I have searched and searched but cannot find an answer to the following questions. Any assistance would be greatly appreciated!
Microsoft says “In general, software filters use filter-centric
processing and hardware filters use pin-centric processing. <…> There
are rare cases in which these roles may be reversed.”
Q1) Please provide an example of the case, where a hardware filter uses filter-centric
processing.
Q2) What reason(s) may be behind that?
A Video Capture adapter has many examples of a hardware filter, TV Tuner, FM Radio, TVAudio, IF Demodulators and Video Decoders. The DDK src\wdm\videocap\atiwdm\ Tuner\1226 has a sample of
a TV Tuner.
The “PINS” if you will are still really hardware signals (RF) that needs to be converted. So the PINS
for these filters are still found physically on the adapter between the Tuner, Noise filters, IF demodulators
and a Video decoder. Now the output is suitable to become a PIN centric filter providing video data.
The TVTuner would have properties to set frequency, check for tuning / signal status and demodulation
modes.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
I have searched and searched but cannot find an answer to the following questions. Any assistance would be greatly appreciated!
Microsoft says “In general, software filters use filter-centric
processing and hardware filters use pin-centric processing. <…> There
are rare cases in which these roles may be reversed.”
Q1) Please provide an example of the case, where a hardware filter uses filter-centric
processing.
Q2) What reason(s) may be behind that?
Thanks Phil,
Unfortunately, I don’t have access to the DDK, and I was really interested in an example of a filter-centric hardware filter, as opposed to a pin-centric hardware filter. Microsoft calls this case a *rare* exception. Why would this case be so rare?
Thanks,
Tim
----- Original Message -----
From: Phil Sikora
Newsgroups: ntdev
To: Windows System Software Devs Interest List
Sent: Friday, May 20, 2005 9:08 AM
Subject: Re:[ntdev] Hardware Filter & Filter-centric
A Video Capture adapter has many examples of a hardware filter, TV Tuner, FM Radio, TVAudio, IF Demodulators and Video Decoders. The DDK src\wdm\videocap\atiwdm\ Tuner\1226 has a sample of
a TV Tuner.
The “PINS” if you will are still really hardware signals (RF) that needs to be converted. So the PINS
for these filters are still found physically on the adapter between the Tuner, Noise filters, IF demodulators
and a Video decoder. Now the output is suitable to become a PIN centric filter providing video data.
The TVTuner would have properties to set frequency, check for tuning / signal status and demodulation
modes.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
I have searched and searched but cannot find an answer to the following questions. Any assistance would be greatly appreciated!
Microsoft says “In general, software filters use filter-centric
processing and hardware filters use pin-centric processing. <…> There
are rare cases in which these roles may be reversed.”
Q1) Please provide an example of the case, where a hardware filter uses filter-centric
processing.
Q2) What reason(s) may be behind that? —
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com
Hi Tim:
I think the reference to “rare” is in the DDK docs.
"In general, software filters use filter-centric processing and hardware filters use pin-centric processing. For instance, hardware that transforms or renders data could route data on a pin-centric filter. There are rare cases in which these roles may be reversed. "
Hence my TV Tuner example.
Or your reference to rare may mean that a these filter-centric (TV Tuner) hardware filter do not
use a entry for PFNKSFILTERPROCESS Process, to perform the processing part of the filter.
Which off hand I would agree is rare. Mainly what is required from a filter-centric filter using
hardware is set/get properties and modes not a processing component.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
Thanks Phil,
Unfortunately, I don’t have access to the DDK, and I was really interested in an example of a filter-centric hardware filter, as opposed to a pin-centric hardware filter. Microsoft calls this case a rare exception. Why would this case be so rare?
Thanks,
Tim
----- Original Message -----
From: Phil Sikora
Newsgroups: ntdev
To: Windows System Software Devs Interest List
Sent: Friday, May 20, 2005 9:08 AM
Subject: Re:[ntdev] Hardware Filter & Filter-centric
A Video Capture adapter has many examples of a hardware filter, TV Tuner, FM Radio, TVAudio, IF Demodulators and Video Decoders. The DDK src\wdm\videocap\atiwdm\ Tuner\1226 has a sample of
a TV Tuner.
