Mailing List Archive

I like the idea. Another couple of questions I would
like to add are:

How much memory do you have?
How much Processor does Myth use total (all threads) as
reported by "top" when:

a) When you are recording without watching anything
b) When viewing TV
c) When viewing a recorded show
d) When recording and watching the show at the same time

I don't remember all that info but will resend when I
get home.

I have an AMD XP 2000+ processor with 256 MB DDR 2100.
I have an AverMedia AverTV Stereo capture card in my
PC. I use the MPEG4 codec with a quality setting of
3300 with a width and height of 640 x 480. I use audio
compression. I use ext3 as my filesystem.

I have a Maxtor 60GB 7200 rpm w. standard cache hard
drive as my storage drive and an old Fireball lct20
40GB 4500 rpm for the system.
My hdparm -tT /dev/hd? values are approx. (from memory):
Maxtor: 285/47
Fireball: 285/20

My system can view live TV without glitches. Lately
though I have noticed that when I skip forward several
jumps the video starts almost stuttering until I pause
and restart playback.

"
I have a _Intel PIII processor running at 800 MHz. I have 1capture card
in my PC. I use the
RTJPEG codec with a quality setting of defaults with a width and
height of 480x 480. I don't use audio compression. I use
ext3 as my filesystem.

I have a quantum hard drive. My hdparm -tT
/dev/hd? values are: ?

My system can view live TV without glitches.

CPU
a) When you are recording without watching anything 50-60%
b) When viewing TV ?
c) When viewing a recorded show ?
d) When recording and watching the show at the same time ?

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Is anyone running mythtv with multiple capture cards at a high
resolution (at least 480x480)? So far, all the respondents have
indicated that they only have a single capture card. Isaac has
stated that his AMD1800+ _almost_ has the horsepower for two captures
+ one view, so I'm curious with AMDs price reduction this week
(AMD2100 XP is $89, 2000 is $82, 1900 is $74, etc) which CPU will hit
the sweet spot.

NOTE: Compusa is selling the Pinnacle Studio PCTV for $29.99 after
rebates. Comes with a remote, and I've put a lircrc.example file for
the remote in CVS. I've got two of these cards, but don't have the
CPU horsepower to run two cards at the same time.


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> NOTE: Compusa is selling the Pinnacle Studio PCTV for $29.99 after
> rebates.

http://www.compusa.com/products/product_info.asp?product_code=293235

This is the second time they've pushed this card with a rebate (first
time was a few months ago), and surprisingly enough I eventually
_did_ get the rebate check.

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Are you asking to watch both cars at the same time (i.e. PiP - 2
encode/decode processes) or to have one just record while the other
watches (encodes/decodes)?

I only have one card in an Athlon 1.6...if that card didn't cost $60 to
begin with, I'd get it just to test.

Nate

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> Are you asking to watch both cars at the same time (i.e. PiP - 2
> encode/decode processes) or to have one just record while the other
> watches (encodes/decodes)?
>
> I only have one card in an Athlon 1.6...if that card didn't
> cost $60 to
> begin with, I'd get it just to test.

I think the goal is to specify a minimum CPU for two encodes for the
"encoder in the basement, viewer in the living room" situation, and
the "one server does all, two encodes + 1 viewer, all on the same
box".

- From what I remember reading over on the v4l list, someone figured
that three encoder cards at high resolution and framerate will max
out the PCI bus bandwidth, so that's pretty much going to be our
theoretical maximum unless you have a server with multiple PCI
busses. Could be wrong though; I've got 4 capture cards between my
various PCs that I could put into one box, but don't have nearly the
CPU to even start trying to figure out if it'll work.

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> busses. Could be wrong though; I've got 4 capture
> cards between my
> various PCs that I could put into one box, but don't
> have nearly the
> CPU to even start trying to figure out if it'll
> work.
>

Hmm... not knowing much more about SMP than it
requires 2 processors I ask this question:

Would a dual processor box help here? Would the
Encoding (record a show) and the Encode/Decode (Watch
TV) threads be split across the processors?

