ffplay: decrease max audio callbacks per second

Too many audio callbacks per second can cause buffer underruns especially under
load. As now we take into accound the elapsed time after an audio callback when
determining current audio clock, it is not that important to use small buffer
sizes and frequent audio callbacks, so lets remove the comment.
Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -67,11 +67,10 @@ const int program_birth_year = 2003;
 #define MAX_QUEUE_SIZE (15 * 1024 * 1024)
 #define MIN_FRAMES 5
 
-/* Minimum SDL audio buffer size, in samples. Should be small to have precise
-   A/V sync as SDL does not have hardware buffer fullness info. */
+/* Minimum SDL audio buffer size, in samples. */
 #define SDL_AUDIO_MIN_BUFFER_SIZE 512
 /* Calculate actual buffer size keeping in mind not cause too frequent audio callbacks */
-#define SDL_AUDIO_MAX_CALLBACKS_PER_SEC 60
+#define SDL_AUDIO_MAX_CALLBACKS_PER_SEC 30
 
 /* no AV sync correction is done if below the minimum AV sync threshold */
 #define AV_SYNC_THRESHOLD_MIN 0.04