To capture video from a firewire device use:

dvgrab -frames 0 -size 0 -format raw -noavc -showstatus -csize 1000 tape
dvgrab -frames 0 -size 0 -format dv2 -noavc -showstatus -csize 1000 tape
dvgrab -size 0 -format

best options:

dvgrab -autosplit -frames 0 -size 0 -format raw -noavc -showstatus -timestamp tape

where

-frames number    max number of frames per split
                         0 = unlimited [default 0]
-size number             max file size, 0 = unlimited [default 1000]
-csize number     split file when collections of files are about to exceed
                         number MiB, 0 = unlimited [default 0]
-format type      save as one of the following file types [default raw]
             raw         raw DV file with a .dv extension
             dif         raw DV file with a .dif extension
             dv1         'Type 1' DV AVI file
             dv2, avi    'Type 2' DV AVI file
             qt, mov     QuickTime DV movie
             mpeg2, hdv  MPEG-2 transport stream (HDV)
             jpeg, jpg   sequence of JPEG files (DV only)
-noavc                   disable use of AV/C VTR control
-srt                     generate .srt subtitle files containing the recording date and time in SRT format.
-t, -timestamp           Put information on date and time of recording into file name.
-a, -autosplit[=num]     Try to detect whenever a new recording starts, and store it into a separate file. This can be combined with the -frames and -size options, and a  split  occurs  whenever  a  specified  event arises.  Autosplit is off by default.

tape is the filename

Format types:


raw
Input #0, dv, from 'test-raw001.dv':                                                                                                                                                                                 
  Duration: 00:00:29.12, start: 0.000000, bitrate: 28800 kb/s
    Stream #0.0: Video: dvvideo, yuv420p, 720x576, 28800 kb/s, PAR 16:15 DAR 4:3, 25 tbr, 25 tbn, 25 tbc
    Stream #0.1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s

dv1
Input #0, avi, from 'test-dv1001.avi':                                                                                                                                                                               
  Duration: 00:00:29.08, start: 0.000000, bitrate: 30336 kb/s
    Stream #0.0: Video: dvvideo, yuv420p, 720x576, 28800 kb/s, PAR 16:15 DAR 4:3, 25 tbr, 25 tbn, 25 tbc
    Stream #0.1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s

dv2
Input #0, avi, from 'test-dv2001.avi':
  Duration: 00:00:27.64, start: 0.000000, bitrate: 30345 kb/s
    Stream #0.0: Video: dvvideo, yuv420p, 720x576 [PAR 16:15 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
    Stream #0.1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s