[logging] Made FFmpeg logging callback thread-safe by using thread-local storage...

diff --git a/modules/ffmpeg/ffmpeg.cpp b/modules/ffmpeg/ffmpeg.cpp
index cece1f6bfebf89e1b3aa0014db9f3a644783d223..ea7f73741497bcdfca2ec604e7d13e6ebac29c64 100644 (file)
--- a/modules/ffmpeg/ffmpeg.cpp
+++ b/modules/ffmpeg/ffmpeg.cpp
@@ -109,7 +109,15 @@ static void sanitize(uint8_t *line)
 
 void log_callback(void* ptr, int level, const char* fmt, va_list vl)
 {
-       static int print_prefix=1;
+       static boost::thread_specific_ptr<bool> print_prefix_tss;
+       auto print_prefix = print_prefix_tss.get();
+
+       if (!print_prefix)
+       {
+               print_prefix = new bool(true);
+               print_prefix_tss.reset(print_prefix);
+       }
+
        char line[1024];
        AVClass* avc= ptr ? *(AVClass**)ptr : NULL;
        if (level > AV_LOG_DEBUG)
@@ -117,7 +125,7 @@ void log_callback(void* ptr, int level, const char* fmt, va_list vl)
        line[0]=0;
 
 #undef fprintf
-       if(print_prefix && avc)
+       if(*print_prefix && avc)
        {
                if (avc->parent_log_context_offset)
                {
@@ -130,7 +138,7 @@ void log_callback(void* ptr, int level, const char* fmt, va_list vl)
 
        std::vsnprintf(line + strlen(line), sizeof(line) - strlen(line), fmt, vl);
 
-       print_prefix = strlen(line) && line[strlen(line)-1] == '\n';
+       *print_prefix = strlen(line) && line[strlen(line)-1] == '\n';
 
        sanitize((uint8_t*)line);