Make it possible to choose which card is the master clock.

[nageru] / mixer.cpp

diff --git a/mixer.cpp b/mixer.cpp
index 50c93e8c018a9f3b077830b77788f8dffbee5b8c..2802329b136c60c69b9f760ce812150bb7fa49a7 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -605,8 +605,9 @@ void Mixer::thread_func()
                bool has_new_frame[MAX_CARDS] = { false };
                int num_samples[MAX_CARDS] = { 0 };
 
-               // TODO: Make configurable, and with a timeout.
-               unsigned master_card_index = 0;
+               // TODO: Add a timeout.
+               unsigned master_card_index = theme->map_signal(master_clock_channel);
+               assert(master_card_index < num_cards);
 
                get_one_frame_from_each_card(master_card_index, new_frames, has_new_frame, num_samples);
                schedule_audio_resampling_tasks(new_frames[master_card_index].dropped_frames, num_samples[master_card_index], new_frames[master_card_index].length);
@@ -715,7 +716,12 @@ void Mixer::get_one_frame_from_each_card(unsigned master_card_index, CaptureCard
                card->fractional_samples = num_samples_times_timebase % TIMEBASE;
                assert(num_samples[card_index] >= 0);
 
-               if (card_index != master_card_index) {
+               if (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);
+               } 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());