ffmpeg多路流合并

ffmpeg -rtsp_transport tcp -i "rtsp://hik-isc.geili.cn:554/openUrl/J5ONne9" -rtsp_transport tcp -i "rtsp://hik-isc.geili.cn:554/openUrl/J5ONneb" -rtsp_transport tcp -i "rtsp://hik-isc.geili.cn:554/openUrl/J5ONnea" -rtsp_transport tcp -i "rtsp://hik-isc.geili.cn:554/openUrl/J5ONne8" -c:v libx264 -filter_complex "nullsrc=size=1440x810 [base];[0:v] setpts=PTS-STARTPTS, scale=720x405 [upperleft];[1:v] setpts=PTS-STARTPTS, scale=720x405 [upperright];[2:v] setpts=PTS-STARTPTS, scale=720x405 [lowerleft];[3:v] setpts=PTS-STARTPTS,scale=720x405 [lowerright];[base][upperleft] overlay=shortest=1[tmp1];[tmp1][upperright]overlay=shortest=1:x=720 [tmp2];[tmp2][lowerleft] overlay=shortest=1:y=405 [tmp3];[tmp3][lowerright]overlay=shortest=1:x=720:y=405" -f flv -r 25 -s 1440x810 -an rtmp://localhost/live/livestream