From 4a25f3e53bdac8c2510cc1c7f06e479a17a42e6b Mon Sep 17 00:00:00 2001
From: Romain Vimont <rom@rom1v.com>
Date: Wed, 8 Mar 2023 20:13:08 +0100
Subject: [PATCH] Print info logs to stdout

All server logs were printed to stdout, while all client logs were
printed to stderr.

Instead, use stderr for warnings and errors, stdout for the others:
 - stdout: verbose, debug, info
 - stderr: warn, error
---
 app/src/util/log.c                            | 22 +++++++++++++++++++
 .../main/java/com/genymobile/scrcpy/Ln.java   |  4 ++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/app/src/util/log.c b/app/src/util/log.c
index 25b1f26e..0975e54a 100644
--- a/app/src/util/log.c
+++ b/app/src/util/log.c
@@ -125,8 +125,30 @@ sc_av_log_callback(void *avcl, int level, const char *fmt, va_list vl) {
     free(local_fmt);
 }
 
+static const char *const sc_sdl_log_priority_names[SDL_NUM_LOG_PRIORITIES] = {
+    [SDL_LOG_PRIORITY_VERBOSE] = "VERBOSE",
+    [SDL_LOG_PRIORITY_DEBUG] = "DEBUG",
+    [SDL_LOG_PRIORITY_INFO] = "INFO",
+    [SDL_LOG_PRIORITY_WARN] = "WARN",
+    [SDL_LOG_PRIORITY_ERROR] = "ERROR",
+    [SDL_LOG_PRIORITY_CRITICAL] = "CRITICAL",
+};
+
+static void SDLCALL
+sc_sdl_log_print(void *userdata, int category, SDL_LogPriority priority,
+                 const char *message) {
+    (void) userdata;
+    (void) category;
+
+    FILE *out = priority < SDL_LOG_PRIORITY_WARN ? stdout : stderr;
+    assert(priority < SDL_NUM_LOG_PRIORITIES);
+    const char *prio_name = sc_sdl_log_priority_names[priority];
+    fprintf(out, "%s: %s\n", prio_name, message);
+}
+
 void
 sc_log_configure() {
+    SDL_LogSetOutputFunction(sc_sdl_log_print, NULL);
     // Redirect FFmpeg logs to SDL logs
     av_log_set_callback(sc_av_log_callback);
 }
diff --git a/server/src/main/java/com/genymobile/scrcpy/Ln.java b/server/src/main/java/com/genymobile/scrcpy/Ln.java
index 291f26ff..199c29be 100644
--- a/server/src/main/java/com/genymobile/scrcpy/Ln.java
+++ b/server/src/main/java/com/genymobile/scrcpy/Ln.java
@@ -60,7 +60,7 @@ public final class Ln {
     public static void w(String message, Throwable throwable) {
         if (isEnabled(Level.WARN)) {
             Log.w(TAG, message, throwable);
-            System.out.print(PREFIX + "WARN: " + message + '\n');
+            System.err.print(PREFIX + "WARN: " + message + '\n');
             if (throwable != null) {
                 throwable.printStackTrace();
             }
@@ -74,7 +74,7 @@ public final class Ln {
     public static void e(String message, Throwable throwable) {
         if (isEnabled(Level.ERROR)) {
             Log.e(TAG, message, throwable);
-            System.out.print(PREFIX + "ERROR: " + message + "\n");
+            System.err.print(PREFIX + "ERROR: " + message + "\n");
             if (throwable != null) {
                 throwable.printStackTrace();
             }