Fix an issue where the mixer lagging too much behind CEF would cause us to display...

[nageru] / resampling_queue.cpp

diff --git a/resampling_queue.cpp b/resampling_queue.cpp
index 188bf7d2d57ccdb98f249f86c59e0360e65b470b..24811ebe5bbab43fa7cd68471c4ca69f82e673e8 100644 (file)
--- a/resampling_queue.cpp
+++ b/resampling_queue.cpp
@@ -77,6 +77,11 @@ bool ResamplingQueue::get_output_samples(steady_clock::time_point ts, float *sam
                return true;
        }
 
+       // This can happen when we get dropped frames on the master card.
+       if (duration<double>(ts.time_since_epoch()).count() <= 0.0) {
+               rate_adjustment_policy = DO_NOT_ADJUST_RATE;
+       }
+
        if (rate_adjustment_policy == ADJUST_RATE && (a0.good_sample || a1.good_sample)) {
                // Estimate the current number of input samples produced at
                // this instant in time, by extrapolating from the last known
@@ -93,15 +98,22 @@ bool ResamplingQueue::get_output_samples(steady_clock::time_point ts, float *sam
                double actual_delay = input_samples_received - input_samples_consumed;
                actual_delay += vresampler.inpdist();    // Delay in the resampler itself.
                double err = actual_delay - expected_delay;
-               if (first_output && err < 0.0) {
+               if (first_output) {
                        // Before the very first block, insert artificial delay based on our initial estimate,
                        // so that we don't need a long period to stabilize at the beginning.
-                       int delay_samples_to_add = lrintf(-err);
-                       for (ssize_t i = 0; i < delay_samples_to_add * num_channels; ++i) {
-                               buffer.push_front(0.0f);
+                       if (err < 0.0) {
+                               int delay_samples_to_add = lrintf(-err);
+                               for (ssize_t i = 0; i < delay_samples_to_add * num_channels; ++i) {
+                                       buffer.push_front(0.0f);
+                               }
+                               total_consumed_samples -= delay_samples_to_add;  // Equivalent to increasing input_samples_received on a0 and a1.
+                               err += delay_samples_to_add;
+                       } else if (err > 0.0) {
+                               int delay_samples_to_remove = min<int>(lrintf(err), buffer.size() / num_channels);
+                               buffer.erase(buffer.begin(), buffer.begin() + delay_samples_to_remove * num_channels);
+                               total_consumed_samples += delay_samples_to_remove;
+                               err -= delay_samples_to_remove;
                        }
-                       total_consumed_samples -= delay_samples_to_add;  // Equivalent to increasing input_samples_received on a0 and a1.
-                       err += delay_samples_to_add;
                }
                first_output = false;
 
@@ -136,8 +148,6 @@ bool ResamplingQueue::get_output_samples(steady_clock::time_point ts, float *sam
                if (rcorr < 0.95) rcorr = 0.95;
                assert(!isnan(rcorr));
                vresampler.set_rratio(rcorr);
-       } else {
-               assert(rate_adjustment_policy == DO_NOT_ADJUST_RATE);
        }
 
        // Finally actually resample, producing exactly <num_samples> output samples.
@@ -150,6 +160,10 @@ bool ResamplingQueue::get_output_samples(steady_clock::time_point ts, float *sam
                        fprintf(stderr, "Card %u: PANIC: Out of input samples to resample, still need %d output samples! (correction factor is %f)\n",
                                card_num, int(vresampler.out_count), rcorr);
                        memset(vresampler.out_data, 0, vresampler.out_count * num_channels * sizeof(float));
+
+                       // Reset the loop filter.
+                       z1 = z2 = z3 = 0.0;
+
                        return false;
                }