When hot-unplugging capture cards, actually allow making them inactive.

[nageru] / nageru / mixer.cpp

diff --git a/nageru/mixer.cpp b/nageru/mixer.cpp
index cbca327e07663326a0eee26512939d093f1f59e3..5df80dfba0c2923820e014df5572284d9f6ed8b3 100644 (file)
--- a/nageru/mixer.cpp
+++ b/nageru/mixer.cpp
@@ -1276,6 +1276,11 @@ void Mixer::thread_func()
                        output->start_output(desired_output_video_mode, pts_int);
                }
 
+               {
+                       lock_guard<mutex> lock(card_mutex);
+                       handle_hotplugged_cards();
+               }
+
                CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
                bool has_new_frame[MAX_VIDEO_CARDS] = { false };
 
@@ -1290,11 +1295,6 @@ void Mixer::thread_func()
                        assert(master_card_index < MAX_VIDEO_CARDS);
                }
 
-               {
-                       lock_guard<mutex> lock(card_mutex);
-                       handle_hotplugged_cards();
-               }
-
                vector<int32_t> raw_audio[MAX_VIDEO_CARDS];  // For MJPEG encoding.
                OutputFrameInfo output_frame_info = get_one_frame_from_each_card(master_card_index, master_card_is_output, new_frames, has_new_frame, raw_audio);
                schedule_audio_resampling_tasks(output_frame_info.dropped_frames, output_frame_info.num_samples, output_frame_info.frame_duration, output_frame_info.is_preroll, output_frame_info.frame_timestamp);
@@ -1485,8 +1485,9 @@ start:
                lock.lock();
                timed_out = !cards[master_card_index].new_frames_changed.wait_for(lock,
                        master_card_timeout,
-                       [this, master_card_index]{
+                       [this, master_card_index] {
                                return !cards[master_card_index].new_frames.empty() ||
+                                       cards[master_card_index].capture == nullptr ||
                                        cards[master_card_index].capture->get_disconnected();
                        });
                if (timed_out) {
@@ -1507,7 +1508,8 @@ start:
        } else if (cards[master_card_index].new_frames.empty()) {
                // We were woken up, but not due to a new frame. Deal with it
                // and then restart.
-               assert(cards[master_card_index].capture->get_disconnected());
+               assert(cards[master_card_index].capture == nullptr ||
+                      cards[master_card_index].capture->get_disconnected());
                handle_hotplugged_cards();
                lock.unlock();
                goto start;
@@ -1594,11 +1596,23 @@ void Mixer::handle_hotplugged_cards()
        for (unsigned card_index = 0; card_index < MAX_VIDEO_CARDS; ++card_index) {
                CaptureCard *card = &cards[card_index];
                if (card->capture != nullptr && card->capture->get_disconnected()) {
-                       fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
-                       FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
-                       configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr, /*is_srt_card=*/false);
-                       card->queue_length_policy.reset(card_index);
-                       card->capture->start_bm_capture();
+                       bool is_active = card_index < unsigned(global_flags.min_num_cards) || cards[card_index].force_active;
+                       if (is_active) {
+                               fprintf(stderr, "Card %u went away, replacing with a fake card.\n", card_index);
+                               FakeCapture *capture = new FakeCapture(global_flags.width, global_flags.height, FAKE_FPS, OUTPUT_FREQUENCY, card_index, global_flags.fake_cards_audio);
+                               configure_card(card_index, capture, CardType::FAKE_CAPTURE, /*output=*/nullptr, /*is_srt_card=*/false);
+                               card->queue_length_policy.reset(card_index);
+                               card->capture->start_bm_capture();
+                       } else {
+                               // NOTE: The theme might end up forcing the card back at some later point
+                               // (ie., force_active is false now, but might immediately be true again on
+                               // e.g. the next frame). That should be rare, though, so we don't bother
+                               // adjusting the message.
+                               fprintf(stderr, "Card %u went away, removing. (To keep a fake card, increase --num-cards.)\n", card_index);
+                               theme->remove_card(card_index);
+                               configure_card(card_index, /*capture=*/nullptr, CardType::FAKE_CAPTURE, /*output=*/nullptr, /*is_srt_card=*/false);
+                               card->queue_length_policy.reset(card_index);
+                       }
                }
        }