caps.decode[1].profiles, uint8_t(1));
+        QCOMPARE(caps.encode[0].width, uint16_t(0)); QCOMPARE(caps.encode[1].width, uint16_t(0));
+    }
     void switchesAtScheduledIdr() {
         QFETCH(int, codec);
         auto config = configuration(codec);