SDI capture

[Ezra Peace]

Hi guys, trying to wrap my mind around the whole capture card thing once and for all (being that I don't currently use capture cards and wonder why I should). Is my understanding correct that capture cards such as the intensity/declink, and higher end Io series, bypass the camera's compression chips (such as HDV and DV) and record a much cleaner picture to your format of choice (presumably ProRes 422)? Or is this only with HDMI capture? If this is true then I should then absolutely use a card to capture video when I am capturing straight to hard disk. But I've heard of people using these cards to digitize their already HDV or DV recorded footage. Why would you do this unless you already have the card and just felt like using it? There is alot of mystery around this topic for me and the manufacturers sites aren't any help as they assume you already know this stuff when considering their products.

Also is there anyone on the list who captures video directly to a laptop? If so what software do you use? I've been using ScopeBox with limited success (straight from my camera over firewire400). Just wondering what the standard is if any? (btw I am positive there is a better way to do what I'm doing!! any insight is much appreciated). Thanks!

"If you aren't going all the way, why go at all?"    --Joe Namath

www.ezrapeace.com

[Luna Studio]

Ezra

If you come out of most cameras via SDI or HDMI you are bypassing the compress stage. There may be a couple that do not bypass compression, I will leave that to the camera guru's to chime in on.

There are many users that capture even HDV or DV tape through SDI into uncompressed or ProRes. The footage of course ends up being heavier (size and bandwidth). The idea behind capturing from SDI is to shift the footage into a higher quality editing space. If you edit in a native HDV or DV timeline you are working with a reduced palette of colors. Any effects and graphics that you create will have this reduced palette to create from. Any untouched footage does not really improve from being captured into a higher space. It comes down to whether the amount of effects and graphics created is enough to warrant the additional space and bandwidth needed. 

Orlando

--
Orlando Luna

[René Borroto]

Ezra:

Capture cards, among other functions, facilitate capturing footage from a deck or camcorder in a codec that is not native to that deck/camcorder. If you're shooting with an HDV camcorder to tape, it's already compressed to HDV, REGARDLESS of how you get the footage into your computer. The same holds true for DV. If you're shooting a LIVE event, however, you can capture from an HDMI or component output from your camera BEFORE it's compressed to HDV. The key word here is BEFORE, because again, once it's on tape, your in HDV world and you cannot get out without compression. One thing we do at our facility, when capturing footage shot in HDV is as follows:

Take the camcorder's analog component HD output/audio output and send it to the AJA IOHD (or other capture card). The AJA then converts the footage to Prores 422 HD in real time. This converts the footage into a better COLORSPACE, as Orlando mentioned, and relieves the processor intensive workflow required when working in HDV native, as well as allow you to do graphics and compositing (like greenscreen) in a higher and better quality colospace (4:0:0 to 4:2:2). HOWEVER, the footage won't look any better with this workflow; it will NEVER look better as what is on the original tape. As I said, once you went to tape, your footage quality is, in this example, HDV.

So a capture card lets you capture one the various tape compression/uncompressed formats and physical outputs like SDI or analog component, and brings the footage into your computer in a codec of choice; they give you the physical connections necessary, and the codec capabilities you want, in order to conform your footage into your project.

As far as capturing footage to your laptop (your second question), don't you use FCP2? That's what you use, but I would recommend you use EXTERNAL storage. Going to your internal drive will bog down your system, and downright won't work sometimes.

I hope I've clarified some things.

René Borroto

Senior Editor

Multivision Video & Film

305-662-6011

re...@multivisionvideo.com

www.multivisionvideo.com

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On May 4, 2008, at 6:49 PM, Ezra Peace wrote:

Hi guys, trying to wrap my mind around the whole capture card thing once and for all (being that I don't currently use capture cards and wonder why I should). Is my understanding correct that capture cards such as the intensity/declink, and higher end Io series, bypass the camera's compression chips (such as HDV and DV) and record a much cleaner picture to your format of choice (presumably ProRes 422)? Or is this only with HDMI capture? If this is true then I should then absolutely use a card to capture video when I am capturing straight to hard disk. But I've heard of people using these cards to digitize their already HDV or DV recorded footage. Why would you do this unless you already have the card and just felt like using it? There is alot of mystery around this topic for me and the manufacturers sites aren't any help as they assume you already know this stuff when considering their products.

