auhal: add kAudioStreamPropertyLatency to the latency

Fixes delay with AirPlay devices.

Internal and bluetooth devices have a valid Device Latency.
Airplay 2 devices has a valid Stream Latency.

modules/audio_output/auhal.c

@@ -1482,7 +1482,7 @@ GetLatency(audio_output_t *p_aout, const audio_sample_format_t *fmt)
     aout_sys_t *p_sys = p_aout->sys;
 
     UInt32 i_latency_samples;
-    vlc_tick_t i_latency_us, i_device_latency_us = 0;
+    vlc_tick_t i_latency_us, i_device_latency_us = 0, i_stream_latency_us = 0;
     /* Get device latency */
     int ret = AO_GET1PROP(p_sys->i_selected_dev, UInt32, &i_latency_samples,
                           kAudioDevicePropertyLatency,
@@ -1492,10 +1492,28 @@ GetLatency(audio_output_t *p_aout, const audio_sample_format_t *fmt)
     else
         msg_Warn(p_aout, "failed to get kAudioDevicePropertyLatency");
 
-    i_latency_us = i_device_latency_us;
+    AudioStreamID sid;
+    /* Get stream latency */
+    ret = AO_GET1PROP(p_sys->i_selected_dev, AudioStreamID, &sid,
+                      kAudioDevicePropertyStreams, kAudioObjectPropertyScopeOutput);
+    if (ret == VLC_SUCCESS)
+    {
+        ret = AO_GET1PROP(sid, UInt32, &i_latency_samples,
+                          kAudioStreamPropertyLatency,
+                          kAudioObjectPropertyScopeOutput);
+        if (ret == VLC_SUCCESS)
+            i_stream_latency_us = vlc_tick_from_samples(i_latency_samples, fmt->i_rate);
+        else
+            msg_Warn(p_aout, "failed to get kAudioStreamPropertyLatency");
+    }
+    else
+        msg_Warn(p_aout, "failed to get kAudioDevicePropertyStreams");
+
+    i_latency_us = i_device_latency_us + i_stream_latency_us;
 
-    msg_Dbg(p_aout, "Current device has a latency of " PRId64 " us",
-            i_latency_us);
+    msg_Dbg(p_aout, "Current device has a latency of %" PRId64 " us "
+            "(device: %" PRId64 " us, stream: %" PRId64 " us)", i_latency_us,
+            i_device_latency_us, i_stream_latency_us);
 
     return i_latency_us;
 }