Video corrupted in specific areas

[Phire]

I've been trying to track down what could be the cause of this problem but I can't seem to do it. What happens is that at a specific time in the video (Blue subtitles seem to trigger it in this specific video) that a specific area of the video becomes corrupted. If I use YUY2/RGB capture there is no corruption there. It always happens at the same spots, but we know it's not the video since YUY2/RGB capture doesn't show this. It only lasts up until the Blue subtitles dissapear. These subtitles are not added in by my PC, they were originally there on the video.

Here's what it looks like:



Here's my specs:

ABIT KT7-RAID
Athlon T-Bird 1GHZ
256mb PC133 RAM w/ TINYBGA Technology
Sparkle 400w Power Supply
NetGear Ethernet Card
Matrox Marvel G400-TV
IBM 45gb ATA-100, Maxtor 40gb DMA66, Quantum Fireball DMA33 (All on the RAID sockets)

Here's my IRQs:

00 System Timer
01 Keyboard
02 Programmable Interrupt Controller
03 ACPI IRQ Holder for PCI IRQ Steering
03 HPT370 UDMA/ATA-100 Controller
04 ACPI IRQ Holder for PCI IRQ Steering
04 NetGear Ethernet Adapter
05 Creative Labs Sound Blaster 16 PnP
06 Standard Floppy Disk Controller
07 ECP Printer Port (LPT1)
08 System CMOS/Realtime Clock
09 SCI IRQ used by ACPI bus
10 Matrox Marvel G400 AGP
10 ACPI IRQ Holder for PCI IRQ Steering
10 Tekram SCSI Controller
11 Creative Labs IDE Controller
12 PS/2 Compatible Mouse Port
13 Numeric Data Processor
14 VIA Bus Master PCI IDE Controller
14 Primary IDE Controller (dual fifo)
15 VIA Bus Master PCI IDE Controller
15 Secondary IDE Controller (dual fifo)

I tried to have everything not shared as much as possible. The video card is sharing an IRQ with my SCSI card, but it shared an IRQ with it in my old PC also and it never showed this problem. I never had ACPI in my old system, i'm hoping it's not the ACPI that's causing the problem.

[Marijn]

The only times I have experienced problems with subtitles is when the video signal, transmitted by the VCR was too close to the frequency one of the TV-stations. But this is only RF. If the signal you use is composite or S-vhs, there shouldn't be a problem. Else you could try to disconnect the cable from the wall and then play from the VCR.

[Phire]

The signal is directly from an SVHS video. A tech from Matrox says it's my SCSI card conflicting with the video card, but somehow I doubt that. It only seems to do this problem with this specific video, i've never seen this problem before. My old PC had the SCSI card shared as well, and it never displayed this problem. The only thing new that is sharing with it now is ACPI, and ACPI is a big hassle to remove. If I capture using YUY2 this problem wont show up, I would just capture in HuffYUV all the time but the problem is that the system gets unstable after a while when capturing that way. I get a general protection fault about 9 minutes into capture on RRAPI.DLL or it blue screens. MJPEG capture seems stable.

[Dr Mordrid]

It could well be bandwidth issue. A VIA chipset combined with a Highpoint controller isn't a good sign. Also, are those drives configured into a single array or are they set up as single drives?

You don't see these when using uncompressed formats because these are DCT compression errors. Obvious by their blocked shape.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 29 December 2000).]

[Phire]

They're single drives, I just tried capturing in 352x240 MJPEG and it does not show this problem. So does this confirm is a bandwidth problem? and if so what could I do to resolve it.

[This message has been edited by Phire (edited 29 December 2000).]

[Dr Mordrid]

What we are discussing is PCI bandwidth. Too many devices or the use of too many devices that demand a lot of PCI resources is the problem. Some devices, however, use more than they should. The old ATA33 Fasttrak had this issue, but it wasn't a problem until a lot of other devices appeared on the PCI bus a couple of years ago (BUS mice, USB etc.).

