ffplay: add specific constants for buffer fullness settings when using external clock

Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -67,6 +67,8 @@ const int program_birth_year = 2003;
 
 #define MAX_QUEUE_SIZE (15 * 1024 * 1024)
 #define MIN_FRAMES 5
+#define EXTERNAL_CLOCK_MIN_FRAMES 2
+#define EXTERNAL_CLOCK_MAX_FRAMES 10
 
 /* Minimum SDL audio buffer size, in samples. */
 #define SDL_AUDIO_MIN_BUFFER_SIZE 512
@@ -1301,11 +1303,11 @@ static double get_master_clock(VideoState *is)
 }
 
 static void check_external_clock_speed(VideoState *is) {
-   if (is->video_stream >= 0 && is->videoq.nb_packets <= MIN_FRAMES / 2 ||
-       is->audio_stream >= 0 && is->audioq.nb_packets <= MIN_FRAMES / 2) {
+   if (is->video_stream >= 0 && is->videoq.nb_packets <= EXTERNAL_CLOCK_MIN_FRAMES ||
+       is->audio_stream >= 0 && is->audioq.nb_packets <= EXTERNAL_CLOCK_MIN_FRAMES) {
        set_clock_speed(&is->extclk, FFMAX(EXTERNAL_CLOCK_SPEED_MIN, is->extclk.speed - EXTERNAL_CLOCK_SPEED_STEP));
-   } else if ((is->video_stream < 0 || is->videoq.nb_packets > MIN_FRAMES * 2) &&
-              (is->audio_stream < 0 || is->audioq.nb_packets > MIN_FRAMES * 2)) {
+   } else if ((is->video_stream < 0 || is->videoq.nb_packets > EXTERNAL_CLOCK_MAX_FRAMES) &&
+              (is->audio_stream < 0 || is->audioq.nb_packets > EXTERNAL_CLOCK_MAX_FRAMES)) {
        set_clock_speed(&is->extclk, FFMIN(EXTERNAL_CLOCK_SPEED_MAX, is->extclk.speed + EXTERNAL_CLOCK_SPEED_STEP));
    } else {
        double speed = is->extclk.speed;