The “PINS” if you will are still really hardware signals (RF) that needs to be converted. So the PINS
for these filters are still found physically on the adapter between the Tuner, Noise filters, IF demodulators
and a Video decoder. Now the output is suitable to become a PIN centric filter providing video data.
The TVTuner would have properties to set frequency, check for tuning / signal status and demodulation
modes.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
I have searched and searched but cannot find an answer to the following questions. Any assistance would be greatly appreciated!
Microsoft says “In general, software filters use filter-centric
processing and hardware filters use pin-centric processing. <…> There
are rare cases in which these roles may be reversed.”
Q1) Please provide an example of the case, where a hardware filter uses filter-centric
processing.
Q2) What reason(s) may be behind that? —
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com
From what I understand about filter centric AVStream minidrivers (all of my drivers are/were
pin-centric) is that they support only one data flow and therefore can be used only for
single-stream cases.
In todays world most of A/V hardware support multiple streams of different formats. As the result
what you have is a streaming pin per hardwares supported data flow. Thus the driver becomes
pin-centric.
I can imagine some transcoder hardware (say, DV to MPEG2 for example). For that piece of hardware
filter-centric driver would be a natural choice. However mostly filter-centric things are used for
software encoder/decoder drivers such as Teletext or Closed Captions decoders.
– Max.
From: xxxxx@lists.osr.com [mailto:xxxxx@lists.osr.com] On Behalf Of Phil
Sikora
Sent: Friday, May 20, 2005 8:54 AM
To: Windows System Software Devs Interest List
Subject: Re:[ntdev] Re:Hardware Filter & Filter-centric
Hi Tim:
I think the reference to “rare” is in the DDK docs.
"In general, software filters use filter-centric processing and hardware filters use pin-centric
processing. For instance, hardware that transforms or renders data could route data on a
pin-centric filter. There are rare cases in which these roles may be reversed. "
Hence my TV Tuner example.
Or your reference to rare may mean that a these filter-centric (TV Tuner) hardware filter do not
use a entry for PFNKSFILTERPROCESS Process, to perform the processing part of the filter.
Which off hand I would agree is rare. Mainly what is required from a filter-centric filter using
hardware is set/get properties and modes not a processing component.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
Thanks Phil,
Unfortunately, I don’t have access to the DDK, and I was really interested in an example of a
filter-centric hardware filter, as opposed to a pin-centric hardware filter. Microsoft calls
this case a rare exception. Why would this case be so rare?
Thanks,
Tim
----- Original Message -----
From: Phil Sikora
Newsgroups: ntdev
To: Windows System Software Devs Interest List
Sent: Friday, May 20, 2005 9:08 AM
Subject: Re:[ntdev] Hardware Filter & Filter-centric
A Video Capture adapter has many examples of a hardware filter, TV Tuner, FM Radio, TVAudio, IF
Demodulators and Video Decoders. The DDK src\wdm\videocap\atiwdm\ Tuner\1226 has a sample of
a TV Tuner.
The “PINS” if you will are still really hardware signals (RF) that needs to be converted. So the
PINS
for these filters are still found physically on the adapter between the Tuner, Noise filters, IF
demodulators
and a Video decoder. Now the output is suitable to become a PIN centric filter providing video
data.
The TVTuner would have properties to set frequency, check for tuning / signal status and
demodulation
modes.
Phil
“Tim McDaniel” wrote in message news:xxxxx@ntdev…
I have searched and searched but cannot find an answer to the following questions. Any assistance
would be greatly appreciated!
Microsoft says “In general, software filters use filter-centric
processing and hardware filters use pin-centric processing. <…> There
are rare cases in which these roles may be reversed.”
Q1) Please provide an example of the case, where a hardware filter uses filter-centric
processing.
Q2) What reason(s) may be behind that? —
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com
—
Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256
You are currently subscribed to ntdev as: unknown lmsubst tag argument: ‘’
To unsubscribe send a blank email to xxxxx@lists.osr.com