add option to adjust audio sync

data/locale/en-US.ini

@@ -109,6 +109,8 @@ step_width="Step Width"
 step_gap="Step Gap"
 min_bar_height="Minimum Bar Height"
 
+audio_sync_offset="Audio Sync Offset"
+
 chan_desc="Graph separate L/R channels, mono mixdown, or individual channel."
 auto_fft_desc="Calculate FFT size based on FPS and sample rate. You probably don't want this. Retained for backwards compatibility."
 fft_desc="Larger values increase frequency resolution, but are more CPU intensive and increase latency."
@@ -128,3 +130,4 @@ mirror_desc="Reflect graph horizontally around the center."
 radial_arc_desc="Arc angle of radial display in degrees."
 ignore_mute_desc="Continue processing audio even when source is muted."
 lage_fft_desc="Allow large FFT sizes that may significantly increase latency and resource consumption."
+audio_sync_desc="Positive values delay visuals, negative values may not work depending on source."

src/settings.hpp

@@ -132,6 +132,7 @@ static inline bool p_equ(const char *s1, const char *s2) { return std::strcmp(s1
 #define P_STEP_GAP          "step_gap"
 #define P_MIN_BAR_HEIGHT    "min_bar_height"
 
+#define P_AUDIO_SYNC_OFFSET "audio_sync_offset"
 
 // tooltip descriptions
 #define P_CHAN_DESC         "chan_desc"
@@ -153,3 +154,4 @@ static inline bool p_equ(const char *s1, const char *s2) { return std::strcmp(s1
 #define P_RADIAL_ARC_DESC   "radial_arc_desc"
 #define P_IGNORE_MUTE_DESC  "ignore_mute_desc"
 #define P_LARGE_FFT_DESC    "lage_fft_desc"
+#define P_AUDIO_SYNC_DESC   "audio_sync_desc"

src/source.cpp

@@ -170,6 +170,7 @@ namespace callbacks {
         obs_data_set_default_bool(settings, P_NORMALIZE_VOLUME, false);
         obs_data_set_default_int(settings, P_VOLUME_TARGET, -8);
         obs_data_set_default_int(settings, P_MAX_GAIN, 30);
+        obs_data_set_default_int(settings, P_AUDIO_SYNC_OFFSET, 0);
     }
 
     static obs_properties_t *get_properties([[maybe_unused]] void *data)
@@ -190,6 +191,11 @@ namespace callbacks {
         for(const auto& str : enumerate_audio_sources())
             obs_property_list_add_string(srclist, str.c_str(), str.c_str());
 
+        // audio sync
+        auto audio_sync = obs_properties_add_int_slider(props, P_AUDIO_SYNC_OFFSET, T(P_AUDIO_SYNC_OFFSET), -1000, 1000, 10);
+        obs_property_int_set_suffix(audio_sync, " ms");
+        obs_property_set_long_description(audio_sync, T(P_AUDIO_SYNC_DESC));
+
         // hide on silent audio
         obs_properties_add_bool(props, P_HIDE_SILENT, T(P_HIDE_SILENT));
 
@@ -547,6 +553,7 @@ void WAVSource::get_settings(obs_data_t *settings)
     m_normalize_volume = obs_data_get_bool(settings, P_NORMALIZE_VOLUME);
     m_volume_target = (float)obs_data_get_int(settings, P_VOLUME_TARGET);
     m_max_gain = (float)obs_data_get_int(settings, P_MAX_GAIN);
+    m_ts_offset = (int64_t)obs_data_get_int(settings, P_AUDIO_SYNC_OFFSET) * 1000000ll;
 
     m_color_base = { {{(uint8_t)color_base / 255.0f, (uint8_t)(color_base >> 8) / 255.0f, (uint8_t)(color_base >> 16) / 255.0f, (uint8_t)(color_base >> 24) / 255.0f}} };
     m_color_middle = { {{(uint8_t)color_middle / 255.0f, (uint8_t)(color_middle >> 8) / 255.0f, (uint8_t)(color_middle >> 16) / 255.0f, (uint8_t)(color_middle >> 24) / 255.0f}} };

src/source.hpp

@@ -150,6 +150,7 @@ class WAVSource
     uint64_t m_capture_ts = 0;  // timestamp of last audio callback in nanoseconds
     uint64_t m_audio_ts = 0;    // timestamp of the end of available audio in nanoseconds
     uint64_t m_tick_ts = 0;     // timestamp of last 'tick' in nanoseconds
+    int64_t m_ts_offset = 0;    // audio sync offset in nanoseconds
 
     // settings
     RenderMode m_render_mode = RenderMode::SOLID;
@@ -270,9 +271,10 @@ class WAVSource
 
     int64_t get_audio_sync(uint64_t ts)     // get delta between end of available audio and given time in nanoseconds
     {
-        auto delta = std::max(m_audio_ts, ts) - std::min(m_audio_ts, ts);
+        auto audio_ts = m_audio_ts + m_ts_offset;
+        auto delta = std::max(audio_ts, ts) - std::min(audio_ts, ts);
         delta = std::min(delta, MAX_TS_DELTA);
-        return (m_audio_ts < ts) ? -(int64_t)delta : (int64_t)delta;
+        return (audio_ts < ts) ? -(int64_t)delta : (int64_t)delta;
     }
 
     // constants