Make it possible to override the level compressor with the gain staging knob.

[nageru] / mixer.cpp

diff --git a/mixer.cpp b/mixer.cpp
index dd8cc6013d72559bb08b89c6d5605953ac6b4269..72022026f771056e0211ccac874e69c8ee0ed22a 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -526,7 +526,7 @@ void Mixer::thread_func()
                }
 
                if (audio_level_callback != nullptr) {
-                       unique_lock<mutex> lock(r128_mutex);
+                       unique_lock<mutex> lock(compressor_mutex);
                        double loudness_s = r128.loudness_S();
                        double loudness_i = r128.integrated();
                        double loudness_range_low = r128.range_min();
@@ -534,7 +534,7 @@ void Mixer::thread_func()
 
                        audio_level_callback(loudness_s, 20.0 * log10(peak),
                                             loudness_i, loudness_range_low, loudness_range_high,
-                                            last_gain_staging_db);
+                                            gain_staging_db);
                }
 
                for (unsigned card_index = 1; card_index < num_cards; ++card_index) {
@@ -715,14 +715,23 @@ void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
        // then apply a makeup gain to get it to -14 dBFS. -14 dBFS is, of course,
        // entirely arbitrary, but from practical tests with speech, it seems to
        // put ut around -23 LUFS, so it's a reasonable starting point for later use.
-       if (level_compressor_enabled) {
-               float threshold = 0.01f;   // -40 dBFS.
-               float ratio = 20.0f;
-               float attack_time = 0.5f;
-               float release_time = 20.0f;
-               float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
-               level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
-               last_gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
+       {
+               unique_lock<mutex> lock(level_compressor_mutex);
+               if (level_compressor_enabled) {
+                       float threshold = 0.01f;   // -40 dBFS.
+                       float ratio = 20.0f;
+                       float attack_time = 0.5f;
+                       float release_time = 20.0f;
+                       float makeup_gain = pow(10.0f, (ref_level_dbfs - (-40.0f)) / 20.0f);  // +26 dB.
+                       level_compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
+                       gain_staging_db = 20.0 * log10(level_compressor.get_attenuation() * makeup_gain);
+               } else {
+                       // Just apply the gain we already had.
+                       float g = pow(10.0f, gain_staging_db / 20.0f);
+                       for (size_t i = 0; i < samples_out.size(); ++i) {
+                               samples_out[i] *= g;
+                       }
+               }
        }
 
 #if 0
@@ -778,7 +787,7 @@ void Mixer::process_audio_one_frame(int64_t frame_pts_int, int num_samples)
        deinterleave_samples(samples_out, &left, &right);
        float *ptrs[] = { left.data(), right.data() };
        {
-               unique_lock<mutex> lock(r128_mutex);
+               unique_lock<mutex> lock(compressor_mutex);
                r128.process(left.size(), ptrs);
        }