Мозаика ffmpeg из потоков wowza

Я пытаюсь сделать мозаику из 16 живых потоков wowza с помощью ffmpeg. Я включил поддержку nvenc в ffmpeg и сделал мозаику потоковой передачи. Но видео воспроизводится с небольшими паузами. Видео не воспроизводятся синхронно. Вот мой сценарий:

 #!/bin/bash
/home/sysadmin/Downloads/ffmpeg-3.2.4/ffmpeg 
-i rtsp://10.10.0.46:1935/live/stream1.stream 
-i rtsp://10.10.0.46:1935/live/stream2.stream 
-i rtsp://10.10.0.46:1935/live/stream3.stream 
-i rtsp://10.10.0.46:1935/live/stream4.stream 
-i rtsp://10.10.0.46:1935/live/stream5.stream 
-i rtsp://10.10.0.46:1935/live/stream6.stream 
-i rtsp://10.10.0.46:1935/live/stream7.stream 
-i rtsp://10.10.0.46:1935/live/stream8.stream 
-i rtsp://10.10.0.46:1935/live/stream9.stream 
-i rtsp://10.10.0.46:1935/live/stream10.stream 
-i rtsp://10.10.0.46:1935/live/stream11.stream 
-i rtsp://10.10.0.46:1935/live/stream12.stream 
-i rtsp://10.10.0.46:1935/live/stream13.stream 
-i rtsp://10.10.0.46:1935/live/stream14.stream 
-i rtsp://10.10.0.46:1935/live/stream15.stream 
-i rtsp://10.10.0.46:1935/live/stream16.stream 
-filter_complex "nullsrc=size=1280x720 [base];[0:v] setpts=PTS-STARTPTS, scale=320x180 [vid1]; [1:v] setpts=PTS-STARTPTS, scale=320x180 [vid2];[2:v] setpts=PTS-STARTPTS, scale=320x180 [vid3]; [3:v] setpts=PTS-STARTPTS, scale=320x180 [vid4]; [4:v] setpts=PTS-STARTPTS, scale=320x180 [vid5]; [5:v] setpts=PTS-STARTPTS, scale=320x180 [vid6]; [6:v] setpts=PTS-STARTPTS, scale=320x180 [vid7];[7:v] setpts=PTS-STARTPTS, scale=320x180 [vid8]; [8:v] setpts=PTS-STARTPTS, scale=320x180 [vid9]; [9:v] setpts=PTS-STARTPTS, scale=320x180 [vid10]; [10:v] setpts=PTS-STARTPTS, scale=320x180 [vid11]; [11:v] setpts=PTS-STARTPTS, scale=320x180 [vid12]; [12:v] setpts=PTS-STARTPTS, scale=320x180 [vid13]; [13:v] setpts=PTS-STARTPTS, scale=320x180 [vid14]; [14:v] setpts=PTS-STARTPTS, scale=320x180 [vid15]; [15:v] setpts=PTS-STARTPTS, scale=320x180 [vid16]; [base][vid1] overlay=shortest=1 [tmp1]; [tmp1][vid2] overlay=shortest=1:x=320 [tmp2]; [tmp2][vid3] overlay=shortest=1:x=640 [tmp3]; [tmp3][vid4] overlay=shortest=1:x=960 [tmp4]; [tmp4][vid5] overlay=shortest=1:y=180 [tmp5]; [tmp5][vid6] overlay=shortest=1:x=320:y=180 [tmp6]; [tmp6][vid7] overlay=shortest=1:x=640:y=180 [tmp7]; [tmp7][vid8] overlay=shortest=1:x=960:y=180 [tmp8]; [tmp8][vid9] overlay=shortest=1:y=360 [tmp9]; [tmp9][vid10] overlay=shortest=1:x=320:y=360 [tmp10]; [tmp10][vid11] overlay=shortest=1:x=640:y=360 [tmp11]; [tmp11][vid12] overlay=shortest=1:x=960:y=360 [tmp12]; [tmp12][vid13] overlay=shortest=1:y=540 [tmp13]; [tmp13][vid14] overlay=shortest=1:x=320:y=540 [tmp14]; [tmp14][vid15] overlay=shortest=1:x=640:y=540 [tmp15]; [tmp15][vid16] overlay=shortest=1:x=960:y=540" -strict experimental -c:v h264_nvenc -f mpegts udp://225.50.50.111:9001?pkt_size=1316