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 26296180ac1371a0f14486849d451639d7a3d092..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);
@@ -1471,7 +1471,7 @@ pair<string, string> Mixer::get_channel_color_http(unsigned channel_idx)
 Mixer::OutputFrameInfo Mixer::get_one_frame_from_each_card(unsigned master_card_index, bool master_card_is_output, CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS], bool has_new_frame[MAX_VIDEO_CARDS], vector<int32_t> raw_audio[MAX_VIDEO_CARDS])
 {
        OutputFrameInfo output_frame_info;
-       constexpr steady_clock::duration master_card_timeout = milliseconds(100);
+       constexpr steady_clock::duration master_card_timeout = milliseconds(200);
 start:
        unique_lock<mutex> lock(card_mutex, defer_lock);
        bool timed_out = false;
@@ -1485,18 +1485,20 @@ 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) {
-                       fprintf(stderr, "WARNING: Master card (%s) did not deliver a frame for 100 ms, creating a fake one.\n",
-                               description_for_card(master_card_index).c_str());
+                       fprintf(stderr, "WARNING: Master card (%s) did not deliver a frame for %u ms, creating a fake one.\n",
+                               description_for_card(master_card_index).c_str(),
+                               unsigned(duration_cast<milliseconds>(master_card_timeout).count()));
                }
        }
 
        if (timed_out) {
-               // The master card stalled for 100 ms (possible when it's e.g.
+               // The master card stalled for 200 ms (possible when it's e.g.
                // an SRT card). Send a frame no matter what; this also makes sure
                // any other cards get to empty their queues, and in general,
                // that we make _some_ sort of forward progress.
@@ -1506,7 +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;
@@ -1576,6 +1579,14 @@ start:
        fractional_samples = num_samples_times_timebase % TIMEBASE;
        assert(output_frame_info.num_samples >= 0);
 
+       if (timed_out) {
+               DeviceSpec device{InputSourceType::CAPTURE_CARD, master_card_index};
+               bool success;
+               do {
+                       success = audio_mixer->add_silence(device, output_frame_info.num_samples, /*dropped_frames=*/0);
+               } while (!success);
+       }
+
        return output_frame_info;
 }
 
@@ -1585,11 +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);
+                       }
                }
        }