Intensity Pro dropped frames

[Michielvsb]

Hello,

I recently (1,5 month ago) bought a BlackMagic Intensity Pro card and it worked well for capturing component video in 720p MJPEG. Two weeks ago I noticed dropped frames. There isn't a lag, but the previous frame is repeated, so the the video isn't played black smooth. I have tried all I can imagine. My hard drive is fast enough for capturing in MJPEG (disk speed test rates @55MB/s) My settings are correct because sometimes it works, but most of the time it doesn't. I have an nVidea 7600GS graphics card. But again, my specs should be OK because sometimes it works. I use MediaExpress 2.3 for capping. Do you know a solution?

Thanks in advance

[rcubed]

Michielvsb,
I have an Intensity Pro and I capture at 1920x1080i 59.9x. I have to use a RAID 0 with 3 drives. I recently had a dropped frame problem and it was due to other software running in the machine. I had done a defrag with Perfect Disk and had forgotten to shut down the program (it leaves a copy running in background unless you specifically shut it down). The Intensity Pro tech support indicated dropped frames are due to a latency problem writing to the HD. I shut down all other software including Zone Alarm and other programs that might be running in the background. Also if the HD is fragmented that can cause access latency writing to the HD. It is best to capture to an HD that is separate from the OS. Hope this helps. Let us know what your find out.

rcubed

[edDV]

Most of the time this will be a fragmented capture drive. Hard disk seeks are very slow.

Any other program reading/writing to the capture drive can cause drops.

As said, a 100% CPU render in the background could cause the MJPEG codec to drop. You can set higher priority to the codec in task manager processes.

[Michielvsb]

Thanks for your replies. A few days ago I reinstalled Windows 7 and the first I did was installing the drivers for my capture card and test if it worked. But it didn't, in 5 frames there was at least 1 repeated frame. The hard drive was formatted and empty (290/300GB). I know it isn't good to capture on the HDD on which my OS is installed, but my other HDD's are almost full (speed ...) or external. I think (correct me if I'm wrong) that it's better to capture on the OS HDD with almost no programs in the background (fresh install) and empty than capturing on a full drive.

The average bitrate of a MJPEG 720p is around 65000kbps (8 MB/s). Disk speed test told me the speed of my hard drive is 55 MB/s, so it looks like it should work (correct ?) Is the MJPEG codec a seperate task in the task manager ? When I capture I notice one process (of the BlackMagic program) with a CPU usage of 80% - 100%. I don't see another process active when capping.

Most of the time there aren't dropped frames in the first three minutes of the video.

Thanks in advance

My specs: note (normally my graphics card is a nVidia 6600 GS with 256MB, not ideal situation but it should be possible. I changed to test with another card)

Computer
Workgroup : WORKGROUP
Processor
Model : Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
Speed : 2.4GHz
Cores per Processor : 2 Unit(s)
Type : Dual-Core
Integrated Data Cache : 2x 32kB, Synchronous, Write-Thru, 8-way, 64 byte line size
L2 Cache : 4MB, ECC, Synchronous, ATC, 16-way, 64 byte line size, 2 threads sharing
Computer
Mainboard : Intel D975XBX
BIOS : Intel BX97510J.86A.1441.2006.1025.1410 10/25/2006
Bus(es) : X-Bus PCI PCIe IMB USB i2c/SMBus
Multi-Processor (MP) Support : No
Multi-Processor Advanced PIC (APIC) : Yes
Total Memory : 3GB DIMM DDR2
Chipset
Model : Intel 82975X Memory Controller Hub
Front Side Bus Speed : 4x 267MHz (1GHz)
Total Memory : 3GB DIMM DDR2
Channels : 2
Memory Bus Speed : 2x 334MHz (668MHz)
Memory Module(s)
Memory Module : Corsair VS512MB667D2 512MB DIMM DDR2 PC2-5300U DDR2-666 (5-5-5-15 3-18-5-3)
Memory Module : Apacer 7801G9O9K5 1GB DIMM DDR2 PC2-5300U DDR2-666 (5-5-5-15 3-20-5-3)
Memory Module : Corsair VS512MB667D2 512MB DIMM DDR2 PC2-5300U DDR2-666 (5-5-5-15 3-18-5-3)
Memory Module : Apacer 7801G9O9K5 1GB DIMM DDR2 PC2-5300U DDR2-666 (5-5-5-15 3-20-5-3)
Video System
Video Adapter : NVIDIA GeForce 6600 GT (8 PS3.0, 3 VS3.0 501MHz, 128MB DDR3 2GHz 128-bit, PCIe 1.00 x16)
Graphics Processor
Storage Devices
SAMSUNG HD103SI (1TB, SATA300, 3.5", 7200rpm, 32MB Cache) : 932GB (E
WDC WD3200JS-00PDB0 (320GB, SATA300, 3.5", 7200rpm, 8MB Cache) : 298GB (C
WDC WD10EADS-00M2B0 (1TB, SATA300, 3.5", 32MB Cache) : 932GB (D
Seagate ST31500341AS (1.5TB, USB/SATA, 3.5") : 1TB (F
WD Ext HDD 1021 1.5TB (USB) : 1TB (G
Logical Storage Devices
(E : 932GB (NTFS) @ SAMSUNG HD103SI (1TB, SATA300, 3.5", 7200rpm, 32MB Cache)
(C : 298GB (NTFS) @ WDC WD3200JS-00PDB0 (320GB, SATA300, 3.5", 7200rpm, 8MB Cache)
(D : 932GB (NTFS) @ WDC WD10EADS-00M2B0 (1TB, SATA300, 3.5", 32MB Cache)
(F : 1TB (NTFS) @ Seagate ST31500341AS (1.5TB, USB/SATA, 3.5")
(G : 1TB (NTFS) @ WD Ext HDD 1021 1.5TB (USB)
Peripherals
LPC Hub Controller 1 : Intel 82801GH (ICH7DH) LPC Interface Controller
LPC Legacy Controller 1 : SMSC LPC47M182

