Code:
rtmpdump -r "rtmp://sdwfchwqitj2v.cloudfront.net/cfx/st/" -a "cfx/st/" -f "WIN 12,0,0,77" -W "http://d27s92d8z1yatv.cloudfront.net/lib/jwplayer/jwplayer.flash.swf" -p "http://video.pbs.org/video/2365189896/" -y "mp4:videos/pbs-arts/11b79844-4f66-4b2f-baa3-5acf17076879/119503/hd-mezzanine-16x9/jazr0000_4_mezz16x9-16x9-mp4-2500k.mp4" -o "output.flv"
i have change from 400k to 2500k
2500k is the best quality and resolution