<div dir="ltr">I'd like to build a pipeline with 1 source and 3 sinks, where the sinks can be added and removed on the fly. I've seen examples using tees and valves, so my basic pipeline has 2 tees, 3 queues, 3 valves and 0-3 sinks. The pipeline mostly works, but it fails the 2nd time I create a sink for a particular valve, and only when sink.sync=true.<div> </div><div>The problem persists with a single src -> queue -> valve -> sink, as shown below. The pipeline starts fine, but when valve.drop is set to true a second time, the packets still do not flow. I've tried with live streams where sink.sync=false, and it works well. It's only when sink.sync=true that it fails.</div><div> </div><div>Any ideas? <div> </div><div>$ gst-launch-1.0 --version gst-launch-1.0 version 1.16.2 GStreamer 1.16.2 <a href="https://launchpad.net/distros/ubuntu/+source/gstreamer1.0" target="_blank">https://launchpad.net/distros/ubuntu/+source/gstreamer1.0</a> #include <thread> extern "C" { #include "gst/gst.h" #include "gst/base/gstbasesink.h" } class ValveTest { GstElement *pipeline_; GstElement *src_; GstElement *queue_; GstElement *valve_; GstElement *sink_; bool valve_drop_{false}; public: ValveTest() { if (!gst_is_initialized()) { gst_init(nullptr, nullptr); } pipeline_ = gst_pipeline_new(nullptr); src_ = gst_element_factory_make("videotestsrc", "src"); queue_ = gst_element_factory_make("queue", "queue"); valve_ = gst_element_factory_make("valve", "valve"); sink_ = gst_element_factory_make("xvimagesink", "sink"); if (!pipeline_ || !src_ || !queue_ || !valve_ || !sink_) { g_critical("create failed"); return; } gst_bin_add_many(GST_BIN(pipeline_), src_, queue_, valve_, sink_, nullptr); if (!gst_element_link_many(src_, queue_, valve_, sink_, nullptr)) { g_critical("link src ... sink failed"); return; } g_object_set(valve_, "drop", valve_drop_, nullptr); gst_base_sink_set_sync(GST_BASE_SINK(sink_), true); gst_element_set_state(pipeline_, GST_STATE_PLAYING); } void toggle_valve() { valve_drop_ = !valve_drop_; if (valve_drop_) { g_print("Drop\n"); g_object_set(valve_, "drop", true, nullptr); gst_element_set_state(sink_, GST_STATE_NULL); gst_bin_remove(GST_BIN(pipeline_), sink_); gst_object_unref(GST_OBJECT(sink_)); sink_ = nullptr; } else { g_print("The buffers must flow\n"); sink_ = gst_element_factory_make("xvimagesink", "sink"); gst_base_sink_set_sync(GST_BASE_SINK(sink_), true); gst_bin_add(GST_BIN(pipeline_), sink_); gst_element_link(valve_, sink_); gst_element_set_state(sink_, GST_STATE_PLAYING); g_object_set(valve_, "drop", false, nullptr); } } }; int main() {element ValveTest test; while (true) { using namespace std::chrono_literals; std::this_thread::sleep_for(2s); test.toggle_valve(); } return 0; } Thanks for any help! /Clyde<div class="gmail-yj6qo"></div><div class="gmail-adL"> </div></div></div></div>