Considering Decklink; unsure about several things.

[Luke Maslen]

Hi Eric,

[Eric Steinberg] “1. I have heard that Decklink is mostly geared towards Mac users, and that Windows users experience some problems with Decklink. Is this true?”

No. The DeckLink cards started on Mac but have now been on Windows for some years and the drivers are mature. We aim for feature parity between Mac and Windows but there are some fundamental differences between the two platforms and the software available on those platforms. In some areas our Windows drivers are ahead and in others our Mac OS X drivers are ahead.

We began with QuickTime drivers but then added DirectShow so that anyone who wants to can hook in to our DirectShow filters and write their own custom applications. One prominent example is Sony Vegas 6.0c which is specifically written to hook in to the DirectShow support in our drivers. DeckLink cards are the only SDI cards supported by Sony in Vegas.

We’ve also written our own plug-in to Premiere Pro 1.5.1 so you can use DeckLink cards with Premiere Pro and also control the deck via built-in RS-422 deck control without having to purchase any additional software or hardware.

The QuickTime support is useful with applications including After Effects and Combustion.

[Eric Steinberg] “The Matrox AXIO supports native DVCPro HD editing in Premiere, but what about Decklink?”

Aside from our own uncompressed codecs, we support whatever codecs are available with Premiere Pro. Unfortunately Premiere Pro does not currently include a DVCPRO HD codec so you cannot edit in that codec without purchasing an expensive add-on codec. Hopefully that might change in the future in the same way that Apple include the DVCPRO HD and HDV codecs with Final Cut Pro.

However if your camera has HD-SDI output, then you can use DeckLink to capture to an uncompressed 8 or 10 bit timeline for maximum quality. You can add effects, text, transitions and render without any degradation in quality as it is uncompressed video.

[Eric Steinberg] “Someone told me that with a Decklink card, the DVCPro HD footage would be re-compressed, so I would in effect lose a generation. Is this true?”

I would need more context to understand what they were saying. DVCPRO HD is a compressed format. It looks great but if you compress and recompress it, it will soon degrade in quality as will any compressed codec.

When you capture via SDI to the DeckLink card, you will capture to an uncompressed 8 or 10-bit timeline. You can render as much as you like and it will not degrade in quality. When you are finished editing, you can then output to deck. If you output to a Panasonic D5 deck, your video should remain at very high quality as it uses little compression. However if you were to output to a DVCPRO HD deck, it would recompress in to the tight DVCPRO HD format and this would lead to some degradation in quality. That is the nature of the codec.

In fact if you were working in Premiere Pro using a DVCPRO HD codec, then you would find that any effects and renders you applied would cause generational loss.

When working with DVCPRO HD material, the choice is either to capture in natively (no loss) and then edit it (with generational loss) or else capture to an uncompressed timeline. If you capture to an uncompressed timeline, the DVCPRO HD material will decompress once (loss) but then there will be no further loss unless you output back to a DVCPRO HD deck in which case it will be compressed again.

Both workflows have their merits in different situations.

If you want to work in DVCPRO HD format with a DeckLink card, then currently the solution would be to use Final Cut Pro HD on a PowerMac G5.

[Eric Steinberg] “If I choose Decklink, which card should I buy? I want to be able to capture just about anything, both SD and HD, since clients bring all kinds of formats (From analog VHS to Digibeta). I want the quality to be as good as possible, and I want to be able to edit the captured material in Premiere (real-time) and After Effects.”

I would suggest any DeckLink HD series card, including the entry model $595 DeckLink HD, combined with the $1995 Multibridge. The DeckLink HD card is all digital and has SD/HD-SDI input and two outputs. The Multibridge is a birdirectional digital-analog convertor which can be used to support older analog decks. It will convert the analog video and audio in to SD-SDI and HD-SDI which can then be captured with the DeckLink HD. The DeckLink HD can then output through the Multibridge to analog decks such as Betacam SP.

You can even use the Multibridge to convert the uncompressed component analog outputs of a HDV camera in to HD-SDI so you can work in an uncompressed format rather than the tricky HDV format.

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We support realtime capture and playback of uncompressed SD and HD video in Premiere Pro as well as realtime capture and playback of DV video. AVI files captured in Premiere Pro can be moved to and from After Effects and we also support RAM preview out of After Effects to the DeckLink display on your broadcast monitor.

If you work in uncompressed formats, there will be no degradation of quality of your source material. That is why DeckLink cards and Multibridge are designed to work as uncompressed 10-bit SDI cards to retain maximum quality through all stages of a workflow.

Regards,

Luke Maslen
Blackmagic Design

[Eric Steinberg]

Thank you for your detailed and very informative reply! I now feel that the Decklink solution could work just fine for me. Like I said, I’m considering the AXIO system as well, and once I add up the cost of the Decklink/Multibridge, drive arrays, etc. etc, I’ll see how much of a savings the Decklink solution will be. The savings would be the main reason to choose Decklink over AXIO, as far as I can see. But maybe there are some things I can do with Decklink that I couldn’t do with AXIO? If that’s the case, I sure would like to know… 😉

Kind regards,
Eric