Move FFmpeg callback initialization

Configure FFmpeg log redirection on start from a log helper.

app/src/main.c

@@ -75,6 +75,8 @@ main_scrcpy(int argc, char *argv[]) {
         return SCRCPY_EXIT_FAILURE;
     }
 
+    sc_log_configure();
+
 #ifdef HAVE_USB
     enum scrcpy_exit_code ret = args.opts.otg ? scrcpy_otg(&args.opts)
                                               : scrcpy(&args.opts);

app/src/scrcpy.c

@@ -198,43 +198,6 @@ await_for_server(bool *connected) {
     return false;
 }
 
-static SDL_LogPriority
-sdl_priority_from_av_level(int level) {
-    switch (level) {
-        case AV_LOG_PANIC:
-        case AV_LOG_FATAL:
-            return SDL_LOG_PRIORITY_CRITICAL;
-        case AV_LOG_ERROR:
-            return SDL_LOG_PRIORITY_ERROR;
-        case AV_LOG_WARNING:
-            return SDL_LOG_PRIORITY_WARN;
-        case AV_LOG_INFO:
-            return SDL_LOG_PRIORITY_INFO;
-    }
-    // do not forward others, which are too verbose
-    return 0;
-}
-
-static void
-av_log_callback(void *avcl, int level, const char *fmt, va_list vl) {
-    (void) avcl;
-    SDL_LogPriority priority = sdl_priority_from_av_level(level);
-    if (priority == 0) {
-        return;
-    }
-
-    size_t fmt_len = strlen(fmt);
-    char *local_fmt = malloc(fmt_len + 10);
-    if (!local_fmt) {
-        LOG_OOM();
-        return;
-    }
-    memcpy(local_fmt, "[FFmpeg] ", 9); // do not write the final '\0'
-    memcpy(local_fmt + 9, fmt, fmt_len + 1); // include '\0'
-    SDL_LogMessageV(SDL_LOG_CATEGORY_VIDEO, priority, local_fmt, vl);
-    free(local_fmt);
-}
-
 static void
 sc_demuxer_on_ended(struct sc_demuxer *demuxer, bool eos, void *userdata) {
     (void) demuxer;
@@ -426,8 +389,6 @@ scrcpy(struct scrcpy_options *options) {
         recorder_initialized = true;
     }
 
-    av_log_set_callback(av_log_callback);
-
     static const struct sc_demuxer_callbacks demuxer_cbs = {
         .on_ended = sc_demuxer_on_ended,
     };

app/src/util/log.c

@@ -4,6 +4,7 @@
 # include <windows.h>
 #endif
 #include <assert.h>
+#include <libavformat/avformat.h>
 
 static SDL_LogPriority
 log_level_sc_to_sdl(enum sc_log_level level) {
@@ -85,3 +86,46 @@ sc_log_windows_error(const char *prefix, int error) {
     return true;
 }
 #endif
+
+static SDL_LogPriority
+sdl_priority_from_av_level(int level) {
+    switch (level) {
+        case AV_LOG_PANIC:
+        case AV_LOG_FATAL:
+            return SDL_LOG_PRIORITY_CRITICAL;
+        case AV_LOG_ERROR:
+            return SDL_LOG_PRIORITY_ERROR;
+        case AV_LOG_WARNING:
+            return SDL_LOG_PRIORITY_WARN;
+        case AV_LOG_INFO:
+            return SDL_LOG_PRIORITY_INFO;
+    }
+    // do not forward others, which are too verbose
+    return 0;
+}
+
+static void
+sc_av_log_callback(void *avcl, int level, const char *fmt, va_list vl) {
+    (void) avcl;
+    SDL_LogPriority priority = sdl_priority_from_av_level(level);
+    if (priority == 0) {
+        return;
+    }
+
+    size_t fmt_len = strlen(fmt);
+    char *local_fmt = malloc(fmt_len + 10);
+    if (!local_fmt) {
+        LOG_OOM();
+        return;
+    }
+    memcpy(local_fmt, "[FFmpeg] ", 9); // do not write the final '\0'
+    memcpy(local_fmt + 9, fmt, fmt_len + 1); // include '\0'
+    SDL_LogMessageV(SDL_LOG_CATEGORY_VIDEO, priority, local_fmt, vl);
+    free(local_fmt);
+}
+
+void
+sc_log_configure() {
+    // Redirect FFmpeg logs to SDL logs
+    av_log_set_callback(sc_av_log_callback);
+}

app/src/util/log.h

@@ -35,4 +35,7 @@ bool
 sc_log_windows_error(const char *prefix, int error);
 #endif
 
+void
+sc_log_configure();
+
 #endif