av_cpu_count: factorize "detected %d logical cores" message

Also print the message just once
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/pthread.c

@@ -790,7 +790,6 @@ static int frame_thread_init(AVCodecContext *avctx)
         int nb_cpus = av_cpu_count();
         if ((avctx->debug & (FF_DEBUG_VIS_QP | FF_DEBUG_VIS_MB_TYPE)) || avctx->debug_mv)
             nb_cpus = 1;
-        av_log(avctx, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
         // use number of cores + 1 as thread count if there is more than one
         if (nb_cpus > 1)
             thread_count = avctx->thread_count = FFMIN(nb_cpus + 1, MAX_AUTO_THREADS);

libavfilter/pthread.c

@@ -150,7 +150,6 @@ static int thread_init(ThreadContext *c, int nb_threads)
 
     if (!nb_threads) {
         int nb_cpus = av_cpu_count();
-        av_log(c->graph, AV_LOG_DEBUG, "Detected %d logical cores.\n", nb_cpus);
         // use number of cores + 1 as thread count if there is more than one
         if (nb_cpus > 1)
             nb_threads = nb_cpus + 1;

libavutil/cpu.c

@@ -198,6 +198,8 @@ int av_parse_cpu_caps(unsigned *flags, const char *s)
 
 int av_cpu_count(void)
 {
+    static volatile int printed;
+
     int ret, nb_cpus = 1;
 #if HAVE_SCHED_GETAFFINITY && defined(CPU_COUNT)
     cpu_set_t cpuset;
@@ -226,6 +228,11 @@ int av_cpu_count(void)
     nb_cpus = sysconf(_SC_NPROCESSORS_ONLN);
 #endif
 
+    if (!printed) {
+        av_log(NULL, AV_LOG_DEBUG, "detected %d logical cores\n", nb_cpus);
+        printed = 1;
+    }
+
     return nb_cpus;
 }