HDV and ProRes

[Mike Paunovich]

I have a project that I am resurrecting and want to know what's the best way to convert my HDV footage to ProRes. I have half the tapes already imported as HDV. Should I trash the files and import/convert via FireWire? Or can/should I convert the loaded files?

[Eric Darling]

I don't think you can convert on the fly via FireWire. You can, however, export an HDV tape from a player via component or HD-SDI (if so equipped) into a BlackMagic or AJA card, you can go into ProRes that way.

[Michael Richard]

it's possible in FCP 6.02 to capture HDV via firewire. (at least on a MAC PRO) There are some limitations. For instance you cannot use the log and capture function, and the whole tape will be captured start to finish and break into multiple clips which you will have to log and rename.

You also have two quality options ProRes or ProRes HQ.

[Martin Pauly]

Mike,

sounds like the footage is already recorded to HDV. In that case, converting to ProRes will do just one thing: increase its size. You can't add detail in the conversion that wasn't there in the first place.

Having said that, it can make sense when working with HDV footage to use ProRes as a codec for rendering. Take a look at this post (or the entire thread, for that matter):
http://www.dvinfo.net/conf/showpost....16&postcount=7

You'd then have ProRes for transitions, effects, etc. where the extra bandwidth can make a difference, but stick with the more compact HDV format for what may be the lion's share of your project.

Now, if you were to capture straight to ProRes instead of HDV, that would be an entirely different story, but from what you wrote it doesn't sound like that's an option.

- Martin

[William Hohauser]

Originally Posted by Mike Paunovich

I have a project that I am resurrecting and want to know what's the best way to convert my HDV footage to ProRes. I have half the tapes already imported as HDV. Should I trash the files and import/convert via FireWire? Or can/should I convert the loaded files?

Just set a new sequence to ProRes in the HD flavor you are using (720p, 1080i...) and bring in the HDV files as if you are editing a regular HDV sequence. This works just fine on my five year old Dual 2ghz G5 although the sequence plays back in preview mode (lower res) during editing. You'll need to render everything eventually. I edited a mixed HDV codec sequence this way and the result was great. A benefit is that only the used footage is converted to ProRes thus saving disk space and your time.

Officially, the only Apple approved way to capture in Pro Res is with an external device from a third party company. There are some unofficial work-arounds that capture in Pro-Res without the device (do a search here) but I am sure that this is very dependent on the computer you have.

[Raymond Toussaint]

Hi,
Is there any quality difference (I assume there is not) with the original tape = HDV if you do:

a) transform HDV --> ProRes in a batch recompress
b) capture with Firewire directly to ProRes
c) create independent subclip from clip

What I do is capturing the whole tape in HDV, after that, I log and make subclips, with MediaManger delete 'not used material' and recompress to ProRes. And make subclips independent. If you do that, the subclips are no longer pointing to the original clips but became clips themself. The original clip I delete.


Is making independent subclips in HDV materal an action that loses quality? I know it makes an I-frame on the editpoint, but do the original clip and the independent subclip differ in quality? Is it just a copy, or is it recompressing and so losing image q.?


I assume: If the tape is HDV, going in batch re-compress or Firewire capturing directly to ProRes is not making any difference.

[Paolo Ciccone]

Originally Posted by Raymond Toussaint

What I do is capturing the whole tape in HDV, after that, I log and make subclips, with MediaManger delete 'not used material' and recompress to ProRes. And make subclips independent. .

Going from HDV to ProRes is transcoding with a lossy codec. That means that you will be losing quality in the conversion. More than if you just edited the clips in HDV. Asking the media manager to break the master clips and create new clips will potentially transcode as brand new GOPs have to be generated and the MPEG compression has to be re-applied. If you want to avoid loosing quality you have to use a lossless codec like Uncompressed or SheerVideo.

[Raymond Toussaint]

Hi, thanks.
That ProRes is a lossy codec I knew, but that was not the question, I wonder if there is difference in creating ProRes.

And if the media manager is to break the master clips and create new clips, is the new GOP not the same as creating edit points (new I frame so new Mpeg compression) that FCP is creating?

[Steve Oakley]

ProRes in theory is a lossly codec. in practice, not really. I've been forced to transcode HDV clips to prores because some apps don't like HDV. I've not seen anything from the trip. Apple showed pro res something like 18 generations down next to the original and it looked fine.

the best way to tell is this.

export a clip as prores, then re-import into FCP. place the original clip on V1, Pro Res clip on V2. set V2 clip composite mode to difference. you'll probably see a completely black screen, or at worst, maybe a few pixels lit up. thats all that changed. Pro Res HQ and being in 10bit is also good for color correction. no it doesn't add what was there, but it does allow for more control. its bad that apple isn't clear about when pro res is 8bit or 10bit though

[Raymond Toussaint]

Great, thanks. I noticed no difference in the testing I did. I cant see it.
For Color (FCP) I need ProRes.

I have raid space enough, and can easy start editing HDV or Prores HQ, just seeking for a way to edit, do compositing and colorcorrecting.

Seeking for the best option: doing the HDV edit + setting render effects to ProRes, or transcode HDV to ProRes after capturing. (in the same process in processing subclips to clips). I'll have to go ProRes anyway to do the cc.

[Floris van Eck]

Interesting.

I am wondering as well which workflow works best:

A

(1) Capture HDV
(2) Composition
(3) Recompress to ProRes
(4) Add graphics, titles etc.
(5) Render out to delivery format

or B

(1) Capture ProRes
(2) Composition
(3) Add graphics, titles etc.
(4) Render out

or C

Edit HDV files in a ProRes timeline.

Will I suffer quality loss in the first workflow? Or does it not degrade image quality when I recompress to ProRes halfway a project? HDV capturing gives me better options but ProRes is much easier for color correction, working with layered graphics, photos etcetera.

Editing HDV works like a charm so basically A would be a nice workflow but I would not like to degrade the image quality because HDV is heavily compressed and suffers generation loss.

[Raymond Toussaint]

interesting is to know how the ProRes effects rendering works (if you did that set up) while editing in HDV native. see this post from Nate: http://dvinfo.net/conf/showpost.php?...18&postcount=9

-Decode HDV to frame buffer
-Process effect
-Re-encode to ProRes

[Aric Mannion]

I think you can edit in HDV, and right before you make your final render change the sequence render settings to pro res and export. Is that what the post above me is getting at?

[Steve Oakley]

C, then B.... why A ? why do more work ? also you lose TC & reel name.

FWIW, you can setup a HDV TL, then in prefs have FCP render to ProRes which is much faster then rendering to HDV, and better quality.

[Floris van Eck]

So what are the right settings for scenario c?

Audio/video settings

Timeline: HDV (or should this be Apple ProRes 422?)

Capture: HDV

User preferences

Render control, render codec: Apple ProRes 422