Rework the audio/video sync algorithm.

[nageru] / audio_mixer.cpp

diff --git a/audio_mixer.cpp b/audio_mixer.cpp
index 01fed687b47a8d2ae77a752896f925d11c176c37..e4d95a49422250e44dced2a84f11dc866ac878f6 100644 (file)
--- a/audio_mixer.cpp
+++ b/audio_mixer.cpp
@@ -25,6 +25,7 @@
 
 using namespace bmusb;
 using namespace std;
+using namespace std::chrono;
 using namespace std::placeholders;
 
 namespace {
@@ -231,10 +232,9 @@ void AudioMixer::reset_resampler_mutex_held(DeviceSpec device_spec)
                        device_spec.index, device->capture_frequency, OUTPUT_FREQUENCY, device->interesting_channels.size(),
                        global_flags.audio_queue_length_ms * 0.001));
        }
-       device->next_local_pts = 0;
 }
 
-bool AudioMixer::add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, AudioFormat audio_format, int64_t frame_length)
+bool AudioMixer::add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned num_samples, AudioFormat audio_format, int64_t frame_length, steady_clock::time_point frame_time)
 {
        AudioDevice *device = find_audio_device(device_spec);
 
@@ -274,9 +274,7 @@ bool AudioMixer::add_audio(DeviceSpec device_spec, const uint8_t *data, unsigned
        }
 
        // Now add it.
-       int64_t local_pts = device->next_local_pts;
-       device->resampling_queue->add_input_samples(local_pts / double(TIMEBASE), audio.get(), num_samples);
-       device->next_local_pts = local_pts + frame_length;
+       device->resampling_queue->add_input_samples(frame_time, audio.get(), num_samples, ResamplingQueue::ADJUST_RATE);
        return true;
 }
 
@@ -298,11 +296,7 @@ bool AudioMixer::add_silence(DeviceSpec device_spec, unsigned samples_per_frame,
 
        vector<float> silence(samples_per_frame * num_channels, 0.0f);
        for (unsigned i = 0; i < num_frames; ++i) {
-               device->resampling_queue->add_input_samples(device->next_local_pts / double(TIMEBASE), silence.data(), samples_per_frame);
-               // Note that if the format changed in the meantime, we have
-               // no way of detecting that; we just have to assume the frame length
-               // is always the same.
-               device->next_local_pts += frame_length;
+               device->resampling_queue->add_input_samples(steady_clock::now(), silence.data(), samples_per_frame, ResamplingQueue::DO_NOT_ADJUST_RATE);
        }
        return true;
 }
@@ -475,7 +469,7 @@ void apply_gain(float db, float last_db, vector<float> *samples)
 
 }  // namespace
 
-vector<float> AudioMixer::get_output(double pts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy)
+vector<float> AudioMixer::get_output(steady_clock::time_point ts, unsigned num_samples, ResamplingQueue::RateAdjustmentPolicy rate_adjustment_policy)
 {
        map<DeviceSpec, vector<float>> samples_card;
        vector<float> samples_bus;
@@ -490,7 +484,7 @@ vector<float> AudioMixer::get_output(double pts, unsigned num_samples, Resamplin
                        memset(&samples_card[device_spec][0], 0, samples_card[device_spec].size() * sizeof(float));
                } else {
                        device->resampling_queue->get_output_samples(
-                               pts,
+                               ts,
                                &samples_card[device_spec][0],
                                num_samples,
                                rate_adjustment_policy);