ffplay: ensure the decoder is flushed before exiting or looping

Also make sure that we only exit or restart the video if it is not paused and
if the picture queue is empty.

There is still room for improvement (filters may also buffer some frames), but
the patch fixes the most common use cases and ticket #2783 as well.
Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -177,6 +177,8 @@ typedef struct VideoState {
     int read_pause_return;
     AVFormatContext *ic;
     int realtime;
+    int audio_finished;
+    int video_finished;
 
     Clock audclk;
     Clock vidclk;
@@ -1673,6 +1675,9 @@ static int get_video_frame(VideoState *is, AVFrame *frame, AVPacket *pkt, int *s
     if(avcodec_decode_video2(is->video_st->codec, frame, &got_picture, pkt) < 0)
         return 0;
 
+    if (!got_picture && !pkt->data)
+        is->video_finished = *serial;
+
     if (got_picture) {
         int ret = 1;
         double dpts = NAN;
@@ -2170,6 +2175,8 @@ static int audio_decode_frame(VideoState *is)
                 pkt_temp->size -= len1;
                 if (pkt_temp->data && pkt_temp->size <= 0 || !pkt_temp->data && !got_frame)
                     pkt_temp->stream_index = -1;
+                if (!pkt_temp->data && !got_frame)
+                    is->audio_finished = is->audio_pkt_temp_serial;
 
                 if (!got_frame)
                     continue;
@@ -2899,6 +2906,16 @@ static int read_thread(void *arg)
             SDL_UnlockMutex(wait_mutex);
             continue;
         }
+        if (!is->paused &&
+            (!is->audio_st || is->audio_finished == is->audioq.serial) &&
+            (!is->video_st || (is->video_finished == is->videoq.serial && is->pictq_size == 0))) {
+            if (loop != 1 && (!loop || --loop)) {
+                stream_seek(is, start_time != AV_NOPTS_VALUE ? start_time : 0, 0, 0);
+            } else if (autoexit) {
+                ret = AVERROR_EOF;
+                goto fail;
+            }
+        }
         if (eof) {
             if (is->video_stream >= 0) {
                 av_init_packet(pkt);
@@ -2915,14 +2932,6 @@ static int read_thread(void *arg)
                 packet_queue_put(&is->audioq, pkt);
             }
             SDL_Delay(10);
-            if (is->audioq.size + is->videoq.size + is->subtitleq.size == 0) {
-                if (loop != 1 && (!loop || --loop)) {
-                    stream_seek(is, start_time != AV_NOPTS_VALUE ? start_time : 0, 0, 0);
-                } else if (autoexit) {
-                    ret = AVERROR_EOF;
-                    goto fail;
-                }
-            }
             eof=0;
             continue;
         }