Video Jerk in Playback

[Luke Maslen]

Hi Sheldon,

Have you always had this problem using the DeckLink cards or is this a new problem. If the problem used not occur, can you tell me what software versions of FCP, DeckLink, QT and Mac OS X you were probably running at that time? We can then run tests with the older and new software and this should help us to pinpoint the problem.

Regards,

Luke Maslen
Blackmagic Design

[Sheldon Pilot]

Hi Luke:

It has been there from the start. We’ve followed the recommended upgrades over the past 5-6 months for all applications thinking that the problem would correct itself, and nothing so far has resolved the issue. I can send you a frame grab to show you what I am speaking about. Please advise where I can send you an email with a jpeh attachment.

Best,
Sheldon Pilot
Sr. Producer/Project Manager
AVHb2b Communications/Ogilvy
Toronto, Canada

[Sheldon Pilot]

Hi Luke:

We have now applied a de-interlace filter from within FCP 5.0.3 to our footage and when the QT was created it has solved the problem. As mentioned previously, in playback within FCP 5.0.3 and on a print preview there are no issues. The issue only occurs when creating a QT file from the FCP 5.0.3 rendered sequence. QT compression must not like the file it is creating as it transfers the two fields to the QT which unlike television separates the two fields. We even played back the QT with the two fields on a television monitor and you could clearly see the two fields. When we applied the de-interlace filter to the original QT with the two field issue the problem was solved? If you can figure this one out you should share your results with the rest of us because this is an issue that I am seeing on both the HD card and the SP card when creating QT’s either from a sequence or from log and capture. I’m not saying this is a Blackmagic issue as it could very well be something involving Apple’s FCP/QT and Blackmagic. My concern is that we will have to now create a final sequence for output to digital or analogue tape without the de-interlace filter applied and one for digital file compression such as mpeg II’s and streamed files with the de-interlace filter applied.

This is a quick fix for the moment, but hopefully you can find a solution.

I have a frame grab jpeg of the two field QT issue for your review.

Best,

Sheldon Pilot
Sr. Producer/Project Manager
AVHb2b Communications/Ogilvy
Toronto, Canada

[Paul Provost]

we’ve had problems with 8 bit sequence exports to Squeeze 4.1 that we do not see when we use 10 bit

[Luke Maslen]

Hi Sheldon,

Thank you as a picture can be very useful. Please email to support[at]blackmagic-design.com. You’ll need to change the [at] which is designed to thwart spambots.

Regards,

Luke Maslen
Blackmagic Design

[Kristian Lam]

Hi Sheldon,

What kind of compression are you using when creating the QT file from your sequence? You mentioned MPEG2s and some ofrm of video streaming codec. Was any resizing of the video done at all?

Was it done using a straight ‘export’ in Final Cut Pro (File > Export > Quicktime Movie)?

regards

Kristian
Blackmagic Design

[Sheldon Pilot]

Hi Kristian:

The QT was created from a straight export to QT codec from within FCP 5.0.3. The interlace issue has something to do with our Decklink card(s), mounted within two separate G5 systems updated to the current recommended specs, and FCP/QT, as the issue occurs at the very beginning of the process when digitising source footage from either HD or Analogue Beta SP. It also occurs if there is no footage and you have created a title and background within photoshop/After Effects and then import to FCP 5.0.3 and output to a QT. I thought it could be with the RAID drives, but we used the Huge Extreme for the HD and the Lacie 500G 2 X RAID with the Beta SP Analogue footage and the issue is on both formats and systems which are utilising Decklink cards? As mentioned, there is no issue when exporting to digital or analogue tape. The QT’s we are using are both uncompressed 8/10 bit and MPEG 4.

We are currently using the de-interlace filter when we need to create files with compression codecs. When printing to digital or analogue tape, we do not use the de-interlace filter.

P.S. The de-interlace filter corrects the issue but then creates a new one as the title graphics appear jagged and soft. One compromise to get rid of the other.

Sheldon Pilot
Sr. Producer/Project Manager
AVHb2b Communications/Ogilvy
Toronto, Canada

[Sheldon Pilot]

Hi there:

When we log and capture our source clips using the Decklink SP card with a Beta SP PVW-2800 player/recorder we select the ntsc 8 bit uncompressed capture setting. Upon review of the QT created from the capture with QT Player, the interlace issue appears on the footage. When the QT is viewed in FCP, we cannot see the interlace issue nor do we see it when output to a CRT monitor. Then when we add graphics which move either diagonally or horizontally to the sequence and render and save to a QT and then playback with QT Player, the interlace issue appears. When we import the QT to Sorenson Squeeze 4.1 or Compressor to create an mpeg I, mpeg II or a streamed file, the interlace issue appears.

Currently, we stumbled across a de-interlace filter within FCP 5.0.3 which we apply to the sequence and then render and write to a QT, using either the Blackmagic ntsc 8 bit uncompressed or mpeg 4-video, and the interlace issue disappears. However, the quality of the graphics within the QT with the interlace filter are not as clean as when created without the filter and the amount of time to render and ouput to a QT is more than doubled. As mentioned, this is a bandaid fix to the problem.

We have purchased a Kona LH card today along with a G5 Quad 2.5 and we will run a similar test to see if the interlace issue appears with this Kona LH card. We’ve been told by Carbon Computing here in Toronto that the issue will not appear. We currently are using the Decklink SP with all the upgrades recommended for a G5 dual 2.0 10.4.2 and the upgrades recommended by Blackmagic for the card with a 500 G 2 X RAID Lacie. We are also using the Decklink HD with a G5 2.3 10.4.2 and upgrades recommended by Blackmagic with Huge Extreme 4 X RAID and 1.6T 4 X RAID Lacie. The Decklink cards with the FCP and QT seem to have an issue with interlaced files either imported into FCP or created within FCP.

Hope this helps.

Sheldon Pilot
Sr. Producer/Project Manager
AVHb2b Communications/Ogilvy
Toronto, Canada
spilot@avhb2b.com
416-504-4393