Verify live desktop codec changes preserve the audio epoch

tools/chatgui/src/stream_publish_engine.cpp

@@ -428,17 +428,19 @@ void StreamPublishEngine::videoLoop() {
                     if (generation == m->generation) { emit configurationChanged(); emit stateChanged(text("Live")); }
                 });
             } else {
-            auto candidate = std::make_unique<StreamVideoEncoder>();
-            if (!candidate->open(config.video)) {
-                QString error = candidate->error();
-                QMetaObject::invokeMethod(this, [this, generation, error] { sourceFailed(generation, error); });
-                std::unique_lock<std::mutex> lock(m->lock);
-                m->wake.wait_for(lock, std::chrono::milliseconds(100), [this, generation] { return !m->running || m->generation != generation; });
-                continue;
-            }
-            encoder = std::move(candidate); current = generation; encoding = config; revision++; lastImage = {}; lastKey = -1000000;
-            DEBUG_INFO(DEBUG_CATEGORY_VIDEO, "desktop video prepared generation=%llu revision=%u encoder=%s",
-                (unsigned long long)generation, revision, qPrintable(encoder->name()));
+                auto candidate = std::make_unique<StreamVideoEncoder>();
+                if (!candidate->open(config.video)) {
+                    QString error = candidate->error();
+                    QMetaObject::invokeMethod(this, [this, generation, error] { sourceFailed(generation, error); });
+                    std::unique_lock<std::mutex> lock(m->lock);
+                    m->wake.wait_for(lock, std::chrono::milliseconds(100), [this, generation] {
+                        return !m->running || m->generation != generation;
+                    });
+                    continue;
+                }
+                encoder = std::move(candidate); current = generation; encoding = config; revision++; lastImage = {}; lastKey = -1000000;
+                DEBUG_INFO(DEBUG_CATEGORY_VIDEO, "desktop video prepared generation=%llu revision=%u encoder=%s",
+                    (unsigned long long)generation, revision, qPrintable(encoder->name()));
             }
         }
         bool screen = config.source.kind != StreamVideoSource::Camera;

tools/chatgui/tests/test_stream_publish.cpp

@@ -253,12 +253,16 @@ private slots:
         QVERIFY(video >= 10); QVERIFY(audio >= 40); QVERIFY(latest > first + 1000000); QVERIFY(left && right > left * 3);
         opus_codec_decoder_destroy(decoder);
         auto next = config; next.video.bitrate = 1000000; next.video.rotation = 90;
+        if (engine.codecs().contains(STREAM_MEDIA_VP9)) next.video.codec = STREAM_MEDIA_VP9;
         QVERIFY(engine.reconfigure(next)); bool revised = false;
         elapsed.restart(); while (!revised && elapsed.elapsed() < 5000) {
             if (gui_stream_pull(202, out, 0, 60000000, 60000000) && out.kind == StreamRecordKind::Video && out.format.revision >= 2) revised = true;
             QTest::qWait(1);
         }
-        QVERIFY(revised); QCOMPARE(out.format.rotation, (uint16_t)90);
+        QVERIFY(revised); QCOMPARE(out.format.rotation, (uint16_t)90); QCOMPARE(out.format.video_codec, (uint8_t)next.video.codec);
+        QVERIFY(record(202, StreamRecordKind::Audio, out)); QVERIFY(out.pts > first + 1000000);
+        stream_member_state member{};
+        QCOMPARE(stream_member_load(inst, group, inst->node_id, &member, nullptr), STREAM_OK); QCOMPARE(member.source.source_epoch, epoch);
         auto invalid = next; invalid.video.fps = 61;
         QVERIFY(engine.reconfigure(invalid));
         QTRY_COMPARE_WITH_TIMEOUT(engine.config().video.fps, 15, 5000);