Blackmagic Forum

Hello Developers:

The image is misaligned when using DeckLink 8K Pro to capture SDI signal

We used the "DeckLink 8K Pro" capture card, which is based on Blackmagic_DeckLink_SDK_11.5.1, to develop our own application. But we found a serious problem:

SDI Mode: four sub-devices half-duplex

after a long period of signal acquisition, we had to use the "DeckLink 8K Pro" capture card, which is based on Blackmagic_DeckLink_SDK_11.5.1. Captured images will be misaligned (happens with all 4 SDI interfaces)

1. High probability of recurrence, occurring almost 4-5 times a week; (8-12 hours a day, 4 signals collected simultaneously); It's also possible to misplace it after 2 hours of use.

2. can only be restored by rebooting the operating system. Even if you use rmmod to uninstall the driver and then use modprobe to reload the driver for blackmagic, the image will not return to normal.

3. Sometimes there are problems with four SDIs at the same time, and sometimes there are problems with one or two SDIs.

4. See annex for screenshots (some of the rightmost pixels have been moved to the leftmost)

Currently our product is in the near commercial phase, but this problem occurs, looking for your support and provide Debug ideas, thank you!

Let us know as soon as you need any information on commissioning or fit issues.

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Ubuntu 18.04.4 LTS (Bionic Beaver)
Kernel: 5.3.0-28-generic
Desktop: Blackmagic_Desktop_Video_Linux_11.5.1
SDK: Blackmagic_DeckLink_SDK_11.5.1

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Root> lspci -vvv
01:00.0 Multimedia video controller: Blackmagic Design DeckLink 8K Pro
   Subsystem: Blackmagic Design DeckLink 8K Pro
   Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr+ Stepping- SERR+ FastB2B- DisINTx+
   Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
   Latency: 0
   Interrupt: pin A routed to IRQ 145
   Region 0: Memory at df300000 (64-bit, non-prefetchable) [size=1M]
   Capabilities: <access denied>
   Kernel driver in use: blackmagic-io
   Kernel modules: blackmagic_io

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Driver ->
   blackmagic, 11.5.1a14, 5.3.0-28-generic, x86_64: installed
   blackmagic-io, 11.5.1a14, 5.3.0-28-generic, x86_64: installed

Input signal format：1080 25p, 1080 50i, 1080 60i

Hello,

We have same situation with 8K Pro on our Linux servers, use kernels versions 3.10.0-*.
The problems appears after reinitialization the capturing process in several hours of work.

We tried many versions of drivers (from 11.0 to 11.7 ) and have this issue on all.
On previous cards models this problems is not appearing on the same hardware.


CPU: Intel(R) Xeon(R) CPU E3-1585L v5 @ 3.00GHz
Motherboard: X11SSH-GF-1585L
RAM: 64GB
Desktop Video: 11.7a12.x86_64
Capture: 1080i/50
Profile: four sub-devices half-duplex

Hi sir/madam:

I think this is a common phenomenon that is bound to occur with long testing.

Now our tests are more refined: using SDI input x 3 (1080 50i) at the same time, for example, will also quickly reproduce this phenomenon. When using SDI input x 2 (1080 50i) or SDI input x 3 (1080 25p), the probability of this phenomenon decreases.

So I speculate that there is a memory leak bug in the firmware, and using 1080 50i x 4 (or x3) compared to 1080 25p (x3) accelerates the appearance of the bug.

So is there a command to reset the firmware once, and when this happens, if after the reset (so you don't need to reboot the OS) the image comes back to normal, then it's 100% sure it's a firmware bug!

Thanks

We used 1080 25p x 3 SDI input (simultaneous recording), Monday through Friday, cumulative duration 43 hours, to reproduce the image misalignment problem.

So, Does anyone know how to fix it?

Hello,

This issue remains after update on Desktop Video 12.0 driver.

12.1 fix this issue, close