fftools/ffmpeg: use a mutex for enc_stats_write()

It may be called concurrently from different threads to write into the
same file.

1 files changed, 3 insertions, 0 deletions

diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 03dbb528c0..33a29b316f 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -480,6 +480,9 @@ typedef struct EncStats {
     int              nb_components;
 
     AVIOContext        *io;
+
+    pthread_mutex_t     lock;
+    int                 lock_initialized;
 } EncStats;
 
 extern const char *const forced_keyframes_const_names[];