--Andrew

__________________________________________________
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Yahoo! Web Hosting - Let the expert host your site
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On 14 Nov 2002 at 8:19, Robert Kulagowski wrote:

>
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>
> Is anyone running mythtv with multiple capture cards at a high
> resolution (at least 480x480)? So far, all the respondents have
> indicated that they only have a single capture card. Isaac has

Ask me this again after the weekend as I'll be adding a second tv card to my
XP1800+ system.


--
Harondel J. Sibble
Sibble Computer Consulting
Creating solutions for the small business and home computer user.
help@pdscc.com (use pgp keyid 0x3AD5C11D) http://www.pdscc.com
(604) 739-3709 (voice/fax) (604) 686-2253 (pager)

On 13 Nov 2002 at 8:00, Robert Kulagowski wrote:

I have an AMD XP1800+ on an Epox KT133A (8kTA3Pro) motherboard, currently
with only a single capture board. I use RTJPEG at 640x480 and the default
settings for encoder (mythtv 7). My capture drive is Ext2.
I have 2 drives, a Seagate 20gb 7200rpm(system) and a Western Digital 40gb
7200rpm. The WD is strictly for mythtv capture use.

This is a 20gb Seagate Barraudda IV - 7200rpm

/dev/hda:
Timing buffer-cache reads: 128 MB in 0.69 seconds =185.51 MB/sec
Timing buffered disk reads: 64 MB in 1.70 seconds = 37.65 MB/sec
[root@marcus root]# hdparm -tT /dev/hdb

This is a 40gb Western Digital - 7200rpm

/dev/hdb:
Timing buffer-cache reads: 128 MB in 0.68 seconds =188.24 MB/sec
Timing buffered disk reads: 64 MB in 1.41 seconds = 45.39 MB/sec

> My system can / cannot view live TV without glitches.
Ehh, for the most part that's true. Some recorded shows seem to stutter on
startup during playback. Otherwise pretty good playback. Switching to Mpeg4
otoh, results in less that 30fps, it looks jerky almost like every 5 or 6th
frame is missing. Also a recorded show seems to play back at 1.5-2x (again
likely due to missing frames)

> CPU
> a) When you are recording without watching anything
dunno yet
> b) When viewing TV ?
you mean different from item D below? ie you start to watch a recording after
it's already started? no answer on this one atm

> c) When viewing a recorded show ?
approx 21%

> d) When recording and watching the show at the same time ?
standard live tv results in 80-90%


--
Harondel J. Sibble
Sibble Computer Consulting
Creating solutions for the small business and home computer user.
help@pdscc.com (use pgp keyid 0x3AD5C11D) http://www.pdscc.com
(604) 739-3709 (voice/fax) (604) 686-2253 (pager)

On Thu, Nov 14, 2002 at 10:02:42AM -0600, Robert Kulagowski wrote:

> From what I remember reading over on the v4l list, someone figured that
> three encoder cards at high resolution and framerate will max out the PCI
> bus bandwidth, so that's pretty much going to be our theoretical maximum
> unless you have a server with multiple PCI busses. Could be wrong though;
> I've got 4 capture cards between my various PCs that I could put into one
> box, but don't have nearly the CPU to even start trying to figure out if
> it'll work.

A 33MHz, 32-bit PCI bus has a theoretical maximum limit of 4 * 33 =
132MB/sec. I have no idea how much of that can be practically utilized for
video capture, but three video streams would fit with plenty of room to
spare.

--
- mdz

Just got back, hope it's not too late.
>
> For people running mythtv, if you have a minute, please send some
> feedback to the following. I'm trying to get data for the mythtv
> HOWTO regarding system hardware requirements. Obviously, once Isaac
> splits the encoder / viewer aspects, some of this might change.
>
> "
> I have an AMD processor running at 1533(XP1800+)
> I have 1 capture card in my PC. I use the
> MPEG4 codec with a quality setting of 255 with a width and
> height of 480 x 480. I use use audio compression. I use
> ext3 as my filesystem.
>
> I have a IBM . My hdparm -tT
> /dev/hda values are:

320 MB/S buffer-cached reads
17 MB/S buffered disk reads
>
> My system can view live TV without glitches.
> "
>
> Thanks to all those who respond.
>
> Bob
>