#DC1tv comments
A copy of comments to from MIRO that I hope will prompt some conversation and
solutions here:
Thank you for your comments Rainer (MIRO),
>>>probably HDSPEED gives no correct values because of the activated
cache options for your harddisk.
We experienced it very difficult to get 100% results with actual SCSI
controllers because of the poor Windows 3.11 support of most of these devices.
The best capture and playback results will be accessed with Enhanced-IDE
controllers and the corresponding HDs.<<<<
Alot of us Miro users are also SCSI based so I think that a well-laid
out plan for optimizing SCSI systems would enhance the loyalty of your
customers considerably. Certainly it would me.
This may not be a hard drive problem!! When I work with FIXED MJEPG
quality (which should be the best indicator of the what the system is capable
of, right??) I get the same results wether I digitize to RAM or to Hard Disk.
In both cases the maximum quality with no frame drop is 87% (I'm digitizing
from Hi-8, a Y/C signal). I have seen MACs do much better. Are Pentiums
limited??
Or, is it possible that DMA rate is too small or slow (I do not
understand this very well… llet alone how to vary it)?? Does the DC1tv have
a memory cache that can be increased?? Is this a limitation of your MJEPG
digitizing chip??
!! Is there a way to make sure that the data is passing through the PC
itself with no bottlenecks?? !!
Some specific questions:
>In the place where you set the video format (Premiere / Movie
Capture / Recording Options / Video Format /… I select> 320×240; 0
cropping; image format: MJPEG; mjpeg options: automatic quality control, data
rate= 450, mjpeg start quality= 95%. The Question: What does data rate mean??
What effect does it have??
There was an article in NEW MEDIA (November) which reviewed all the
video cards and rated Miro at the top ( I bought the card based on that).
They make recommendationsfor how to tune the capture cards.
I would very much appreciate your comments and help in implenting them
(The quoates form the article begin with ** ; My questions to you with ??
**ennable 32 bit file, BUT NOT 32 BIT DISK, access**
?? why not 32 bit disk as well, I've tired that and it seems
faster with 32 bit disk too??
**Use Smartdrv carefully (/R) or turn it off. Turn off double
buffering**
??why turn off double buffering??
**Optimize your SCSI BIOS, set sync negotiation and the highest DMA
transfer rate that doesn't crash your computer**
??As I said I'm from the Amiga. I'm completely lost here. Can
you tell me how to do this??
**Shadow the ROM BIOS of your grphics display and SCSI adapter to RAM,
but watch out for conflicts with your capture card memory
exclusion.**
??Again, I'm completely lost here. Can you tell me how to do
this??
**Get rid of TSRs that may cause interrupts. Creat a special boot
sequence for video work.**
??Again, I'm completely lost here. Can you tell me how to do
this??
**Once you've optimized your harware setup for video, run MEMMAKER to
load devices into upper memory blocks and free up conventional
memory.**
??I know how to do this??
**Use EMM386.exe with nNOEMS, and carfully set memory exclusions
required by your video card. X=D000 is often best. Look for conflicts with
the SCSI and graphics BIOS, typically C000.**
??I have done this??
**IRQ conflicts are the most common problems in your system. Best IRQs
for capture cards: 10,12,15.**
??I have done this??
**In Pentium machines, go into the motherboard BIOS and disable the
same memory areas there to prevent plug and play cards from
grabbing them. Also, mark the IRQs for your video cards as USED or
ISA.**
??I don't have any "plug and play" cards so would prefer not to
mess around with the motherboard BIOS?? ??How do I "mark the IRQs
as used??
**Don't use the modeswitch feature on advanced graphics cards that let
you change resolution without rebooting your Windows. It eats
memory.**
??I use an ATI card (PCI) with 2mg ram. I would love to be
able to see 30frames/sec on the computer screen. Would the
ATI do that with 4mg?? Or do I need a special card from Miro??
**Turn off energy sonservation features in Green PCs.**
??I have a green PC… I need to look at their
documentation to see how to disable that??
I plan to upgrade to a 60field/sec 640×480 card as soon as I can get
reliable testimony as to the quality of the various cards. I have heard that
Miro is coming out with a DC2tv card which will have those characteristics. Is
that true? How soon? I've spoken with a few companies here in the U.S. which
are coming out with cards in May/June. Those will be best adapted for SCSI.
Will your new card be IDE based or SCSI?? To do the work I want to do I need
the size and speed of SCSI fast/wide. Micropolis seems the way to go… but I
am waiting to see. IDE seems too limited in the long run.
The Miro card is well designed but I want & need higher quality video
output (By the way, I came to PCs from the Amiga, a much loved machine, on that
platform there is VLAB MOTION, also a German Co. The output from that card is
superb! at roughly the same cost as Miro's card… it is a full 640×480 60
fields/sec).
I would very much like to clear up the quality limitation with my
machine. This seems to be an issue for Miro to address… Its hard to think
of going to an even more data intensive setup if my PC can't handle this one
currently.
I also can't believe that my system is so limited… since word from
others is that they get much higher qualtiy video out of P90s
Please reply,
Thank you for your help,
Tom