[hasomaso]

you must create extra a playpath -y line

-y "mp4:u/nfl/nfl/coachtapes/2014/56214_all_1600"

try that

rtmpdump -r "rtmp://neulionms.fcod.llnwd.net/a5306/e1/" -y "mp4:u/nfl/nfl/coachtapes/2014/56214_all_1600" -o "output.flv"

RTMPDump v2.4 GIT-2014-07-07 (Compiled by KSV)
(c) 2010 Andrej Stepanchuk, Howard Chu, The Flvstreamer Team; license: GPL
WARNING: You haven't specified an output file (-o filename), using stdout
Connecting ...
INFO: Connected...
Starting download at: 0.000 kB
INFO: Metadata:
INFO:   duration                4772.42
INFO:   moovPosition            32.00
INFO:   width                   960.00
INFO:   height                  540.00
INFO:   videocodecid            avc1
INFO:   avcprofile              77.00
INFO:   avclevel                31.00
INFO:   videoframerate          29.97
INFO: trackinfo:
INFO:   length                  4772423.00
INFO:   timescale               1000.00
INFO:   language                und
INFO: sampledescription:
INFO:   sampletype              avc1
INFO:   length                  429518070.00
INFO:   timescale               90000.00
INFO:   language                und
INFO: sampledescription:
15847.985 kB / 87.42 sec (1.8%)