linux1394-devel

Receiving Video from other Computer

[<fra...@ya...>]

Since few days I started to work on isochronous
transfers. The main
difficultie is that I don't (and I can't) have a
camrecorder to
generate an isochronous flow. Moreover, the IEEE 1394
linux subsystem is not
able to generate one too. 

But I have a FireWire iMac and a PC-windoz, that are
able to
output isochronous packets IF they thought there is a
TapeRecorderPlayer connected to the bus.

So I have tryed to transform my PC-linux in an
TapeRecorderPlayer and
today I have succeded, by re-writing the ohci_csr_rom
located in the
ohci1394.h file.

Now, the Imac think that my Pc-linux is a TapeRecorder
and send it lots
of fcp commands and isochronous packets that I can
grab with dvgrab
(but can not see with libdv) or I can directly see the
movie with
xdv. But since I don't now exactly how an IEEE 1394
TapeRecorder has
to react, I just ask if someone is interrested by such
work or has any
experience with the AVC protocol for
TapeRecorderPlayer.

I still have a problem concerning video decoding with
xdv.
I have attach a sample from the output gave by xdv
(does anyone see the dog ?).

My goal is to build a TapeRecorder emulator on the top
of the IEEE
1394 linux subsystem and one day (when isochronous
output will work) a
tape player.

---

Franck Bonin


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Re: Receiving Video from other Computer

[Andreas M. <ami@@ivistar.de>]

Hi,

On Thu, May 11, 2000 at 04:11:07PM +0200, Franck Bonin wrote:
> So I have tryed to transform my PC-linux in an
> TapeRecorderPlayer and
> today I have succeded, by re-writing the ohci_csr_rom
> located in the ohci1394.h file.

That is great. Right now I use the Linux 1394 subsystem mainly for controlling
a digital VCR. A virtual VCR on another Linux host would provide the perfect
debugging tool for testing all those optional features that real VCRs do not
implement yet.

If you have some more specific questions, feel free to ask. You can also send
me your source if you like.

I would also like to see this thing run on an unmodofied Linux kernel. We
would need an interface for changing the CSR ROM at run time, oder maybe the
driver module should read the CSR rom from a file. The filename could be
specified at module loading time as an optional parameter. What do the driver
maintainers think of this idea?

   bye...
         Andreas Micklei

Re: Receiving Video from other Computer

[Andreas B. <and...@mu...>]

On Thu, May 11, 2000 at 04:34:48PM +0200, lin...@li... wrote:
> Hi,
> 
> On Thu, May 11, 2000 at 04:11:07PM +0200, Franck Bonin wrote:
> > So I have tryed to transform my PC-linux in an
> > TapeRecorderPlayer and
> > today I have succeded, by re-writing the ohci_csr_rom
> > located in the ohci1394.h file.
[...]
> I would also like to see this thing run on an unmodofied Linux kernel. We
> would need an interface for changing the CSR ROM at run time, oder maybe the
> driver module should read the CSR rom from a file. The filename could be
> specified at module loading time as an optional parameter. What do the driver
> maintainers think of this idea?

Reading from a file is not a good idea (reading a config file from
kernel is not good and requires the kernel to know the file path).
Dynamically creating the CSR ROM is a good idea however.

We'd need some functions to create the ROM from an arbitrary number of
info blocks.  The header and bus info block is simple, the following
root directory should be created on the fly from block info.  The 1394
standard I have here doesn't give really detailed information on that,
instead it references ISO/IEC 13213: 1994.

Anyone wants to write support for that?  Shouldn't be too hard if you
know the exact implementation of CSR ROMs.

-- 
 Andreas E. Bombe <and...@mu...>    DSA key 0x04880A44
http://home.pages.de/~andreas.bombe/    http://linux1394.sourceforge.net/

Re: Receiving Video from other Computer

[<br...@pr...>]

> I still have a problem concerning video decoding with
> xdv.
> I have attach a sample from the output gave by xdv
> (does anyone see the dog ?).

That looks exactly like an NTSC DV decoder fed with PAL DV material.
The 'DVGate Still' windoze app that came with my Vaio did the same
thing. Unfortunately it doesn't autodetect the video standard - it's
hard-coded with a registry setting!!! I'd hope that xdv can do
better than that (eventually).

I heard that libdv is currently NTSC only - maybe that explains it?

Otherwise nice work :)

Brian.



--
--
-----------------------------------
Brian Murray      Proximity Pty Ltd
http://www.proximity.com.au/~brian/
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