Operating System
Windows System : Microsoft Windows 7 Ultimate 6.01.7600
Platform Compliance : x64

[edDV]

It is never a good idea to capture to the OS drive although with laptops it is sometimes necessary to try. I used to get PIII laptops to capture DV (4MB/s) by setting a separate partition that could be easily defragmented.

A separate ATA/SATA internal capture drive operates in "bus mastering mode". This gives total isolation from OS processes for a direct (uncompressed or DV) transfer but since you are using a software MJPEG codec, your capture chain requires CPU assist. Still a separate drive eliminates competitive read/writes from other applications. This assumes disk indexing and other background processes are turned off for that drive.

RE: your situation, somewhat hopeless. You need to clear space on the capture drive, derfragment and if possible, move the existing files to the end of the drive leaving a single blank space on the fast end of the drive. Better to copy existing files to the OS drive to clear space on the capture drive.

You need a new drive or erase some files. If this will be a chronic problem, partition your next drive with a capture partition at the fast end of the drive, then store other files at the slow end. A separate capture partition can be quickly defragmented but a better policy for fast capture is to empty the capture partition before capture.

[Michielvsb]

I just did a 10-minute uncompressed SD capture. This requires a MUCH higher bitrate (150000 kbps vs 65000 kbps) but the CPU usage is only 25%. I haven't found one single dropped frame. Apart from the fact I should buy a new HDD (which I do if that's the solution), is it wrong to conclude in my case, the HDD isn't the problem but something else? If it is possible to write stuff with a bitrate twice as high as the HD MJPEG, it should be possible to write a video with a bitrate of only 65000kbps.

[edDV]

I just did a 10-minute uncompressed SD capture. This requires a MUCH higher bitrate (150000 kbps vs 65000 kbps) but the CPU usage is only 25%. I haven't found one single dropped frame. Apart from the fact I should buy a new HDD (which I do if that's the solution), is it wrong to conclude in my case, the HDD isn't the problem but something else? If it is possible to write stuff with a bitrate twice as high as the HD MJPEG, it should be possible to write a video with a bitrate of only 65000kbps.

Dropped frames happen when simultaneous processes combine statistically to interrupt disk access or CPU availability. This is far more likely to happen on the OS drive since it is always active with background processes. Remember dropped frames are usually associated with disk seeks.

I'm recommending you clear space and defragment on the capture drive rather than attempt capture on the OS drive which is a more hazzarous environment.

[Michielvsb]

I did what you advised, I installed a new HDD (120GB) in my pc and formatted it, so it was empty. I monitored the CPU of my system and at the begin, it stays around 60-70%. After a few minutes it reaches 100% and frames begin to drop. So I'm sure now the problem is the CPU and not the HDD. Does anybody know the cause of the CPU peaks?

[edDV]

Suggest you monitor processes in Task Manager for CPU activity.

