[pvrusb2] Recording from radio
pakt223 at freemail.gr
Sun Jan 21 01:08:45 CST 2007
Στις Κυριακή 21 Ιανουάριος 2007 05:31, ο/η Rick Macdonald έγραψε:
> Anticipating getting the radio working, I've spent many hours now trying
> to figure out how to record from it.
> cat /dev/radioX > file.mpg
> works, but gives an MPEG file with no video. I want a wav file or
> something that I can convert to mp3.
mpeg2desc -a0 < /dev/radio0 > file.mp2
mpeg2desc is part of dvdauthor, or I can send you a standalone version
if you don 't want the dependencies of dvdauthor. There are many
utilities that can convert to mp3 (mp2 and mp3 are not that different).
(Mike: this should be a FAQ, or in the instructions please).
we may be able to do the video filtering inside the driiver (it seems to
even have some facilities for this) and maybe we can get it to be faster
than mpeg2desc since we can make some ugly assumptions
(and even change the muted video color to something more convenient
like black IIRC), but I 'm still undecided on whether that is a
"good thing" (TM).
The reason is that for pvrusb2 radio is just another input and you can
change that while streaming. So if you are playing with mplayer
and you change the input to radio behind its back it would be confused
to get a different stream, while now it isn 't.
>Should pvrusb2 act as much as possible like ivtv? pvrusb2 creates the
>radio0/video0 devices below, the rest are from ivtv due to my internal
Ivtv 's radioX does only ioctls but no streaming. (Trying to stream from
it returns -EPERM IIRC). This was also the behavior of pvrusb2 but then
after feedback from mauro (the v4l tree maintainer) it was decided that
it should be able to stream like all other devices.
We never did /dev/video24 (pcm) / /dev/video32 (yuv?) How to implement
these is still an open problem (actually only pcm is really interesting due
to USB bandwith constraints).
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