ffplay: only output null packet once on EOF

The generic decoder properly flushes the codecs with one null packet as well.
Signed-off-by: Marton Balint <cus@passwd.hu>

ffplay.c

@@ -3110,27 +3110,25 @@ static int read_thread(void *arg)
                 goto fail;
             }
         }
-        if (eof) {
-            if (is->video_stream >= 0)
-                packet_queue_put_nullpacket(&is->videoq, is->video_stream);
-            if (is->audio_stream >= 0)
-                packet_queue_put_nullpacket(&is->audioq, is->audio_stream);
-            if (is->subtitle_stream >= 0)
-                packet_queue_put_nullpacket(&is->subtitleq, is->subtitle_stream);
-            SDL_Delay(10);
-            eof=0;
-            continue;
-        }
         ret = av_read_frame(ic, pkt);
         if (ret < 0) {
-            if (ret == AVERROR_EOF || avio_feof(ic->pb))
+            if ((ret == AVERROR_EOF || avio_feof(ic->pb)) && !eof) {
+                if (is->video_stream >= 0)
+                    packet_queue_put_nullpacket(&is->videoq, is->video_stream);
+                if (is->audio_stream >= 0)
+                    packet_queue_put_nullpacket(&is->audioq, is->audio_stream);
+                if (is->subtitle_stream >= 0)
+                    packet_queue_put_nullpacket(&is->subtitleq, is->subtitle_stream);
                 eof = 1;
+            }
             if (ic->pb && ic->pb->error)
                 break;
             SDL_LockMutex(wait_mutex);
             SDL_CondWaitTimeout(is->continue_read_thread, wait_mutex, 10);
             SDL_UnlockMutex(wait_mutex);
             continue;
+        } else {
+            eof = 0;
         }
         /* check if packet is in play range specified by user, then queue, otherwise discard */
         stream_start_time = ic->streams[pkt->stream_index]->start_time;