Converting DV-NTSC to DV CCIR 601 NTSC?

Question

Level 1

131 points

Converting DV-NTSC to DV CCIR 601 NTSC?

We're trying to provide some footage to a group who is asking us to convert our Final Cut Pro DV/DVCPro NTSC sequence to DV CCIR 601 specs (basically 720 x 480 to 720 x 486). They also included in their specs that it be encoded to Photo JPEG, lower-field dominant, 44.1 Khz audio.

We've complied and found the resulting video file, when imported into FCP, has a strobing effect-- especially where there is movement. Is there a better way to do this?

Would an export of the sequence to DV/DVCPro NTSC work? They see it as a bit soft and I tend to agree (but displayed from Final Cut on an NTSC monitor, its kind of hard to tell).

What would be the best way to provide someone who has Final Cut Pro a file that they can use without much or any loss and one they don't have to render?

Thanks!

MacPro G5, Mac OS X (10.4.11), Duo Core 2.66 Ghz, G-RAID @ 1.5 TB

Posted on Jan 29, 2009 12:55 PM

Reply

Answer 1

Jan 29, 2009 5:27 PM in response to Albeer

Do you know why they're asking for Photo JPEG/44.1kHz?

Do you know how they intend to use it? There may be a better workflow, but we'd need more info to determine that.

How are you exporting...Quicktime Conversion?...or dropping a DV-NTSC sequence into an independent sequence with your stated specs/rendering/exporting Quicktime/current settings?

"We've complied and found the resulting video file, when imported into FCP, has a strobing effect-- especially where there is movement. Is there a better way to do this?"<</div>

Are you re-importing the new clips back to your FCP or are they importing it into theirs? Either way, does the sequence it's being played back in, match the new specs (PhotoJPEG/44K)?

I've not worked with PhotoJPEG, but if the new clip properties match the sequence settings, it shouldn't need to render.

The specs you list 720x486 sound like Uncompressed 8bit (BetaSP)...except you've been asked for PhotoJPEG/44K.

I do upconverts from DV-NTSC to Uncompressed 8-bit for broadcast weekly and the result is significantly better than the DV originals. No kinds of issues you've outlined. Files sizes are 5 times bigger and rendering/exporting take longer, but the quality improvement is worth it.

Post back with more info regarding your situation...like why you're needing to deliver the specs you listed...if you can find out.

K

Reply

Answer 2

Albeer Author

Level 1

131 points

Jan 29, 2009 6:32 PM in response to Kevan D. Holdsworth

They're asking for Photo JPEG because the editor there has read on some mailing list (he won't say which one) which claims that Photo JPEG works well. He also cites that Artbeats uses it for their clips, which is true. (But then again, Artbeats footage comes from film and is compressed with Photo JPEG-- there's a big difference in film's original resolution to DV.)

From _*Artbeats FAQ*_ page:
*Why is your footage compressed with Photo-JPEG?*

+"Photo-JPEG enables us to fit the clips on CD-ROM and DVD-ROM. Without it, we would be hard pressed to find a way to deliver the product. It is used as an efficient way of storing the footage only and is not intended for playback at full speed off the CD-ROM, DVD-ROM or even from a hard drive. Users may need to re-compress the footage with a codec specific to their hardware or system.+
+Photo-JPEG is by far the least destructive of all the codecs we’ve tested. In fact, side-by side comparisons show no difference visible to the naked eye. Analysis of histograms show only a 3% difference between the original and the JPEG’d versions."+

So based on those two resources, he's bound and determined this is the "best" codec to provide him our clips. The other sticker is he uses a breakout box with component out that provides his DV footage into his system as 720 x 486. He insists the footage has to be 720 x 486 because, hey, his component system gives him CCIR 601 NTSC files (720 x 486). And ours should come to him that way too.

I agree, there is got to be a better workflow. I had been exporting the Sequence using Quicktime Conversion to Photo JPEG. But the dropping-the-DV-sequence-into-a-sequence-that-matches-his-specs idea sounds feasible. I'm inclined to provide him the file straight out of Final Cut (Export>Quicktime Movie>Self-Contained movie file) and leave the conversion process to him.