Also is there anyone on the list who captures video directly to a laptop? If so what software do you use? I've been using ScopeBox with limited success (straight from my camera over firewire400). Just wondering what the standard is if any? (btw I am positive there is a better way to do what I'm doing!! any insight is much appreciated). Thanks!

<pastedGraphic.tiff>

[Tim Baker]

Awesome information!!!  Bang on!

 

Tim Baker

President/CEO

Chameleon Media Productions, Inc.

www.chameleonmvp.com

DBA:  Race Fan Media

www.racefanmedia.com

(239)849-3295

 

---

From: SoFla...@googlegroups.com [mailto:SoFla...@googlegroups.com] On Behalf Of René Borroto
Sent: Monday, May 05, 2008 8:54 AM
To: SoFla...@googlegroups.com
Subject: [SoFlaFCPUG] Re: SDI capture

 

Ezra:

 

Capture cards, among other functions, facilitate capturing footage from a deck or camcorder in a codec that is not native to that deck/camcorder. If you're shooting with an HDV camcorder to tape, it's already compressed to HDV, REGARDLESS of how you get the footage into your computer. The same holds true for DV. If you're shooting a LIVE event, however, you can capture from an HDMI or component output from your camera BEFORE it's compressed to HDV. The key word here is BEFORE, because again, once it's on tape, your in HDV world and you cannot get out without compression. One thing we do at our facility, when capturing footage shot in HDV is as follows:

 

Take the camcorder's analog component HD output/audio output and send it to the AJA IOHD (or other capture card). The AJA then converts the footage to Prores 422 HD in real time. This converts the footage into a better COLORSPACE, as Orlando mentioned, and relieves the processor intensive workflow required when working in HDV native, as well as allow you to do graphics and compositing (like greenscreen) in a higher and better quality colospace (4:0:0 to 4:2:2). HOWEVER, the footage won't look any better with this workflow; it will NEVER look better as what is on the original tape. As I said, once you went to tape, your footage quality is, in this example, HDV.

 

So a capture card lets you capture one the various tape compression/uncompressed formats and physical outputs like SDI or analog component, and brings the footage into your computer in a codec of choice; they give you the physical connections necessary, and the codec capabilities you want, in order to conform your footage into your project.

 

As far as capturing footage to your laptop (your second question), don't you use FCP2? That's what you use, but I would recommend you use EXTERNAL storage. Going to your internal drive will bog down your system, and downright won't work sometimes.

 

I hope I've clarified some things.

 

 

Ren頂orroto

Senior Editor

Multivision Video & Film

305-662-6011

re...@multivisionvideo.com

www.multivisionvideo.com

 

This message (including any attachments) is intended only forthe use of the individual or entity to which it is addressed andmay contain information that is non-public, proprietary,privileged, confidential, and exempt from disclosure underapplicable law or may constitute as attorney work product.If you are not the intended recipient, you are hereby notifiedthat any use, dissemination, distribution, or copying of thiscommunication is strictly prohibited. If you have received thiscommunication in error, notify us immediately by telephone and(i) destroy this message if a facsimile or (ii) delete this messageimmediately if this is an electronic communication.

 

Thank you.

[Ezra Peace]

Thanks for the replies orlando and renee I think I'm much more clear on the subject now. So the main purpose of the capture card is to expand your format and color space options going into your NLE. This does not necessarily mean you will have an improved picture depending on the nature of your initial acquisition to tape or hard disk correct? 

So in the case of 4:1:1 footage, the capture card will convert it to 4:2:2 (or whatever you set) but if there is any stair stepping it will still need to be smoothed? Or will the conversion smooth it for you, making it ready for keying?