To the extent that using low bandwidth and uncompressed captures reduced or eliminated the problem it sure looks like reducing your PCI utlization would help. You can reduce it several ways;

1. make an editing-only custom user profile with all PCI resources but your video devices disabled in the Device Manager. This means LAN cards, USB (if possible), SCSI controllers not used for video etc.

2. avoid VIA chipsets. They have known problems with PCI bus throughput, which puts you behind the 8 ball to start with. Yeah, I know.... Hopefully the AMD 760 chipset will fix this for Athlon users.

3. disable all special features of your audio card, especially if it's a PCI unit. This includes the ISA emulation mode, spatial, reverb etc.

4. if possible turn down the PCI latency of your Highpoint RAID feature. This is possible with the Fasttrak, but I'm unsure about the Highpoint....

5. IF the Highpoint uses a SMART feature to check the drives integrity turn it OFF. This is a huge resource hog. Also turn SMART off in the BIOS if possible.

6. perform the "usual" filesystem optmizations as listed here;

http://www.matrox.com/mga/support/fa.../video4.cfm#33

That should get you started....

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 29 December 2000).]

[Phire]

Ok, I don't quite get how the Hardware Profiles option works in Windows, i've never used it before.. I tried copying my original profile then trying to disable some devices, but when i came back all my devices were disabled in both the original and copied profile.

Unfortunatly I couldn't find any option to change the latency on the controller, only options I saw in the Highpoint BIOS was Selecting the boot drives, making arrays and setting the drive modes.

I could put the drivers on the other onboard controllers, I think IDE 3 and 4 are the ones on Highpoint, but if I do that I think it also removes my ATA-100 support.

[This message has been edited by Phire (edited 29 December 2000).]

[wkulecz]

ATA100 isn't worth anything if its what is causing your data corruption or dropped frames!

I have no trouble capturing 3.6 MB/sec DV to ATA33 drives. Best quality Marvel MJPEG should be about the same data rate.

Hogging resources to look good on benchmarks can interfere with the high thruput and short latency requirements of multimedia. Matrox did this with one of their first PCI Millineum video boards -- you had to diable some acceleration features to get smooth DVD playback.

--wally.

[Phire]

I've done some more testing. I tried disabling as much as possible in the devices list, basically only the most needed things were left, such as KB, monitor, mouse, video card, sound card and hd controller. It didn't make a difference at all. I can't find any "SMART" or PCI Latency options for the controller so i'm guessing it doesn't support those options.

One thing that I did find out is that if I lower the MJPEG quality to Medium w/ 704x480 then it won't show the corruption OR I can set the resoultion to 352x240 and have the MJPEG quality set to highest and it won't show that corruption. Quite weird, can anyone link this to an exact problem? I'll try moving my SCSI card later on so it doesnt share with the video card (Even though I disabled it in system devices to test) and I'll try moving the HD's to the other onboard IDE slots (IDE1, IDE2).

[Phire]

Ok I think i've tried everything possible and nothing seems to fix this problem. I disconnected the SCSI card from the puter so the Marvel had it's own IRQ, the problem still appears. It can't be the highpoint controller becuase if I go into preview mode the problem is still there, unless the preview mode uses your hard drive? One thing i've noticed is that i've only had this problem with SVHS tapes, and only at times when subtitles appear, it's quite weird becuase these subtitles are part of the video and not entered into the video any special way, but I think the distortion gets triggered whenever there is any heavily shadowed text as there is in the picture above, if there is text with just outlines then it has no problems. The only thing sharing with the Marvel now is just ACPI. It's not the cables or the VCR, becuase as I stated above, I CAN get it to capture without these problems if I use specific settings, such as setting the quality to Medium in 704x480 or reducing the resoultion. RGB capture will not show this at full resoultion, the problem also dissapears with the unsupported YUY2. Which also brings me to mention that I fully reinstalled the video card drivers to their latest versions and still made no difference. I'm stumped on this one, someone try and help me please.