Tweak the limiter a bit.

[nageru] / mixer.cpp

diff --git a/mixer.cpp b/mixer.cpp
index 656cdfaf39feb9ef67b79464fffacde678c2e5c1..08c562f7ab448250ba36f48e48b4805f01edc707 100644 (file)
--- a/mixer.cpp
+++ b/mixer.cpp
@@ -575,10 +575,12 @@ void Mixer::process_audio_one_frame()
 //     float limiter_att, compressor_att;
 
        // Then a limiter at +0 dB (so, -14 dBFS) to take out the worst peaks only.
+       // Note that since ratio is not infinite, we could go slightly higher than this.
+       // Probably more tuning is warranted here.
        {
                float threshold = pow(10.0f, (ref_level_dbfs + 0.0f) / 20.0f);  // +0 dB.
-               float ratio = 1000.0f;  // Infinity.
-               float attack_time = 0.001f;
+               float ratio = 30.0f;
+               float attack_time = 0.0f;  // Instant.
                float release_time = 0.005f;
                float makeup_gain = 1.0f;  // 0 dB.
                limiter.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
@@ -591,7 +593,7 @@ void Mixer::process_audio_one_frame()
                float ratio = 20.0f;
                float attack_time = 0.005f;
                float release_time = 0.040f;
-               float makeup_gain = 2.0f;  // +3 dB.
+               float makeup_gain = 2.0f;  // +6 dB.
                compressor.process(samples_out.data(), samples_out.size() / 2, threshold, ratio, attack_time, release_time, makeup_gain);
 //             compressor_att = compressor.get_attenuation();
        }
@@ -599,7 +601,7 @@ void Mixer::process_audio_one_frame()
 //     printf("limiter=%+5.1f  compressor=%+5.1f\n", 20.0*log10(limiter_att), 20.0*log10(compressor_att));
 
        // Find peak and R128 levels.
-       peak = std::max(peak, find_peak(samples_out));
+       peak = max<float>(peak, find_peak(samples_out));
        vector<float> left, right;
        deinterleave_samples(samples_out, &left, &right);
        float *ptrs[] = { left.data(), right.data() };
@@ -694,6 +696,13 @@ void Mixer::channel_clicked(int preview_num)
        theme->channel_clicked(preview_num);
 }
 
+void Mixer::reset_meters()
+{
+       peak = 0.0f;
+       r128.reset();
+       r128.integr_start();
+}
+
 Mixer::OutputChannel::~OutputChannel()
 {
        if (has_current_frame) {