Am I closer to nirvana on this one? 

"If you aren't going all the way, why go at all?"    --Joe Namath

www.ezrapeace.com

On May 5, 2008, at 8:53 AM, René Borroto wrote:

Ezra:

Capture cards, among other functions, facilitate capturing footage from a deck or camcorder in a codec that is not native to that deck/camcorder. If you're shooting with an HDV camcorder to tape, it's already compressed to HDV, REGARDLESS of how you get the footage into your computer. The same holds true for DV. If you're shooting a LIVE event, however, you can capture from an HDMI or component output from your camera BEFORE it's compressed to HDV. The key word here is BEFORE, because again, once it's on tape, your in HDV world and you cannot get out without compression. One thing we do at our facility, when capturing footage shot in HDV is as follows:

Take the camcorder's analog component HD output/audio output and send it to the AJA IOHD (or other capture card). The AJA then converts the footage to Prores 422 HD in real time. This converts the footage into a better COLORSPACE, as Orlando mentioned, and relieves the processor intensive workflow required when working in HDV native, as well as allow you to do graphics and compositing (like greenscreen) in a higher and better quality colospace (4:0:0 to 4:2:2). HOWEVER, the footage won't look any better with this workflow; it will NEVER look better as what is on the original tape. As I said, once you went to tape, your footage quality is, in this example, HDV.

So a capture card lets you capture one the various tape compression/uncompressed formats and physical outputs like SDI or analog component, and brings the footage into your computer in a codec of choice; they give you the physical connections necessary, and the codec capabilities you want, in order to conform your footage into your project.

As far as capturing footage to your laptop (your second question), don't you use FCP2? That's what you use, but I would recommend you use EXTERNAL storage. Going to your internal drive will bog down your system, and downright won't work sometimes.

I hope I've clarified some things.

René Borroto

Senior Editor

Multivision Video & Film

305-662-6011

re...@multivisionvideo.com

www.multivisionvideo.com

This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication.

Thank you.

<unknown.gif>

[René Borroto]

Let me correct my statement about HDV colorspace;  it's 4:2:0, not 4:0:0 as I stated in my posting before.... oooops..

René Borroto
Senior Editor
Multivision Video & Film
305-662-6011
re...@multivisionvideo.com
www.multivisionvideo.com

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[René Borroto]

Ezra:

What do you mean by "stairstepping"?  If you're looking at a field from an interlaced frame it would look that way, mainly on diagonal edges. If you look at a field from a progressive frame you won't get that effect. Transcoding from one codec to another won't change that.

René Borroto
Senior Editor
Multivision Video & Film
305-662-6011
re...@multivisionvideo.com
www.multivisionvideo.com

***FTP FILE PREVIEW INSTRUCTIONS***   If we've included a link above so you can view a movie of your project, please click it once. It will take you to a folder with the file(s) available for download to your local computer. Simply drag and drop the file onto your desktop, or another location on your local drive. Files with a .mpg extension usually require Quicktime® Player (Mac or PC). Files with a .wmv extension require Windows® Media Player. Please wait for your file to finish downloading before trying to open/play it.

This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication.

Thank you.

On May 5, 2008, at 11:51 AM, Ezra Peace wrote:

Thanks for the replies orlando and renee I think I'm much more clear on the subject now. So the main purpose of the capture card is to expand your format and color space options going into your NLE. This does not necessarily mean you will have an improved picture depending on the nature of your initial acquisition to tape or hard disk correct? 

So in the case of 4:1:1 footage, the capture card will convert it to 4:2:2 (or whatever you set) but if there is any stair stepping it will still need to be smoothed? Or will the conversion smooth it for you, making it ready for keying?

Am I closer to nirvana on this one? 

[Ezra Peace]

Sorry . . what i mean by stairstepping is the undesirable effect that happens to DV (or any 4:1:1 footage) because the chroma information is 1/4 the luma. You get a sort of "stairstep" effect on the color (especially on the edges). 

