Keep live decoding low latency and preserve publisher stop controls

tools/chatgui/src/streamplayer_window.cpp

@@ -243,6 +243,7 @@ void StreamPlayerWindow::decode() {
         if (!decoder) {
             const AVCodec* codec = avcodec_find_decoder(AV_CODEC_ID_H264);
             decoder = codec ? avcodec_alloc_context3(codec) : nullptr;
+            if (decoder) { decoder->thread_count = 1; decoder->flags |= AV_CODEC_FLAG_LOW_DELAY; }
             if (!decoder || avcodec_open2(decoder, codec, nullptr) < 0) { fail(text("Stream video decoder failed")); break; }
             decoder->pkt_timebase = AVRational{1, 1000000};
             waitKey = false;