Add stream camera controls and preserve playback on changes

tools/chatgui/src/streamplayer_window.cpp

@@ -179,6 +179,7 @@ void StreamPlayerWindow::decode() {
     bool waitKey = true, opened = false;
     int64_t deadline = nowUs() + 10000000, reportAt = nowUs(), expectedAudio = -1;
     uint64_t decoded = 0, discarded = 0;
+    uint32_t videoRevision = 0;
     auto reset = [&] {
         avcodec_free_context(&decoder);
         opus_codec_decoder_destroy(opus); opus = nullptr; expectedAudio = -1; waitKey = true;
@@ -239,6 +240,13 @@ void StreamPlayerWindow::decode() {
             } else expectedAudio = static_cast<int64_t>(record.pts) + 20000;
             continue;
         }
+        if (videoRevision != record.format.revision) {
+            DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop video revision=%u->%u dimensions=%ux%u rotation=%u; preserve audio",
+                       videoRevision, record.format.revision, record.format.width, record.format.height, record.format.rotation);
+            avcodec_free_context(&decoder); av_frame_unref(frame); waitKey = true; videoRevision = record.format.revision;
+            { std::lock_guard<std::mutex> guard(p.lock); p.videos.clear(); }
+            deadline = nowUs() + 10000000;
+        }
         if (waitKey && !(record.flags & STREAM_MEDIA_KEY)) continue;
         if (!decoder) {
             const AVCodec* codec = avcodec_find_decoder(AV_CODEC_ID_H264);