Enable libva message callbacks.

misc.h

@@ -51,7 +51,7 @@ extern void LogMessage(int trace, int level, const char *format, ...) __attribut
 #define Debug10(a...) LogMessage(10, 2, a)  // FFMPEG: info
 #define Debug11(a...) LogMessage(11, 2, a)  // FFMPEG: warning
 #define Debug12(a...) LogMessage(12, 2, a)  // FFMPEG: error
-#define Debug13(a...) LogMessage(13, 2, a)  // TBD
+#define Debug13(a...) LogMessage(13, 2, a)  // libva
 #define Debug14(a...) LogMessage(14, 2, a)  // TBD
 #define Debug15(a...) LogMessage(14, 2, a)  // TBD
 #define Debug16(a...) LogMessage(16, 2, a)  // TBD

video.c

@@ -1175,6 +1175,20 @@ static void VaapiInitSurfaceFlags(VaapiDecoder * decoder)
     }
 }
 
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57,107,100) // FFMPEG 3.4
+#if VA_CHECK_VERSION(1,0,0)
+static void VaapiInfoCallback(void *context, const char *msg)
+{
+    Debug13("libva: %s", msg);
+}
+
+static void VaapiErrorCallback(void *context, const char *msg)
+{
+    Debug13("libva/error: %s", msg);
+}
+#endif
+#endif
+
 ///
 /// Allocate new VA-API decoder.
 ///
@@ -1207,6 +1221,13 @@ static VaapiDecoder *VaapiNewHwDecoder(VideoStream * stream)
     decoder->VideoWidth = VideoWindowWidth;
     decoder->VideoHeight = VideoWindowHeight;
 
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(57,107,100) // FFMPEG 3.4
+#if VA_CHECK_VERSION(1,0,0)
+    vaSetInfoCallback(decoder->VaDisplay, VaapiInfoCallback, NULL);
+    vaSetErrorCallback(decoder->VaDisplay, VaapiErrorCallback, NULL);
+#endif
+#endif
+
     VaapiInitSurfaceFlags(decoder);
 
     decoder->Image->image_id = VA_INVALID_ID;