From fd72e351b88bc572ef60870e030b5d61c7fca53b Mon Sep 17 00:00:00 2001
From: Mariotaku <mariotaku.lee@gmail.com>
Date: Tue, 16 Apr 2024 00:32:19 +0900
Subject: [PATCH] supports custom surround params

---
 src/audio.cpp   | 10 ++++++++++
 src/audio.h     |  4 ++++
 src/nvhttp.cpp  |  1 +
 src/process.cpp |  1 +
 src/rtsp.cpp    | 29 +++++++++++++++++++++++++++++
 src/rtsp.h      |  1 +
 6 files changed, 46 insertions(+)

diff --git a/src/audio.cpp b/src/audio.cpp
index 1995e380ea7..5e64f1ed57c 100644
--- a/src/audio.cpp
+++ b/src/audio.cpp
@@ -99,6 +99,10 @@ namespace audio {
   encodeThread(sample_queue_t samples, config_t config, void *channel_data) {
     auto packets = mail::man->queue<packet_t>(mail::audio_packets);
     auto stream = &stream_configs[map_stream(config.channels, config.flags[config_t::HIGH_QUALITY])];
+    if (config.flags[config_t::CUSTOM_SURROUND_PARAMS]) {
+      // sampleRate and bitrate are already updated in capture function
+      stream = &config.customStreamConfig;
+    }
 
     // Encoding takes place on this thread
     platf::adjust_thread_priority(platf::thread_priority_e::high);
@@ -136,6 +140,12 @@ namespace audio {
   capture(safe::mail_t mail, config_t config, void *channel_data) {
     auto shutdown_event = mail->event<bool>(mail::shutdown);
     auto stream = &stream_configs[map_stream(config.channels, config.flags[config_t::HIGH_QUALITY])];
+    if (config.flags[config_t::CUSTOM_SURROUND_PARAMS]) {
+      auto orig = stream;
+      stream = &config.customStreamConfig;
+      stream->sampleRate = orig->sampleRate;
+      stream->bitrate = orig->bitrate;
+    }
 
     auto ref = control_shared.ref();
     if (!ref) {
diff --git a/src/audio.h b/src/audio.h
index fe22c94611d..9449f9474b2 100644
--- a/src/audio.h
+++ b/src/audio.h
@@ -32,6 +32,7 @@ namespace audio {
     enum flags_e : int {
       HIGH_QUALITY,
       HOST_AUDIO,
+      CUSTOM_SURROUND_PARAMS,
       MAX_FLAGS
     };
 
@@ -39,6 +40,9 @@ namespace audio {
     int channels;
     int mask;
 
+    std::uint8_t customStreamMapping[8];
+    opus_stream_config_t customStreamConfig;
+
     std::bitset<MAX_FLAGS> flags;
   };
 
diff --git a/src/nvhttp.cpp b/src/nvhttp.cpp
index 695820f4b3a..670bc3f2e48 100644
--- a/src/nvhttp.cpp
+++ b/src/nvhttp.cpp
@@ -296,6 +296,7 @@ namespace nvhttp {
     launch_session->appid = util::from_view(get_arg(args, "appid", "unknown"));
     launch_session->enable_sops = util::from_view(get_arg(args, "sops", "0"));
     launch_session->surround_info = util::from_view(get_arg(args, "surroundAudioInfo", "196610"));
+    launch_session->surround_params = (get_arg(args, "surroundParams", ""));
     launch_session->gcmap = util::from_view(get_arg(args, "gcmap", "0"));
     launch_session->enable_hdr = util::from_view(get_arg(args, "hdrMode", "0"));
 
diff --git a/src/process.cpp b/src/process.cpp
index 89dc4dc5ae5..32af14ebd9d 100644
--- a/src/process.cpp
+++ b/src/process.cpp
@@ -185,6 +185,7 @@ namespace proc {
         _env["SUNSHINE_CLIENT_AUDIO_CONFIGURATION"] = "7.1";
         break;
     }
+    _env["SUNSHINE_CLIENT_AUDIO_SURROUND_PARAMS"] = launch_session->surround_params;
 
     if (!_app.output.empty() && _app.output != "null"sv) {
 #ifdef _WIN32
diff --git a/src/rtsp.cpp b/src/rtsp.cpp
index 0180fbee37a..b860218ae86 100644
--- a/src/rtsp.cpp
+++ b/src/rtsp.cpp
@@ -818,6 +818,12 @@ namespace rtsp_stream {
       ss << "a=rtpmap:98 AV1/90000"sv << std::endl;
     }
 
+    if (!session.surround_params.empty()) {
+      // If we have our own surround parameters, advertise them twice first
+      ss << "a=fmtp:97 surround-params="sv << session.surround_params << std::endl;
+      ss << "a=fmtp:97 surround-params="sv << session.surround_params << std::endl;
+    }
+
     for (int x = 0; x < audio::MAX_STREAM_CONFIG; ++x) {
       auto &stream_config = audio::stream_configs[x];
       std::uint8_t mapping[platf::speaker::MAX_SPEAKERS];
@@ -1031,6 +1037,29 @@ namespace rtsp_stream {
           config.audio.flags[audio::config_t::HIGH_QUALITY] = (content.find("0.0.0.0"sv) == std::string::npos);
         }
       }
+    } else if (session.surround_params.length() > 3) {
+      // Channels
+      std::uint8_t c = session.surround_params[0] - '0';
+      // Streams
+      std::uint8_t n = session.surround_params[1] - '0';
+      // Coupled streams
+      std::uint8_t m = session.surround_params[2] - '0';
+      auto valid = false;
+      if ((c == 6 || c == 8) && c == config.audio.channels && n + m == c && session.surround_params.length() == c + 3) {
+        config.audio.customStreamConfig.channelCount = c;
+        config.audio.customStreamConfig.streams = n;
+        config.audio.customStreamConfig.coupledStreams = m;
+        config.audio.customStreamConfig.mapping = config.audio.customStreamMapping;
+        valid = true;
+        for (std::uint8_t i = 0; i < c; i++) {
+          config.audio.customStreamMapping[i] = session.surround_params[i + 3] - '0';
+          if (config.audio.customStreamMapping[i] >= c) {
+            valid = false;
+            break;
+          }
+        }
+      }
+      config.audio.flags[audio::config_t::CUSTOM_SURROUND_PARAMS] = valid;
     }
 
     // If the client sent a configured bitrate, we will choose the actual bitrate ourselves
diff --git a/src/rtsp.h b/src/rtsp.h
index 20bb8453998..16dba1e0592 100644
--- a/src/rtsp.h
+++ b/src/rtsp.h
@@ -29,6 +29,7 @@ namespace rtsp_stream {
     int gcmap;
     int appid;
     int surround_info;
+    std::string surround_params;
     bool enable_hdr;
     bool enable_sops;