[Gllug] Hardware requirements for video editing?

[Rich Walker]

Chris Bell <chrisbell at overview.demon.co.uk> writes:

> Hello,
>    I have been asked about hardware requirements for grabbing and edititng
> sound and video taken with standard (non-professional) camcorders. There are
> missed frames as seen on screen trying to display replay from a digital
> camera via firewire using an Adobe package on M$, but I can not tell whether

We're very happy using firewire to talk to cameras - both expensive and
cheap ones. 

The issues that are worth having in mind:
640x512x24bppx30fps => 27 megabytes per second.
If you can compress on the fly (e.g. a K6-2-400, or equivalent) then
this is down to <10MB/s => stock IDE UDMA drive, proper hdparm settings,
*NOT* ext3 or Reiserfs, and some RAM for a buffer. (I stream from a
mini-DV recorder using firewire and Kino on a 128MB K6-2-400; hdparm
reports 15MB/s read thruut; 

lin-pc:/home/rw# time dd if=/back/zz of=/back/za bs=1048576 count=256
256+0 records in
256+0 records out
268435456 bytes transferred in 35.020107 seconds (7665181 bytes/sec)

real	0m35.152s
user	0m0.000s
sys	0m18.740s
lin-pc:/home/rw# time dd if=/back/zz of=/back/za bs=1048576 count=256
256+0 records in
256+0 records out
268435456 bytes transferred in 34.926997 seconds (7685615 bytes/sec)

real	0m35.149s
user	0m0.020s
sys	0m18.380s

is what I get with a block copy operation.

Running kino on this box is OK - it all "just works".

Just to confirm the "stock crap" nature of this box:

lin-pc:/home/rw# hdparm -i /dev/hda

/dev/hda:

 Model=ST340810A, FwRev=3.60, SerialNo=5FB7N9M8
 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=4
 BuffType=unknown, BuffSize=2048kB, MaxMultSect=16, MultSect=16
 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=78165360
 IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes: pio0 pio1 pio2 pio3 pio4 
 DMA modes: mdma0 mdma1 mdma2 udma0 udma1 *udma2 udma3 udma4 udma5 
 AdvancedPM=yes: unknown setting WriteCache=enabled
 Drive Supports : Reserved : ATA-1 ATA-2 ATA-3 ATA-4 ATA-5 ATA-6 

lin-pc:/home/rw# lspci
00:00.0 Host bridge: Silicon Integrated Systems [SiS] 5597 [SiS5582] (rev 10)
00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513 (rev 01)
00:01.1 IDE interface: Silicon Integrated Systems [SiS] 5513 [IDE] (rev d0)
00:09.0 FireWire (IEEE 1394): VIA Technologies, Inc. IEEE 1394 Host Controller (rev 43)
00:0b.0 Ethernet controller: Accton Technology Corporation SMC2-1211TX (rev 10)
00:0d.0 VGA compatible controller: Matrox Graphics, Inc. MGA 2164W [Millennium II]
00:0f.0 Multimedia video controller: Brooktree Corporation Bt848 Video Capture (rev 12)
00:14.0 VGA compatible controller: Silicon Integrated Systems [SiS] 5597/5598/6326 VGA (rev 68)



> it is just a display problem with a good recording on disc, and am
> considering either trying video 4 Linux on the same hardware, or starting
> from scratch with a new box. Options include P2/400, P3/550, dual P2/450, or
> a completely new box, perhaps with different clips held on different discs
> before editing, raid, etc..... Am I right to assume that 100MHz ethernet
> would be too slow to allow any form of parallel processing?

A P2/400 should do the job! Use several hard drives, big, and it *might*
be worth getting 7200RPM. (Last time I priced drives, for 80GB 7200 was
the same price as 80GB 5400). 

100Base ethernet is *theoretically* fast enough to stream across, but
you will just move the bottlenecks around. Other things that might make
a difference: 

don't put the hard drives on the same cable
if your firewire card is PCI, don't use a PCI IDE RAID card!

make sure the video processing software is taking advantage of the
MMX/3DNOW/SSE capabilities your CPU supports - you may need to recompile
it.

hope this helps,

cheers, Rich



> 
> -- 
> Chris Bell
> 
> 
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