/* maximum audio speed change to get correct sync */
#define SAMPLE_CORRECTION_PERCENT_MAX 10
+/* external clock speed adjustment constants for realtime sources based on buffer fullness */
+#define EXTERNAL_CLOCK_SPEED_MIN 0.900
+#define EXTERNAL_CLOCK_SPEED_MAX 1.010
+#define EXTERNAL_CLOCK_SPEED_STEP 0.001
+
/* we use about AUDIO_DIFF_AVG_NB A-V differences to make the average */
#define AUDIO_DIFF_AVG_NB 20
int64_t seek_rel;
int read_pause_return;
AVFormatContext *ic;
+ int realtime;
int audio_stream;
double external_clock; ///< external clock base
double external_clock_drift; ///< external clock base - time (av_gettime) at which we updated external_clock
int64_t external_clock_time; ///< last reference time
+ double external_clock_speed; ///< speed of the external clock
double audio_clock;
double audio_diff_cum; /* used for AV difference average computation */
if (is->paused) {
return is->external_clock;
} else {
- return is->external_clock_drift + av_gettime() / 1000000.0;
+ double time = av_gettime() / 1000000.0;
+ return is->external_clock_drift + time - (time - is->external_clock_time / 1000000.0) * (1.0 - is->external_clock_speed);
}
}
}
}
+static void update_external_clock_speed(VideoState *is, double speed) {
+ update_external_clock_pts(is, get_external_clock(is));
+ is->external_clock_speed = speed;
+}
+
+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) {
+ update_external_clock_speed(is, FFMAX(EXTERNAL_CLOCK_SPEED_MIN, is->external_clock_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)) {
+ update_external_clock_speed(is, FFMIN(EXTERNAL_CLOCK_SPEED_MAX, is->external_clock_speed + EXTERNAL_CLOCK_SPEED_STEP));
+ } else {
+ double speed = is->external_clock_speed;
+ if (speed != 1.0)
+ update_external_clock_speed(is, speed + EXTERNAL_CLOCK_SPEED_STEP * (1.0 - speed) / fabs(1.0 - speed));
+ }
+}
+
/* seek in the stream */
static void stream_seek(VideoState *is, int64_t pos, int64_t rel, int seek_by_bytes)
{
SubPicture *sp, *sp2;
+ if (!is->paused && get_master_sync_type(is) == AV_SYNC_EXTERNAL_CLOCK && is->realtime)
+ check_external_clock_speed(is);
+
if (is->video_st) {
if (is->force_refresh)
pictq_prev_picture(is);
}
}
+ is->realtime = is_realtime(ic);
+
for (i = 0; i < ic->nb_streams; i++)
ic->streams[i]->discard = AVDISCARD_ALL;
if (!video_disable)
goto fail;
}
- if (infinite_buffer < 0 && is_realtime(ic))
+ if (infinite_buffer < 0 && is->realtime)
infinite_buffer = 1;
for (;;) {
is->continue_read_thread = SDL_CreateCond();
update_external_clock_pts(is, 0.0);
+ update_external_clock_speed(is, 1.0);
is->audio_current_pts_drift = -av_gettime() / 1000000.0;
is->video_current_pts_drift = is->audio_current_pts_drift;
is->av_sync_type = av_sync_type;