[Michielvsb]

When I start capturing a 720p MJPEG clip, the CPU is around 70-80%. But after max 5 minutes it reaches 100% and frames begin to drop. Is it possible my CPU (Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz) can't handle it?

[edDV]

When I start capturing a 720p MJPEG clip, the CPU is around 70-80%. But after max 5 minutes it reaches 100% and frames begin to drop. Is it possible my CPU (Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz) can't handle it?

70-80% CPU doesn't allow much safety margin. I'd check in this order.

1. Look for other process in Task Manager using the CPU.

2. Look at the video content. More action and video complexity may require more CPU at that point in the video.

3. Try reducing the amount of compression. That should reduce CPU usage.

[Michielvsb]

There aren't other processes that uses the CPU (sometimes 1%...). After capping different types of video I saw every time after 5 minutes it began to drop (no action films). Second problem, I can't reduce the amount of compression. BlackMagic Intensity uses his own codec for the processing which can't be configurated. I've tested with uncompressed SD video and no problem. I would capture uncompressed HD but my drive isn't fast enough (I haven't got a disk array...).

It's difficult to believe that my CPU can't handle it, because MJPEG doesn't ask that much of the CPU I think (so I taught a dual-core processor should be able to handle it)

[edDV]

There aren't other processes that uses the CPU (sometimes 1%...). After capping different types of video I saw every time after 5 minutes it began to drop (no action films). Second problem, I can't reduce the amount of compression. BlackMagic Intensity uses his own codec for the processing which can't be configurated. I've tested with uncompressed SD video and no problem. I would capture uncompressed HD but my drive isn't fast enough (I haven't got a disk array...).

It's difficult to believe that my CPU can't handle it, because MJPEG doesn't ask that much of the CPU I think (so I taught a dual-core processor should be able to handle it)

I'm out of ideas why CPU use should spike after 5 minutes.

[Brad]

Are you able to use regular VFW or DMO codecs with the BMIP? Huffyuv-MT, Ut Video?

[Michielvsb]

I think I can't. In MediaExpress, the standard recording tool, it isn't possible. In VirtualDub I can choose between uncompressed video and motionjpeg (codec developed by BM, settings can't be configurated).

[Brad]

Uncompressed video, which format in VirtualDub? HDYC? Maybe try Set Custom Format and UYVY then go to Compression.

Edit: There is a discussion of BMIP in VDub here and squid_80 posted an altered Huffyuv build with HDYC support.

[milatchi]

Storage Devices
SAMSUNG HD103SI (1TB, SATA300, 3.5", 7200rpm, 32MB Cache) : 932GB (E
WDC WD3200JS-00PDB0 (320GB, SATA300, 3.5", 7200rpm, 8MB Cache) : 298GB (C
WDC WD10EADS-00M2B0 (1TB, SATA300, 3.5", 32MB Cache) : 932GB (D
Seagate ST31500341AS (1.5TB, USB/SATA, 3.5") : 1TB (F
WD Ext HDD 1021 1.5TB (USB) : 1TB (G
Logical Storage Devices
(E : 932GB (NTFS) @ SAMSUNG HD103SI (1TB, SATA300, 3.5", 7200rpm, 32MB Cache)
(C : 298GB (NTFS) @ WDC WD3200JS-00PDB0 (320GB, SATA300, 3.5", 7200rpm, 8MB Cache)
(D : 932GB (NTFS) @ WDC WD10EADS-00M2B0 (1TB, SATA300, 3.5", 32MB Cache)
(F : 1TB (NTFS) @ Seagate ST31500341AS (1.5TB, USB/SATA, 3.5")
(G : 1TB (NTFS) @ WD Ext HDD 1021 1.5TB (USB)

I don't explicitly see 10,000 RPM listed along with any of those hard disks. If none of those disks are 10,000 RPM that in itself is a problem for capturing adequately with the Intensity Pro.
Blackmagic has on their site a list of recommended video cards and motherboards for use with the Intensity Pro. They also recommend a RAID configuration of 10,000 RPM hard disks. Take it from someone who spent over a month getting a machine together for capture (following Blackmagic's recommendations) and going through 1 bad Intensity Pro card -- Blackmagic's support is actually really good if you have a problem using system that meets their recommendations. I use version 3.4 of their software to capture 720p video over HDMI to a 10,000 RPM hard disk with no problems. My hardware config. for use with the Intensity Pro can be found here:
http://milatchi.blogspot.com/