Prepare one desktop media response per player request

tools/chatgui/transport/stream_bridge.cpp

@@ -21,7 +21,8 @@ struct Bridge {
     uint64_t watch = 0;
     bool watchPending = false, opening = false, stopping = false;
     bool wantRead = false, waiting = false, resync = false;
-    int64_t position = -1, videoAhead = STREAM_MEDIA_READ_AHEAD_US, audioAhead = STREAM_MEDIA_READ_AHEAD_US;
+    bool wantVideo = false;
+    int64_t position = -1, audioAhead = STREAM_MEDIA_READ_AHEAD_US;
     stream_media_status status{};
     uint64_t statusId = 0;
     Viewer viewer, requested;
@@ -93,7 +94,7 @@ void mediaEvent(UTUN_INSTANCE* inst, const stream_event* event, void*) {
         || event->descriptor.source_node_id != bridge.viewer.source || event->descriptor.source_epoch != bridge.viewer.epoch) return;
     if (event->type == STREAM_EVENT_CLOSED || !stream_handle_active(bridge.handle))
         closeViewer(StreamRecordKind::Closed, event->reason);
-    else if (event->type == STREAM_EVENT_AVAILABLE) { bridge.wantRead = true; bridge.waiting = false; schedule(); }
+    else if (event->type == STREAM_EVENT_AVAILABLE) { bridge.waiting = false; schedule(); }
 }
 
 /* Сериализованный actor: старый owner закрывается перед открытием нового выбранного источника. */
@@ -140,7 +141,7 @@ void process(void*) {
         DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop viewer opened id=%llu group=%llx source=%llx epoch=%llx",
                    (unsigned long long)bridge.viewer.id, (unsigned long long)bridge.viewer.group,
                    (unsigned long long)bridge.viewer.source, (unsigned long long)bridge.viewer.epoch);
-        bridge.wantRead = true;
+        bridge.wantRead = false;
     }
     if (!bridge.handle) return;
     if (bridge.resync) {
@@ -152,23 +153,21 @@ void process(void*) {
         DEBUG_ERROR(DEBUG_CATEGORY_STREAM, "desktop media index failed result=%d", statusResult);
         closeViewer(StreamRecordKind::Closed, STREAM_CLOSE_FAILED); return;
     }
-    unsigned prepared = 0;
-    for (const auto& record : bridge.output)
-        if (record.id == bridge.viewer.id && (record.kind == StreamRecordKind::Video || record.kind == StreamRecordKind::Audio)) prepared++;
-    if (!bridge.wantRead || prepared >= 2 || bridge.bytes + STREAM_MEDIA_MAX_FRAME > 4u * 1024u * 1024u) return;
+    bool prepared = std::any_of(bridge.output.begin(), bridge.output.end(), [](const StreamRecord& r) { return r.id == bridge.viewer.id; });
+    if (!bridge.wantRead || prepared || bridge.bytes + STREAM_MEDIA_MAX_FRAME > 4u * 1024u * 1024u) return;
     bridge.wantRead = false;
     stream_media_packet packet{};
-    int result = stream_media_read(bridge.handle, bridge.position, bridge.videoAhead, bridge.audioAhead, &packet);
-    DEBUG_TRACE(DEBUG_CATEGORY_STREAM, "desktop media read id=%llu PTS=%lld ahead=%lld/%lld result=%d kind=%d prepared=%u records=%zu",
-        (unsigned long long)bridge.viewer.id, (long long)bridge.position, (long long)bridge.videoAhead,
-        (long long)bridge.audioAhead, result, result == STREAM_OK ? (int)packet.kind : -1, prepared, bridge.output.size());
+    int result = stream_media_read(bridge.handle, bridge.position, bridge.wantVideo, bridge.audioAhead, &packet);
+    DEBUG_TRACE(DEBUG_CATEGORY_STREAM, "desktop media read id=%llu PTS=%lld video=%d audio_ahead=%lld result=%d kind=%d records=%zu",
+        (unsigned long long)bridge.viewer.id, (long long)bridge.position, bridge.wantVideo,
+        (long long)bridge.audioAhead, result, result == STREAM_OK ? (int)packet.kind : -1, bridge.output.size());
     if (stream_media_get_status(bridge.handle, &bridge.status) < 0) result = STREAM_ERR_FORMAT;
     if (result == STREAM_OK) {
         if (packet.kind == STREAM_MEDIA_READ_END) closeViewer(StreamRecordKind::End, 0);
         else mediaFrame(nullptr, &packet.format, packet.kind == STREAM_MEDIA_READ_VIDEO ? &packet.video : nullptr,
                          packet.kind == STREAM_MEDIA_READ_AUDIO ? &packet.audio : nullptr);
     } else if (result == STREAM_MORE) { bridge.wantRead = true; schedule(); }
-    else if (result == STREAM_WAIT) bridge.waiting = true;
+    else if (result == STREAM_WAIT) bridge.wantRead = bridge.waiting = true;
     else if (result == STREAM_GAP || result == STREAM_EXPIRED) {
         DEBUG_INFO(DEBUG_CATEGORY_STREAM, "desktop playback resync id=%llu result=%d", (unsigned long long)bridge.viewer.id, result);
         stream_media_resync(bridge.handle); bridge.position = -1;
@@ -240,14 +239,16 @@ void gui_stream_stop(uint64_t id) {
     }
 }
 