I also like your technique of upconverting from DV-NTSC to Uncompressed. I'll definitely suggest that to him. That way, he can dump it to tape and send it out via satellite.

Here's a question for you: if you were to post a digital file for say, industry professionals, to download and use as a source in their DV systems (Final Cut, Avid, etc.) what would you recommend? It's got to a relatively small file-- Uncompressed 8/10-bit files can be very large, especially when the clips are over a minute. Would you think that folks would be more receptive to larger files = higher quality to DV files = smaller files but less quality? There's bandwidth issues at stake here too so smaller files might find more support among the IT- server folks.

Thanks for your response!

Reply

Answer 3

Jan 29, 2009 7:48 PM in response to Albeer

"he uses a breakout box with component out that provides his DV footage into his system as 720 x 486. He insists the footage has to be 720 x 486 because, hey, his component system gives him CCIR 601 NTSC files (720 x 486). And ours should come to him that way too."<</div>

Well...if I read that correctly, he currently is capable of capturing DV (720x480) as 720x486. If that is the case, I'd ask him if you can provide him straight up DV and let him do the capture through his breakout box? (as you suggested you might try)

Our upconvert is specifically because our PBS distributor (NETA) requires a Beta SP quality master (4:2:2 color space/720x486). Until recently, we've only shot on MiniDV (4:1:1 color space/720x480), so the upconvert was the only way to deliver a master that they would accept. (Frankly, I was a bit surprised that this worked as well as it did).

One thing I've found, (which might relate to your workflow attempts so far) is that the edited/locked/unrendered DV sequence, has to be dropped into the 8bit sequence for rendering/exporting. IOW, I can't export a DV sequence, then drop that in an 8bit sequence, because the disparity in scan lines between 720x480 vs 720x486 will 'tear' graphics apart...particularly text.

You might also try using Compressor...not sure if it would be better or not.

As to your second question about posting digital files/file sizes. For comparison...our 55min 36sec show in DV is appx 12Gb, while the 8bit versions are about 60Gb. So a one minute clip in DV might run about 200megs, while it's 8bit version would be about 1Gb. So yes, very large files sizes for the uncompressed formats.

I'd have to leave that question to others who've worked with Photo JPEG. I'm sure I've seen Photo JPEG solutions discussed here before, but I just don't have any experience to offer with that format.

Your best bet would be to offer more details regarding your last paragraph...about what you're trying to accomplish, because there are likely several factors that would determine how you develop the best workflow.

Info to get more specific answers...like...
-how are these digital files expected to be delivered...tape? hard drives? ftp site? (we used to upload our DV shows by ftp, but the uncompressed 8bit are way to cumbersome, so we sneaker-net them on external harddrives).
-what format would be best for cross platforms...FCP/Avid/Premier/Vegas/Velocity/Edius..etc.
-what lenght are these clips expected to be...1min. / 1 hour / various
-who are the ultimate end users and how will the media be used
-what additional compressions might take place throughout the pipeline...QT / WMV / Flash / RM
-"IT / server folks" sounds to me, more like PC based systems...will this ultimately be web delivery / YouTube / output to tape / broadcast / projected in a theater...or other end deliverables.

Ultimately the end deliverable(s) will often drive the workflow, so please clarify what you/your client are trying to accomplish.

If this is a proprietary type project, just try to be generic, with as much detail as possible.

Hopefully others will chime in as well.

K

Reply

Answer 4

Albeer Author

Level 1

131 points

Jan 30, 2009 6:55 AM in response to Kevan D. Holdsworth

One thing I've found, (which might relate to your workflow attempts so far) is that the edited/locked/unrendered DV sequence, has to be dropped into the 8bit sequence for rendering/exporting. IOW, I can't export a DV sequence, then drop that in an 8bit sequence, because the disparity in scan lines between 720x480 vs 720x486 will 'tear' graphics apart...particularly text.

