Loggytronic Forum

VOMP => VOMP General / MVP => Topic started by: Lodda on August 03, 2008, 17:15:37

Title: maybe a stupid idea?
Post by: Lodda on August 03, 2008, 17:15:37
Hey Vompers , i am using vomp for a very long time and thank to all developers regarding that great job you have done.

I just now have a total different question and it would be great if you could give me an answer.

I have a videoCAM with composite and svideo connectors. What i want to do now is to connect this cam to a vompserver and bring the signal
through internet to a MVP.

What do you think, could this be possible.
If yes, how much bandwidth would i need for a good quality?
Thanks for a helping answer.
Lodda
Title: Re: maybe a stupid idea?
Post by: muellerph on August 03, 2008, 17:54:17
Regarding getting the cam signal to VDR:

For this you need a card like the Haupauge PVR 350. This encodes in live an analog signal into an MPEG stream and the PVRs are supported by VDR, at least mostly.
I have one, but never connected by digicam to it.
The PVR 350 and 500 are fine (maybe newer ones as well), but not the 150 or 250. They can only decode, but not encode.

The remaining (getting to the internet) is then another task - i.e. with regards to security.

____

Correction: I mixed that up. All PVRs can encode, but only the 350/500 can decode.
Title: Re: maybe a stupid idea?
Post by: Lodda on August 03, 2008, 19:17:01
Hey that sounds great. Thanks for your answer.
So the first step wont be a problem.
Does anybody knows the minimum bandwith?

Lodda
Title: Re: maybe a stupid idea?
Post by: Lutz on August 03, 2008, 22:49:31
Hi Lodda,
I think the PVR 150 or 250 will also do the job, they encode and do not decode I think, they are missing the hardware decoder, but they both transform a video stream to mpeg which can be used by vdr...
Lutz
Title: Re: maybe a stupid idea?
Post by: Chris on August 04, 2008, 00:51:49
As for bandwidth, you would have to find out how fast the upstream connection was out from the VDR box. I haven't used one of these encoder cards with VDR but I have just on its own - you should be able to set the bit rate for the encode process straight to the encoder card. It will then create a stream at that bit rate. VDR won't care or bother with what the bit rate is, it will just pass it along.

You will have to make sure the encode bit rate is just below what the internet links can support, because the MVP won't play nicely with a stream that can't run fast enough - the hardware and software isn't really designed for that use.

Now the bad news... Unless you have a really good broadband upstream rate you won't be able to get very good quality out of this - MPEG2 doesn't really work too well at the low bit rates of regular broadband upstream rates. E.g. Lets say an average TV station uses 2Mb/s.. But an average broadband upstream is what, up to 500Kb/s ? So the maximum quality you could get using these numbers would be a quarter of an average TV station. I suppose it depends what you want to use if for, maybe it would be ok...

As mullerph said you would need to allow access to the vomp port on your VDR box through your firewall - this is fairly bad for security as there is no authentication...... Also you would need the undocumented -s switch to vompclient, i.e. "vompclient -s my-vdr-server-ip" because the usual broadcast-for-server step certainly won't work over the internet :)

Good luck!
Title: Re: maybe a stupid idea?
Post by: Lodda on August 04, 2008, 06:33:42
@Lutz: I think i will give it a try.
@Chris: I want to let the signal go through a VPN . So i think i am safe. I can realize a line with 2Mbit/s or even up to 5Mbit/s in the Upload. Would that be OK for a nice picture? So the -s switches off the search for a VOMP-Server, right?

