rtp发送高清视频，画面卡马赛克

请教下诸位，我在做ＲＴＰ发送
用ＶＬＣ播放，画面开始是正常，
播了约20分钟就开始有延迟，丢帧，马赛克
重启下ＶＬＣ，又恢复正常了，不知道是什么原因，
抓了部分ＶＬＣ的调试信息如下：

main warning: picture is too late to be displayed (missing 43 ms)
main debug: picture might be displayed late (missing 3 ms)
main warning: picture is too late to be displayed (missing 49 ms)
main warning: picture is too late to be displayed (missing 20 ms)
main warning: picture is too late to be displayed (missing 44 ms)
main debug: picture might be displayed late (missing 14 ms)
main warning: picture is too late to be displayed (missing 24 ms)
main warning: picture is too late to be displayed (missing 144 ms)
main warning: picture is too late to be displayed (missing 190 ms)
main warning: picture is too late to be displayed (missing 348 ms)
main warning: picture is too late to be displayed (missing 308 ms)
main warning: picture is too late to be displayed (missing 800 ms)
main warning: picture is too late to be displayed (missing 800 ms)
main warning: picture is too late to be displayed (missing 43 ms)
main debug: picture might be displayed late (missing 14 ms)
main warning: picture is too late to be displayed (missing 817 ms)
main warning: picture is too late to be displayed (missing 50 ms)
main warning: picture is too late to be displayed (missing 20 ms)
main warning: picture is too late to be displayed (missing 896 ms)