-bool gui_stream_pull(uint64_t id, StreamRecord& record, int64_t position, int64_t videoAhead, int64_t audioAhead) {
+bool gui_stream_pull(uint64_t id, StreamRecord& record, int64_t position, bool wantVideo, int64_t audioAhead) {
     std::lock_guard<std::mutex> guard(bridge.lock);
     auto i = std::find_if(bridge.output.begin(), bridge.output.end(), [id](const StreamRecord& r) { return r.id == id; });
     bool found = i != bridge.output.end();
     if (found) { bridge.bytes -= static_cast<size_t>(i->data.size()); record = std::move(*i); bridge.output.erase(i); }
-    if (bridge.viewer.id == id && bridge.handle && (!bridge.waiting || bridge.position != position
-        || bridge.videoAhead != videoAhead || bridge.audioAhead != audioAhead || found)) {
-        bridge.position = position; bridge.videoAhead = videoAhead; bridge.audioAhead = audioAhead; bridge.wantRead = true; schedule();
+    if (!found && bridge.viewer.id == id && bridge.handle) {
+        bool changed = bridge.position != position || bridge.wantVideo != wantVideo || bridge.audioAhead != audioAhead;
+        bridge.position = position; bridge.wantVideo = wantVideo; bridge.audioAhead = audioAhead;
+        bridge.wantRead = wantVideo || audioAhead >= 0;
+        if (bridge.wantRead && (!bridge.waiting || changed)) { bridge.waiting = false; schedule(); }
     }
     return found;
 }

tools/chatgui/transport/stream_bridge.h

@@ -1,6 +1,6 @@
 /* Desktop live media: attach/detach в uasync до destroy ядра; остальные вызовы потокобезопасны.
  * Один общий publisher и один viewer; команды содержат IDs, не borrowed pointers ядра.
- * Подготовлено не более двух media records, общий предел RX 4MiB/16 записей.
+ * Один ответ на запрос плеера; следующий кадр не читается автоматически. Общий предел RX 4MiB/16 записей.
  * Watch до attach запоминает выбранную группу. Каталог идёт через CHAT_EVT_STREAM_SOURCES,
  * media pull читает ближайшие кадры из общего RS-кольца; копия нужна только для передачи между потоками. */
 #pragma once
@@ -27,7 +27,7 @@ bool gui_stream_watch(uint64_t group);
 bool gui_stream_open(uint64_t id, uint64_t group, uint64_t source, uint64_t epoch);
 void gui_stream_stop(uint64_t id);
 bool gui_stream_pull(uint64_t id, StreamRecord& record, int64_t position = -1,
-                      int64_t videoAhead = STREAM_MEDIA_READ_AHEAD_US, int64_t audioAhead = STREAM_MEDIA_READ_AHEAD_US);
+                      bool wantVideo = true, int64_t audioAhead = STREAM_MEDIA_READ_AHEAD_US);
 bool gui_stream_status(uint64_t id, stream_media_status& status);
 bool gui_stream_resync(uint64_t id);
 bool gui_stream_ready();