All the best
Lodda
Title: Re: maybe a stupid idea?
Post by: muellerph on August 04, 2008, 08:38:36
Quote from: Lutz on August 03, 2008, 22:49:31
Hi Lodda,
I think the PVR 150 or 250 will also do the job, they encode and do not decode I think, they are missing the hardware decoder, but they both transform a video stream to mpeg which can be used by vdr...
Lutz
Ups, sorry you are right. I mixed that up. So all PVRs should do the trick.
Title: Re: maybe a stupid idea?
Post by: muellerph on August 04, 2008, 08:47:29
Quote from: Lodda on August 04, 2008, 06:33:42
@Lutz: I think i will give it a try.
@Chris: I want to let the signal go through a VPN . So i think i am safe. I can realize a line with 2Mbit/s or even up to 5Mbit/s in the Upload. Would that be OK for a nice picture? So the -s switches off the search for a VOMP-Server, right?
DVB-T doesn't have in average much more than 2Mbit/s per channel. So you could test this one and if unsatisfying use the 5Mbit/s (which is even close to average DVB-S).
Other possibility:
You may also check using a normal WebCam. Won't have normally 30pictures/s, but in case quality is not the important issue may be a better solution. See the VDR Wiki for possible solutions.
Title: Re: maybe a stupid idea?
Post by: Lodda on August 04, 2008, 10:32:18
hey muellerph,
for the input i have a DV-Cam. And that is what i need, because the quality is one of the most important thing.
I am really happy that this seems to be such easy. I am now trying to buy a PVR as fast as possible.
Lodda :-)
Title: Re: maybe a stupid idea?
Post by: Lodda on August 07, 2008, 23:23:26
@Chris: Hey Chris, how exactly do i use this -s switch?
I have a working dongle development environment here. Where shall i tell the MVP the ip of the server?
Best :-)
Lothar
Title: Re: maybe a stupid idea?
Post by: Chris on August 08, 2008, 00:16:09
The -s switch is an argument to vompclient, so you would say:

vompclient -s 10.0.0.1

for instance. Obviously the stock dongle doesn't have this, so for a one-off you can telnet into the mvp, kill vompclient and restart it by hand with the switch. Or for a more permanent you would need to make yourself a custom dongle with the -s switch in the boot file. In your dev environment, see [vomp]/dongle/tofs/etc/rcS.
Title: Re: maybe a stupid idea?
Post by: Sir George on August 08, 2008, 00:17:15
Hi Lodda,
I'll give it a try :)

Look into vomp/dongle/tofs/etc/rcS and edit the last line into "/vompclient -s 10.0.0.3" (where 10.0.0.3 is your VDR server's IP)
Now do a ./build in the dongle directory, and there's your new vomp-dongle.

For testing you could also telnet to your mvp, "killall vompclient" and start "/vompclient -s IP" manually

@Chris: This must have been telepathy ;D
Title: Re: maybe a stupid idea?
Post by: Lodda on August 08, 2008, 07:16:25
Great! Thanks for your help.
Does that -s switch works with vomp4windows also?
Lodda :-)
Title: Re: maybe a stupid idea?
Post by: Chris on August 09, 2008, 16:19:02
No the -s switch won't work on Windows. You would need to ask Marten if he could implement it.
Title: Re: maybe a stupid idea?
Post by: Lodda on August 26, 2008, 16:18:43
hi to ALL,
i now have the PVR350 running in an easyvdr environment. Also a cam is connected and i can see the signal on my vdr. I've tried the streamdev plugin and over the network with VLC the stream comes perfectly (VLC-networkstream URL: http://[ip-adress]:3000/1
unfortunatly the vompserver does still give me a dark picture. It seems to me that this has something to do with the TS or PES Stream.
But i guess it's better to ask you what to do ??

All the best from Lodda :-)
Title: Re: maybe a stupid idea?
Post by: muellerph on August 27, 2008, 11:46:35
Nobody is answering yet, so I will give it a try:
- The black screen is on MVP or Windowsclient or on both?
- In case MVP, what does the log spit out when you enable logoutput?
- What are the settings for the PVR card? Does it give e.g. PAL in normal resolution or something different? Maybe if it is not the same format then the internal decoders get issues...
Title: Re: maybe a stupid idea?
Post by: Chris on September 10, 2008, 17:04:43
The log from the MVP would be most interesting for clues. One thought I have had is that if there is no audio stream then I don't think the vomp code will play it. I would have to look into how to fix that for you.