} // namespace
-void QueueLengthPolicy::update_policy(int queue_length)
+void QueueLengthPolicy::update_policy(unsigned queue_length)
{
- if (queue_length < 0) { // Starvation.
- if (been_at_safe_point_since_last_starvation && safe_queue_length < 5) {
+ if (queue_length == 0) { // Starvation.
+ if (been_at_safe_point_since_last_starvation && safe_queue_length < global_flags.max_input_queue_frames) {
++safe_queue_length;
- fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frames\n",
+ fprintf(stderr, "Card %u: Starvation, increasing safe limit to %u frame(s)\n",
card_index, safe_queue_length);
}
frames_with_at_least_one = 0;
been_at_safe_point_since_last_starvation = false;
return;
}
- if (queue_length > 0) {
- if (queue_length >= int(safe_queue_length)) {
+ if (queue_length >= 1) {
+ if (queue_length >= safe_queue_length) {
been_at_safe_point_since_last_starvation = true;
}
- if (++frames_with_at_least_one >= 1000 && safe_queue_length > 0) {
+ if (++frames_with_at_least_one >= 1000 && safe_queue_length > 1) {
--safe_queue_length;
- fprintf(stderr, "Card %u: Spare frames for more than 1000 frames, reducing safe limit to %u frames\n",
+ fprintf(stderr, "Card %u: Spare frames for more than 1000 frames, reducing safe limit to %u frame(s)\n",
card_index, safe_queue_length);
frames_with_at_least_one = 0;
}
if (card->surface == nullptr) {
card->surface = create_surface_with_same_format(mixer_surface);
}
- while (!card->new_frames.empty()) card->new_frames.pop();
+ while (!card->new_frames.empty()) card->new_frames.pop_front();
card->last_timecode = -1;
card->capture->configure_card();
configure_card(card_index, fake_capture, /*is_fake_capture=*/true, card->output.release());
card->queue_length_policy.reset(card_index);
card->capture->start_bm_capture();
- card->output->start_output(bmdModeHD720p5994, pts_int); // FIXME
+ desired_output_video_mode = output_video_mode = card->output->pick_video_mode(desired_output_video_mode);
+ card->output->start_output(desired_output_video_mode, pts_int);
}
output_card_index = card_index;
}
new_frame.length = frame_length;
new_frame.interlaced = false;
new_frame.dropped_frames = dropped_frames;
- card->new_frames.push(move(new_frame));
+ card->new_frames.push_back(move(new_frame));
card->new_frames_changed.notify_all();
}
return;
new_frame.upload_func = upload_func;
new_frame.dropped_frames = dropped_frames;
new_frame.received_timestamp = video_frame.received_timestamp; // Ignore the audio timestamp.
- card->new_frames.push(move(new_frame));
+ card->new_frames.push_back(move(new_frame));
card->new_frames_changed.notify_all();
}
}
if (desired_output_card_index != output_card_index) {
set_output_card_internal(desired_output_card_index);
}
+ if (output_card_index != -1 &&
+ desired_output_video_mode != output_video_mode) {
+ DeckLinkOutput *output = cards[output_card_index].output.get();
+ output->end_output();
+ desired_output_video_mode = output_video_mode = output->pick_video_mode(desired_output_video_mode);
+ output->start_output(desired_output_video_mode, pts_int);
+ }
CaptureCard::NewFrame new_frames[MAX_VIDEO_CARDS];
bool has_new_frame[MAX_VIDEO_CARDS] = { false };
return (card_index == master_card_index);
}
+void Mixer::trim_queue(CaptureCard *card, unsigned card_index)
+{
+ // Count the number of frames in the queue, including any frames
+ // we dropped. It's hard to know exactly how we should deal with
+ // dropped (corrupted) input frames; they don't help our goal of
+ // avoiding starvation, but they still add to the problem of latency.
+ // Since dropped frames is going to mean a bump in the signal anyway,
+ // we err on the side of having more stable latency instead.
+ unsigned queue_length = 0;
+ for (const CaptureCard::NewFrame &frame : card->new_frames) {
+ queue_length += frame.dropped_frames + 1;
+ }
+ card->queue_length_policy.update_policy(queue_length);
+
+ // If needed, drop frames until the queue is below the safe limit.
+ // We prefer to drop from the head, because all else being equal,
+ // we'd like more recent frames (less latency).
+ unsigned dropped_frames = 0;
+ while (queue_length > card->queue_length_policy.get_safe_queue_length()) {
+ assert(!card->new_frames.empty());
+ assert(queue_length > card->new_frames.front().dropped_frames);
+ queue_length -= card->new_frames.front().dropped_frames;
+
+ if (queue_length <= card->queue_length_policy.get_safe_queue_length()) {
+ // No need to drop anything.
+ break;
+ }
+
+ card->new_frames.pop_front();
+ card->new_frames_changed.notify_all();
+ --queue_length;
+ ++dropped_frames;
+ }
+
+ if (dropped_frames > 0) {
+ fprintf(stderr, "Card %u dropped %u frame(s) to keep latency down.\n",
+ card_index, dropped_frames);
+ }
+}
+
+
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])
{
OutputFrameInfo output_frame_info;
for (unsigned card_index = 0; card_index < num_cards; ++card_index) {
CaptureCard *card = &cards[card_index];
- if (card->new_frames.empty()) {
- assert(!input_card_is_master_clock(card_index, master_card_index));
- card->queue_length_policy.update_policy(-1);
- continue;
- }
- new_frames[card_index] = move(card->new_frames.front());
- has_new_frame[card_index] = true;
- card->new_frames.pop();
- card->new_frames_changed.notify_all();
-
if (input_card_is_master_clock(card_index, master_card_index)) {
// We don't use the queue length policy for the master card,
// but we will if it stops being the master. Thus, clear out
// the policy in case we switch in the future.
card->queue_length_policy.reset(card_index);
+ assert(!card->new_frames.empty());
} else {
- // If we have excess frames compared to the policy for this card,
- // drop frames from the head.
- card->queue_length_policy.update_policy(card->new_frames.size());
- while (card->new_frames.size() > card->queue_length_policy.get_safe_queue_length()) {
- card->new_frames.pop();
- }
+ trim_queue(card, card_index);
+ }
+ if (!card->new_frames.empty()) {
+ new_frames[card_index] = move(card->new_frames.front());
+ has_new_frame[card_index] = true;
+ card->new_frames.pop_front();
+ card->new_frames_changed.notify_all();
}
}
last_mode_scan_change[card_index] = steady_clock::now();
}
+map<uint32_t, bmusb::VideoMode> Mixer::get_available_output_video_modes() const
+{
+ assert(desired_output_card_index != -1);
+ unique_lock<mutex> lock(card_mutex);
+ return cards[desired_output_card_index].output->get_available_video_modes();
+}
+
Mixer::OutputChannel::~OutputChannel()
{
if (has_current_frame) {
projects / nageru / blobdiff