ivtv-driver : 1.4.1
I've written a threaded recording server that makes use of one or more TV-
capture cards (e.g. Hauppage 150, 350 etc) to do scheduled recordings
+transcodings.
I'm just now running through all kinds of tests and basically it works as it
should. I'm testing it on a server with both a 350 and a 150 (Hauppauge analog
MP2 capture cards)
However, I have occasionally seen issues which I interpret as driver "lockups",
i.e.
1) The card opens fine. (open() returns a valid descriptor)
2) The settings made to the card (tuner freq. bitrate etc) seems to work, i.e.
they give no error.
3) However, the read/write loop (which is based on select()/read()) gives a
timeout on the select() waiting for the video descriptor to indicate that it has
some data available to be read by a a subsequent read() call.
The problem is that this is an intermittent issue, i.e. the capture works fine 9
times out of 10.
This issues seems related to changing HW parameters on the card too often (e.g.
MP2 bitrate). so if I just open the driver (e.g. /dev/video0) and just use the
default parameters it seems to work fine 10/10 and not just 9/10. It looks like
an issues to change the parameters too frequently.
At least that is how it looks viewing the driver as a "black box"
Sometimes I have also got an EBUSY when I try to change the MP2 video bitrate on
a just opened card.
Can anyone comment on these thoughts:
-----------------------------------------------------
0. Does the open() call do some kind of a soft reset on the capture card?
1. Is there some HW limitations to when/and how often the MP2 parameters can be
set (i.e. why is some controls returning EBUSY when the card has been
succesfully opened and no other apps are using the card). If I only set the
tuner freq. but stay away from the bitrate etc. it seems to just work always.
2. I guess it could be a heating issue, but the server has _very_ good
ventilation so I find this hard to believe. Especially since once a recording
have started it can run for hours wihtout any problems and very good picture
quality.
Cheers,
Johan
HW Details:
04:05.0 Multimedia video controller: Internext Compression Inc iTVC15 MPEG-2
Encoder (rev 01)
Subsystem: Hauppauge computer works Inc. WinTV PVR-350
Flags: bus master, medium devsel, latency 64, IRQ 21
Memory at dc000000 (32-bit, prefetchable) [size=64M]
Capabilities: [44] Power Management version 2
Kernel driver in use: ivtv
04:06.0 Multimedia video controller: Internext Compression Inc iTVC16 (CX23416)
MPEG-2 Encoder (rev 01)
Subsystem: Hauppauge computer works Inc. WinTV PVR 150
Flags: bus master, medium devsel, latency 64, IRQ 22
Memory at d8000000 (32-bit, prefetchable) [size=64M]
Capabilities: [44] Power Management version 2
Kernel driver in use: ivtv
_______________________________________________
ivtv-users mailing list
ivtv-users@ivtvdriver.org
http://ivtvdriver.org/mailman/listinfo/ivtv-users
I've written a threaded recording server that makes use of one or more TV-
capture cards (e.g. Hauppage 150, 350 etc) to do scheduled recordings
+transcodings.
I'm just now running through all kinds of tests and basically it works as it
should. I'm testing it on a server with both a 350 and a 150 (Hauppauge analog
MP2 capture cards)
However, I have occasionally seen issues which I interpret as driver "lockups",
i.e.
1) The card opens fine. (open() returns a valid descriptor)
2) The settings made to the card (tuner freq. bitrate etc) seems to work, i.e.
they give no error.
3) However, the read/write loop (which is based on select()/read()) gives a
timeout on the select() waiting for the video descriptor to indicate that it has
some data available to be read by a a subsequent read() call.
The problem is that this is an intermittent issue, i.e. the capture works fine 9
times out of 10.
This issues seems related to changing HW parameters on the card too often (e.g.
MP2 bitrate). so if I just open the driver (e.g. /dev/video0) and just use the
default parameters it seems to work fine 10/10 and not just 9/10. It looks like
an issues to change the parameters too frequently.
At least that is how it looks viewing the driver as a "black box"
Sometimes I have also got an EBUSY when I try to change the MP2 video bitrate on
a just opened card.
Can anyone comment on these thoughts:
-----------------------------------------------------
0. Does the open() call do some kind of a soft reset on the capture card?
1. Is there some HW limitations to when/and how often the MP2 parameters can be
set (i.e. why is some controls returning EBUSY when the card has been
succesfully opened and no other apps are using the card). If I only set the
tuner freq. but stay away from the bitrate etc. it seems to just work always.
2. I guess it could be a heating issue, but the server has _very_ good
ventilation so I find this hard to believe. Especially since once a recording
have started it can run for hours wihtout any problems and very good picture
quality.
Cheers,
Johan
HW Details:
04:05.0 Multimedia video controller: Internext Compression Inc iTVC15 MPEG-2
Encoder (rev 01)
Subsystem: Hauppauge computer works Inc. WinTV PVR-350
Flags: bus master, medium devsel, latency 64, IRQ 21
Memory at dc000000 (32-bit, prefetchable) [size=64M]
Capabilities: [44] Power Management version 2
Kernel driver in use: ivtv
04:06.0 Multimedia video controller: Internext Compression Inc iTVC16 (CX23416)
MPEG-2 Encoder (rev 01)
Subsystem: Hauppauge computer works Inc. WinTV PVR 150
Flags: bus master, medium devsel, latency 64, IRQ 22
Memory at d8000000 (32-bit, prefetchable) [size=64M]
Capabilities: [44] Power Management version 2
Kernel driver in use: ivtv
_______________________________________________
ivtv-users mailing list
ivtv-users@ivtvdriver.org
http://ivtvdriver.org/mailman/listinfo/ivtv-users