From ac99bff18e0033075eaa98b1c1e2d9be8c98b425 Mon Sep 17 00:00:00 2001
From: Misaki Kasumi <misakikasumi@outlook.com>
Date: Fri, 22 Mar 2024 02:03:42 +0800
Subject: [PATCH] ao_avfoundation: add jitter check

---
 audio/out/ao_avfoundation.m | 21 ++++++++++++---------
 1 file changed, 12 insertions(+), 9 deletions(-)

diff --git a/audio/out/ao_avfoundation.m b/audio/out/ao_avfoundation.m
index e30d4c15a47f3..581fc788bda10 100644
--- a/audio/out/ao_avfoundation.m
+++ b/audio/out/ao_avfoundation.m
@@ -65,11 +65,14 @@ static void feed(struct ao *ao)
     CMBlockBufferRef block_buffer = NULL;
     CMSampleBufferRef sample_buffer = NULL;
 
-    if (p->end_time_mp == -1) {
-        p->end_time_mp = mp_time_ns();
-    }
-    if (p->end_time_av == -1) {
-        p->end_time_av = CMTimeGetNanoseconds([p->synchronizer currentTime]);
+    int64_t time_mp = mp_time_ns();
+    int64_t time_av = CMTimeGetNanoseconds([p->synchronizer currentTime]);
+    int64_t end_time_mp = p->end_time_mp == -1 ? time_mp : p->end_time_mp;
+    int64_t end_time_av = p->end_time_av == -1 ? time_av : p->end_time_av;
+    int64_t diff = (time_mp - time_av) - (end_time_mp - end_time_av);
+    if (diff > 1000000 || diff < -1000000) {
+        MP_WARN(ao, "timestamps mismatch; restarting");
+        goto error;
     }
 
     int request_sample_count = ao->samplerate / 10; // 1/10 samplerate may be a good number
@@ -94,7 +97,7 @@ static void feed(struct ao *ao)
         goto error;
     }
 
-    int real_sample_count = ao_read_data_nonblocking(ao, data, request_sample_count, p->end_time_mp);
+    int real_sample_count = ao_read_data_nonblocking(ao, data, request_sample_count, end_time_mp);
     if (real_sample_count == 0) {
         CFRelease(block_buffer);
         block_buffer = NULL;
@@ -104,7 +107,7 @@ static void feed(struct ao *ao)
 
     CMSampleTimingInfo sample_timing_into[] = {(CMSampleTimingInfo) {
         .duration = CMTimeMake(1, ao->samplerate),
-        .presentationTimeStamp = CMTimeFromNanoseconds(p->end_time_av),
+        .presentationTimeStamp = CMTimeFromNanoseconds(end_time_av),
         .decodeTimeStamp = kCMTimeInvalid
     }};
     size_t sample_size_array[] = {ao->sstride};
@@ -130,8 +133,8 @@ static void feed(struct ao *ao)
     sample_buffer = NULL;
 
     int64_t delta = CMTimeGetNanoseconds(CMTimeMake(real_sample_count, ao->samplerate));
-    p->end_time_mp += delta;
-    p->end_time_av += delta;
+    p->end_time_mp = end_time_mp + delta;
+    p->end_time_av = end_time_av + delta;
 
     return;