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live transcoding of HD, plus pre-recorded ingest

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lynne robinson
live transcoding of HD, plus pre-recorded ingest
on Jun 27, 2009 at 1:08:11 pm

Hello,
Several questions here, so please bear with me!:

- I have been making my first documentary using a Sony Z1 (HDV tape); I also have a Canon HF100 with which I've shot HD footage (AVCHD) onto class 6 cards.
I have a non-intel Power Mac G5 Quad (PCIe), and need to find the best way to ingest the footage into FCP.
Does anyone know if there is any advantage to capturing via HDMI capture card using the camera to play the footage? (as opposed to just using a card reader to ingest the card data, and firewire to transfer the HDV tape playing from the camera)?

- Also, I plan to get a mobile set-up where I can do a live feed into a laptop to bypass compression. I've heard that Mac laptops are not up to the job of live HD aquisition/conversion, but have discovered that PC laptops come as quads (plus 2-3 HDDs) which are more powerful. Is it ok to put a live feed into the HDMI connection which some of these PC's have, or would it still be necessary to use a capture card? If so, would a Matrox mini or Black Magic intensity (in a Magma box), or AJA card be better?

- I want to transcode to Cineform or Pro Res at the point of live capture; can I do this without FCP on the laptop?

- Would I need to use an external (esata) RAID to process and store these files, or is it ok to RAID the laptop's internal discs instead? (I won't be editing on the laptop, just capturing/transcoding/storing until I can transfer onto my desktop system)

I don't want to have to spend more money on this set-up than I absolutely have to, but I want the best quality possible too...

Help very much appreciated!
Thanks


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Craig Seeman
Re: live transcoding of HD, plus pre-recorded ingest
on Jun 29, 2009 at 3:50:42 pm

[lynne robinson] "I've shot HD footage (AVCHD) onto class 6 cards.
I have a non-intel Power Mac G5 Quad (PCIe), and need to find the best way to ingest the footage into FCP. "


G5 does not support AVHCD if I recall correctly. Of course finding a way to transcode on input might resolve that. Given the costs involved you really might consider getting an Intel Mac.

[lynne robinson] "Does anyone know if there is any advantage to capturing via HDMI capture card using the camera to play the footage? (as opposed to just using a card reader to ingest the card data, and firewire to transfer the HDV tape playing from the camera)? "

Once the video has hit the codec and recorded to camera's card, HDMI won't make it look better. I believe it won't be sending out AVCHD though so that might be a way to avoid the PPC/AVCHD issue.

A DeckLink HD Extreme should work on PPC and supports HDMI.
http://www.blackmagic-design.com/products/decklinkhdextreme/
Most other HDMI input devices don't support PPC.

Again, given the expense and the additional workflow it might be time to get an intel MacPro.


[lynne robinson] "- Also, I plan to get a mobile set-up where I can do a live feed into a laptop to bypass compression. I've heard that Mac laptops are not up to the job of live HD aquisition/conversion,"

Major wrong on that! I often wonder where does one "hear" such things because I don't see that misinfo on this or any other of the major pro video forums I hang around on. Matrox MXO2 Mini can handle HDMI input on a MacBookPro with Express card slot and 2.4GHz Core Duo processor and up. You'll be able to go to Apple ProRes.

You seem to be getting a lot of misinformation. I don't think that would be from the COW. On the other hand it's good you came here and asked because whatever your source was would probably have driven you into a nightmare workflow.

Really I think your best bet is to get Intel Macs though otherwise your ancillary expenses may well cost you at least a good portion of money (and time) that could be used on a MacPro. You can get a used 15"MacBookPro (new 15" doesn't have Express card - only 17" does) or new 13" or 15" inch which does have SD slot for straight copy of AVCHD from the camera . . . and they've added back firewire you can use for the HDV camera.





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lynne robinson
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 1:21:28 pm

Thanks for the advice.
Actually that "mis" information was indeed from The Cow:

Re: Matrox mini live transcode possibility?
by Shane Ross on Jun 27, 2009 at 8:34:13 pm

Also was told same thing at the Matrox stand at the FCPUG London meet.

Not sure what to believe anymore! If I can use a Mac laptop it would be great, because I can get free hire.
However, I don't want to pay out for the Mini and Cineform if this workflow won't work....


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Craig Seeman
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 2:10:15 pm

http://www.matrox.com/video/en/products/mxo2_mini/specs/

On a MacBook Pro Core2 Duo 2.4 GHz or faster, you can capture HD to ProRes 422 HQ (720p at 24, 25, and 30 fps) and DVCPRO HD. On systems equipped with proper storage you can capture uncompressed 8- and 10-bit HD.

It also supports PC laptops but doesn't differentiate specs for laptop.


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lynne robinson
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 4:34:31 pm

Thanks for the link; I actually had already read that before going to the FCPUG Supermeet. I went there fully expecting to be on the right track with this workflow; I certainly wasn't expecting to be discouraged by the guys on the Matrox stand of all people. That's why I tried to get clarification by posting on the Cow.
The Matrox specs only mention live transcoding on a Macbook Pro at 720p, not 1080i which was what Shane mentioned in his response (see above). Also they say 'with the proper storage you can capture uncompressed 10 bit', but of course how you store 10 bit, and how you transcode 10 bit are 2 different things....
Still confused about the truth!


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Craig Seeman
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 4:57:29 pm

There are some confusing things in the specs of the MXO2mini.
They mention ProRes HQ which requires more system resources than ProRes (non HQ). Perhaps non HQ could allow for 1080? I'll see if I can find out for you.

You'd probably need a Raid 0 drive to get 8 or 10 bit uncompressed. There are several designed for laptop use.

http://www.g-technology.com/products/g-raid-mini.cfm



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lynne robinson
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 8:04:29 pm

Slightly confused about the role a RAID plays in live capture; I was under the impression that the computer's CPU does all the hard work of ingest and transcoding the full HD, then once converted to Pro Res the footage is written to the RAID. How then is it still important that the RAID is very fast, since at that point the footage is compressed? Is it because Pro Res HQ 1080i still requires very fast write ability?


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Craig Seeman
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 14, 2009 at 8:24:23 pm

The data rate for 8 or 10 bit uncompressed is too fast for a single hard drive to handle the record. Raid 0 (drives striped together to appear as one very fast drive) is needed.

[lynne robinson] "full HD"
Avoid using terms like "full HD" HD comes in many flavors/codecs, etc.
Some codecs need fast decode/encode. Some need fast drive write times.
ProRes needs significant CPU power but is very efficient so doesn't need the drive speed that 8 bit uncompressed needs . . . which doesn't need as much CPU power.



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Darren Godwin
Re: live transcoding of HD, plus pre-recorded ingest
on Jul 23, 2009 at 2:36:51 pm

When capturing using the MXO2 encoding is being handled by FCP and the CPU it's running on. The ability to record all this data is then down to the PCIe bus, storage adapter and storage. To encode 1080i ProRes 422 HQ with confidence you need a Quad Core CPU, so basically a MacPro. For 720p and SD ProRes a MacBook Pro will do. The MXO2 will work happily with uncompressed SD/HD too. Just bear in mind that due to the much higher bandwidth (and filesize) of HD you'd have to use a fast RAID and quite a lot of it. If possible go to a dealer who sells a range of NLE products into high-end post and get friendly with them. They can advise you on your complete end-to-end workflow, integration with your existing system, and be on hand when things go wrong. The advice isn't always free but you may be able to bargain, to a degree, by offering them some great 'demo material' which dealers are always crying out for. Buying from them will always make them obliging! Good luck on the docu!


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