From 0767e00b9dd95619fb03e923652527b008813188 Mon Sep 17 00:00:00 2001
From: Andy Grundman <andy@hybridized.org>
Date: Fri, 10 Jan 2025 04:35:15 -0500
Subject: [PATCH] fix(rtp) attempt at using the pu64QPCPosition packet capture
 timestamp value from Windows GetBuffer(), but didn't quite figure out the way
 to pass it in the packet queue

---
 src/audio.h                    |  2 ++
 src/platform/windows/audio.cpp |  6 +++++-
 src/stream.cpp                 | 13 +++++++++++--
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/src/audio.h b/src/audio.h
index 927dfdef20b..d28c50fcd44 100644
--- a/src/audio.h
+++ b/src/audio.h
@@ -69,6 +69,8 @@ namespace audio {
 
   using buffer_t = util::buffer_t<std::uint8_t>;
   using packet_t = std::pair<void *, buffer_t>;
+  // XXX maybe change to this for adding packet_timestamp
+  // using packet_t = std::tuple<void *, buffer_t, std::uint64_t>;
   using audio_ctx_ref_t = safe::shared_t<audio_ctx_t>::ptr_t;
 
   void
diff --git a/src/platform/windows/audio.cpp b/src/platform/windows/audio.cpp
index 3c401976afc..74fdfdd6fd9 100644
--- a/src/platform/windows/audio.cpp
+++ b/src/platform/windows/audio.cpp
@@ -572,6 +572,7 @@ namespace platf::audio {
       // number of samples / number of channels
       struct block_aligned_t {
         std::uint32_t audio_sample_size;
+        std::uint64_t packet_timestamp;
       } block_aligned;
 
       // Check if the default audio device has changed
@@ -606,7 +607,8 @@ namespace platf::audio {
           (BYTE **) &sample_aligned.samples,
           &block_aligned.audio_sample_size,
           &buffer_flags,
-          nullptr, nullptr);
+          nullptr,
+          &block_aligned.packet_timestamp);
 
         switch (status) {
           case S_OK:
@@ -637,6 +639,7 @@ namespace platf::audio {
         }
 
         sample_buf_pos += n;
+        packet_timestamp = block_aligned.packet_timestamp;
 
         audio_capture->ReleaseBuffer(block_aligned.audio_sample_size);
       }
@@ -668,6 +671,7 @@ namespace platf::audio {
     util::buffer_t<float> sample_buf;
     float *sample_buf_pos;
     int channels;
+    std::uint64_t packet_timestamp;
 
     HANDLE mmcss_task_handle = NULL;
   };
diff --git a/src/stream.cpp b/src/stream.cpp
index 953342cd0f9..991a76a9022 100644
--- a/src/stream.cpp
+++ b/src/stream.cpp
@@ -1631,14 +1631,23 @@ namespace stream {
       }
 
       TUPLE_2D_REF(channel_data, packet_data, *packet);
+      // XXX for transporting packet_timestamp?
+      // TUPLE_3D_REF(channel_data, packet_data, packet_timestamp, *packet);
       auto session = (session_t *) channel_data;
 
       auto sequenceNumber = session->audio.sequenceNumber;
       // Audio timestamps are in milliseconds and should be AudioPacketDuration (5ms or 10ms) apart
+
+      // XXX fix packet->packet_timestamp
+      // auto packet_time_point = std::chrono::steady_clock::time_point(
+      //   std::chrono::microseconds(packet->packet_timestamp)
+      // );
+
       auto timestamp = static_cast<std::uint32_t>(
-        std::chrono::duration_cast<std::chrono::microseconds>(
+        std::chrono::duration_cast<std::chrono::milliseconds>(
+          // std::chrono::steady_clock::now() - packet_time_point
           std::chrono::steady_clock::now() - session->audio.timestamp_epoch
-        ).count() / 1000.0
+        ).count()
       );
 
       *(std::uint32_t *) iv.data() = util::endian::big<std::uint32_t>(session->audio.avRiKeyId + sequenceNumber);