Here's an example. It's not a great example because I think it might actually be 4:2:0 instead of 4:1:1 but I think you know what I'm referring to.

There are plugins (such as dvmatte and nattress chroma smoother) that are designed to smooth this effect on the chroma layers making keying possible on 4:1:1 footage. Im curious to know if capturing 4:1:1 footage into a format that supports 4:2:2 color space would smooth this effect. I'm guessing not since the new format would not alter the appearance of the footage in any way, just the working space?

"If you aren't going all the way, why go at all?"    --Joe Namath

www.ezrapeace.com

On May 5, 2008, at 4:45 PM, René Borroto wrote:

Ezra:

What do you mean by "stairstepping"?  If you're looking at a field from an interlaced frame it would look that way, mainly on diagonal edges. If you look at a field from a progressive frame you won't get that effect. Transcoding from one codec to another won't change that.

René Borroto
Senior Editor
Multivision Video & Film
305-662-6011
re...@multivisionvideo.com
www.multivisionvideo.com

***FTP FILE PREVIEW INSTRUCTIONS***   If we've included a link above so you can view a movie of your project, please click it once. It will take you to a folder with the file(s) available for download to your local computer. Simply drag and drop the file onto your desktop, or another location on your local drive. Files with a .mpg extension usually require Quicktime® Player (Mac or PC). Files with a .wmv extension require Windows® Media Player. Please wait for your file to finish downloading before trying to open/play it.

This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication.

Thank you.

<Multivision_Logo.gif>

[René Borroto]

This "stairstepping" that you're referring to is anti-aliasing, at least based on the pic you posted. This happens on all digital footage, and it's amount varies depending on the quality and resolution of the format and camera. The higher the resolution, the greater the number of "steps" and the smaller that each step is. That brings us to "color sampling."  The higher the sampling rate, the smaller the pieces, or samples.

Think of it as a tile mosaic. The smaller the individual tiles, the greater the detail that you can illustrate in the mosaic. You can never have "continuous tone," such as with film, but you can get closer and closer the higher the resolution. You can "approximate" smooth continuous tone and get ever closer, but you'll never quite be there, and no filter in the world will give you 4:4:4, or even 4:2:2 quality from 4:2:0 colorspace.  I say we stop here and avoid a conversation about quantum physics and calculus!!

I hope this makes some sense.

René Borroto
Senior Editor
Multivision Video & Film
305-662-6011
re...@multivisionvideo.com
www.multivisionvideo.com

***FTP FILE PREVIEW INSTRUCTIONS***   If we've included a link above so you can view a movie of your project, please click it once. It will take you to a folder with the file(s) available for download to your local computer. Simply drag and drop the file onto your desktop, or another location on your local drive. Files with a .mpg extension usually require Quicktime® Player (Mac or PC). Files with a .wmv extension require Windows® Media Player. Please wait for your file to finish downloading before trying to open/play it.

This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or may constitute as attorney work product. If you are not the intended recipient, you are hereby notified that any use, dissemination, distribution, or copying of this communication is strictly prohibited. If you have received this communication in error, notify us immediately by telephone and (i) destroy this message if a facsimile or (ii) delete this message immediately if this is an electronic communication.

Thank you.

On May 5, 2008, at 5:31 PM, Ezra Peace wrote:

Sorry . . what i mean by stairstepping is the undesirable effect that happens to DV (or any 4:1:1 footage) because the chroma information is 1/4 the luma. You get a sort of "stairstep" effect on the color (especially on the edges). 

Here's an example. It's not a great example because I think it might actually be 4:2:0 instead of 4:1:1 but I think you know what I'm referring to.

There are plugins (such as dvmatte and nattress chroma smoother) that are designed to smooth this effect on the chroma layers making keying possible on 4:1:1 footage. Im curious to know if capturing 4:1:1 footage into a format that supports 4:2:2 color space would smooth this effect. I'm guessing not since the new format would not alter the appearance of the footage in any way, just the working space?