Sending DV to camcorder over firewire gives dropouts

Dieter freebsd at sopwith.solgatos.com
Sun Nov 6 19:09:32 PST 2005


> > Wild Guess Theory #1:
> > 
> >     fwcontrol -S reports:
> > 
> > 	3948 frames, 131.50 secs, 30.02 frames/sec
> > 	784 frames, 25.92 secs, 30.24 frames/sec
> > 	3597 frames, 119.78 secs, 30.03 frames/sec
> > 
> >     Shouldn't this be 29.97 fps ?
> > 
> I like that theory:
> 
> I found in ffmpeg's man page the following option:
>        -r fps
>            set frame rate (default = 25)
> 
> Dude! Did you use the "-r" option?

No, didn't need to, ffmpeg figured out to use 29.97 fps
all by itself, for both input and output.

Even if there is something wrong with the output of ffmpeg,
it would not explain why I get the exact same problem with:

	[ push "play" button on camcorder ]
	fwcontrol -R filename.dv
	[ push "stop" button on camcorder ]
	fwcontrol -S filename.dv

since ffmpeg is not involved in this case.

It might be that the incorrect fps numbers reported are just
an artifact of clock resolution and the relatively short times
involved and packetization/buffering?


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