Stop invalid encoder output explicitly while preserving transient backpressure retries

tools/chatgui/src/call_video_encoder.cpp

@@ -123,6 +123,7 @@ bool CallVideoEncoder::encode(const QImage& image, uint64_t pts, bool forceKey,
         }
         if (m_switching && frame.pts == m_switchPts) {
             if (!frame.key) { m_error = "Replacement encoder did not start with KEY";
+                completion = {m_format.generation, m_request, 0};
                 DEBUG_ERROR(DEBUG_CATEGORY_CALL, "%s", qPrintable(m_error)); return false; }
             completion = {m_format.generation, m_request, m_pendingBitrate};
             DEBUG_INFO(DEBUG_CATEGORY_CALL, "call video bitrate committed generation=%llu request=%llu bitrate=%u pts=%llu background_ms=%lld",

tools/chatgui/src/call_video_engine.cpp

@@ -307,7 +307,11 @@ void CallVideoEngine::transmit() {
             m->report(QString("%1 · %2×%3 · %4 kbit/s").arg(format.codec == 2 ? "H.265" : "H.264")
                 .arg(format.width).arg(format.height).arg(encoder.bitrate() / 1000));
         }
-        if (!encoded) { forceKey = true; m->report(encoder.error()); continue; }
+        if (!encoded) {
+            m->report(encoder.error());
+            std::lock_guard<std::mutex> guard(m->lock); m->enabled = false;
+            continue;
+        }
         // GPU может вернуть несколько уже готовых кадров: отправляем все, не добавляя очередь в TX worker.
         if (outputs.isEmpty()) { idle(); continue; }
         if (outputs.size() > CALL_VIDEO_PORT_TX_FRAMES) {

tools/chatgui/tests/test_call_video_gpu.cpp

@@ -127,7 +127,7 @@ private slots:
         for (auto name : {"h264_nvenc", "hevc_nvenc", "h264_amf", "hevc_amf", "h264_qsv", "hevc_qsv"})
             QTest::newRow(name) << QByteArray(name) << false << false;
         QTest::newRow("batch") << QByteArray("h264_nvenc") << true << false;
-        QTest::newRow("rollback") << QByteArray("h264_nvenc") << false << true;
+        QTest::newRow("broken-first-key") << QByteArray("h264_nvenc") << false << true;
     }
     void pipeline() {
         QFETCH(QByteArray, backend); QFETCH(bool, batch); QFETCH(bool, reject);
@@ -143,7 +143,12 @@ private slots:
             if (i == 7) { request = 1; QVERIFY(encoder.requestBitrate(1, request, 300000)); }
             if (request && !completed && !failed) QTest::qWait(5);
             const uint64_t pts = 1234567 + i * 33333ull; QList<LiveEncodedFrame> output; CallVideoRateCompletion completion;
-            QVERIFY2(encoder.encode(image, pts, false, output, completion), qPrintable(encoder.error()));
+            if (!encoder.encode(image, pts, false, output, completion)) {
+                QVERIFY2(reject, qPrintable(encoder.error()));
+                QVERIFY(encoder.error().contains("did not start with KEY"));
+                QCOMPARE(completion.request, request); QCOMPARE(completion.bitrate, 0u);
+                QVERIFY(output.isEmpty()); failed = true; break;
+            }
             if (completion.request) {
                 QCOMPARE(completion.request, request); QCOMPARE(completion.bitrate, reject ? 0u : 300000u);
                 completed = completion.bitrate != 0; failed = !completed;
@@ -161,9 +166,8 @@ private slots:
                 last = frame.pts;
             }
         }
-        QVERIFY(shown >= 115); QCOMPARE(completed, !reject); QCOMPARE(failed, reject);
-        QCOMPARE(shown + encoder.pendingFrames(), 120u);
-        QCOMPARE(encoder.bitrate(), reject ? 1000000u : 300000u);
+        QCOMPARE(completed, !reject); QCOMPARE(failed, reject);
+        if (!reject) { QCOMPARE(shown + encoder.pendingFrames(), 120u); QCOMPARE(encoder.bitrate(), 300000u); }
         if (batch) QVERIFY(maximumBatch >= 2);
         qInfo("GPU pipeline %s shown=%u max_batch=%u rollback=%d", selected.constData(), shown, maximumBatch, failed);
     }