If there is no frame from the master card after 100 ms, tick anyway.

[nageru] / nageru / mixer.cpp

diff --git a/nageru/mixer.cpp b/nageru/mixer.cpp
index 85e5ade8dc294061b0b4af58e606abc4fcd2db5f..827ab9fd9dfa4b41ca31649d7dcd6cb0d09c9434 100644 (file)
--- a/nageru/mixer.cpp
+++ b/nageru/mixer.cpp
@@ -1316,7 +1316,9 @@ void Mixer::thread_func()
 
                // If the first card is reporting a corrupted or otherwise dropped frame,
                // just increase the pts (skipping over this frame) and don't try to compute anything new.
-               if (!master_card_is_output && new_frames[master_card_index].frame->len == 0) {
+               if (!master_card_is_output &&
+                   new_frames[master_card_index].frame != nullptr &&  // Timeout.
+                   new_frames[master_card_index].frame->len == 0) {
                        ++stats_dropped_frames;
                        pts_int += new_frames[master_card_index].length;
                        continue;
@@ -1470,21 +1472,33 @@ 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);
 start:
        unique_lock<mutex> lock(card_mutex, defer_lock);
+       bool timed_out = false;
        if (master_card_is_output) {
                // Clocked to the output, so wait for it to be ready for the next frame.
                cards[master_card_index].output->wait_for_frame(pts_int, &output_frame_info.dropped_frames, &output_frame_info.frame_duration, &output_frame_info.is_preroll, &output_frame_info.frame_timestamp);
                lock.lock();
        } else {
                // Wait for the master card to have a new frame.
-               // TODO: Add a timeout.
                output_frame_info.is_preroll = false;
                lock.lock();
-               cards[master_card_index].new_frames_changed.wait(lock, [this, master_card_index]{ return !cards[master_card_index].new_frames.empty() || cards[master_card_index].capture->get_disconnected(); });
-       }
-
-       if (master_card_is_output) {
+               timed_out = !cards[master_card_index].new_frames_changed.wait_for(lock,
+                       master_card_timeout,
+                       [this, master_card_index]{
+                               return !cards[master_card_index].new_frames.empty() ||
+                                       cards[master_card_index].capture->get_disconnected();
+                       });
+       }
+
+       if (timed_out) {
+               // The master card stalled for 100 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.
+               handle_hotplugged_cards();
+       } else if (master_card_is_output) {
                handle_hotplugged_cards();
        } else if (cards[master_card_index].new_frames.empty()) {
                // We were woken up, but not due to a new frame. Deal with it
@@ -1519,7 +1533,13 @@ start:
                raw_audio[card_index] = move(card->new_raw_audio);
        }
 
-       if (!master_card_is_output) {
+       if (timed_out) {
+               // Pretend the frame happened a while ago and was only processed now,
+               // so that we get the duration sort-of right. This isn't ideal.
+               output_frame_info.dropped_frames = 0;  // Hard to define, really.
+               output_frame_info.frame_duration = lrint(TIMEBASE * duration<double>(master_card_timeout).count());
+               output_frame_info.frame_timestamp = steady_clock::now() - master_card_timeout;
+       } else if (!master_card_is_output) {
                output_frame_info.frame_timestamp = new_frames[master_card_index].received_timestamp;
                output_frame_info.dropped_frames = new_frames[master_card_index].dropped_frames;
                output_frame_info.frame_duration = new_frames[master_card_index].length;