[pvrusb2] Functionality Questions

[Mike Isely]

On Thu, 29 Jun 2006, Mathew Brown wrote:

>  Hi,

>  I've been thinking of purchasing a Hauppage for quite some time now, 
> but since I just got a laptop, I was looking for something that can run 
> on both my desktop and my laptop machines, depending on which one I'm 
> using.  So I came across the WinTV-PVR-USB2 and in search for Linux 
> drivers for it, I came across your site.  I still haven't purchased it 
> and was wondering if you can help make my decision by answering the 
> following questions:

>  a) how would you compare the driver for the WinTV-PVR-USB2 with that 
> for something like the Hauppage PVR350 in terms of features / maturity?

The WinTV-PVR-USB2 device is roughly comparable to a PVR-250 or a PVR-150, 
with the difference being of course that the WinTV-PVR-USB2 is USB hosted 
while the others are PCI.  The PVR-350 adds a video output with hardware 
mpeg decoder compared to the PVR-250 and PVR-150.

In terms of maturity, the ivtv driver is far larger and more mature.  It's 
been around a lot longer and has to support a larger variety of devices 
(the PVR-350 in particular involves additional effort on the driver's 
behalf).  I've only been maintaining the pvrusb2 driver for about the past 
year.  I was not the original author; I took it over when the original 
author disappeared.  The pvrusb2 driver is quite stable.  There are still 
missing features, but there's certainly enough to make a good PVR system 
with it when combined with, say, MythTV.

There is some complexity in setting up the driver, being that it's 
out-of-tree, requires a number of support modules, and you have to extract 
and install a bunch of firmware.  The same is true of the ivtv driver. 
However the situation is improving with time.  In both cases, the needed 
support modules are all in the kernel now, and in the pvrusb2 case it 
appears that the driver itself will be in the kernel starting with 2.6.18. 
The ivtv driver will probably appear in the kernel in the 2.6.19 
timeframe.


>  b) What exactly is the difference between the "WINTV-USB2" 
> (http://www.hauppauge.com/pages/products/data_usb2.html) and the 
> WINTV-PVR-USB2 
> (http://www.hauppauge.com/pages/products/data_pvrusb2.html)?  I get the 
> feeling that they are both basically the same with the USB2 being 
> slightly less expensive.

The biggest similarity is the name; beyond that the two devices are 
considerably different.  The "non-PVR" device does not include a hardware 
mpeg encoder.  It is essentially a dumb frame buffer capture device 
conencted by USB.  Its internal architecture is considerably different 
(beyond just not having the mpeg encoder).

If you are just interested in watching TV, then the non-PVR device might 
be the better choice - no need for an mpeg decoder anywhere in the path. 
On the other hand if you want to set up a PVR type of arrangement where 
you actually want to store the video somewhere, then you need to compress 
the video somewhere.  In that case you're far better off with a device 
that can do mpeg encoding in hardware, i.e. use the "PVR" version of the 
device.


>  c) Is it fully integrated with V4L so I can do thing such as set a 
> program to record at a given time, etc.

The pvrusb2 driver is V4L compatible to the extent that any mpeg2-native 
device can be V4L compatible.  This means that any V4L app which can 
decode mpeg2 data (e.g. MythTV, xawtv 4.x) should be able to work with 
this device.  I suggest you look at the usage page on the web site where 
you'll see specific information about various apps that can work.

Questions regarding setting a recording time etc are not a driver issue. 
That is a feature of the app, like MythTV.

   -Mike

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