So I'm on the same page: I shouldn't export a DV sequence (File>Export>Quicktime Movie>Self-contained movie) and suggest that he place it into a 720 x 486 Final Cut sequence? Or there will be "tearing" issues? (We're kind of seeing that with the Photo JPEG files)

Info to get more specific answers...like...
-how are these digital files expected to be delivered...tape? hard drives? ftp site? (we used to upload our DV shows by ftp, but the uncompressed 8bit are way to cumbersome, so we sneaker-net them on external harddrives).

We're trying to provide our video as digital files via a server/download rather than driving two miles to deliver it on a Beta tape. Since both organizations have FCP, we thought we could expedite-- and save gas, time, etc.-- by providing a serviceable digital file. The question here is: in what flavor?

-what format would be best for cross platforms...FCP/Avid/Premier/Vegas/Velocity/Edius..etc.

The cross platform format question is so they can post the resulting file to a web site so others can download it and use it as a source file. Of course, they'd like to provide in a good quality codec but need to consider bandwidth as well as quality. Their solution is the Photo JPEG approach-- I'm asking, +"Is there something else?"+

-what lenght are these clips expected to be...1min. / 1 hour / various

The length is under two minutes. Never more than that.

-who are the ultimate end users and how will the media be used

The ultimate end users are broadcast news stations and their affiliates. We surmise it won't be long before the satellite uplink delivery is no longer cost-effective and video news packages will be shared like photographs that users can download and use in their publications. But for right now, we're just trying to get our packages over to them and let them decide what flavor they want to serve.

-what additional compressions might take place throughout the pipeline...QT / WMV / Flash / RM

A station might download a segment, use some footage from it and post their resulting package from their web site. Or they could post the entire package as their own news story-- nobody has an issue with that as long as it's seen and used. They will post it as Flash video, as that's what I'm seeing a lot of news web sites using (CNN, NBC, Fox News, etc.)

-"IT / server folks" sounds to me, more like PC based systems...will this ultimately be web delivery / YouTube / output to tape / broadcast / projected in a theater...or other end deliverables.

The IT-server folks control the servers and are concerned about the bandwidth. A larger file equates into more demands on the bandwidth and they don't want the download delivery of a 2 minute package affecting the bandwidth of the server. The pipe is only so big, they say.

Ultimately the end deliverable(s) will often drive the workflow, so please clarify what you/your client are trying to accomplish.

The above describes what it is we're trying to do. We supply our local client with a finished product and they, as a gatekeeper, supply it to the broadcast audience. Their default delivery is a satellite uplink and they're alternatively providing these as on-demand web downloads. Since that delivery is Photo-JPEG, CCIR 601, it seems they're asking us to provide our videos already encoded in that flavor. What we're saying is, "We'll provide you the product as an export from Final Cut-to-Quicktime movie, and you make the flavor you want to provide it in."

THANKS for your helpful consideration!

Reply

Answer 5

Jan 30, 2009 7:18 AM in response to Albeer

Sounds like you're on the right track.

Understanding all the parameters you've described, I'd simply say that providing the highest quality from your end is the best solution for further compression/delivery modes.

Hopefully others who've worked with Photo JPEG will drop in on this thread. I just don't know the format and it's qualities.

Best of luck,
K

Reply

Answer 6

Jan 30, 2009 11:19 AM in response to Albeer

Man, that's a lot to read on a tight schedule. My reactions are several.
1. You're not going to get anything better out of your sequence than what it is now.
2. You should not scale the DV to 486 lines. Rather, place it in a sequence set to 720x486 and let there be black lines at top and bottom or just at the bottom (Isn't the latter the standard FCP behavior?).
3. Make sure the DV doesn't fall on an even line, which would flip the field order.
The strobing you refer to might have to do with wrong field order.
4. PhotoJPEG at 75% compression makes some sense, but 44.1kHz audio is weird.

I'd suggest the best route is to export your sequence as-is and let them adapt it to their needs.

Reply

Answer 7

Andy Neil

Level 4

3,795 points

Jan 30, 2009 12:30 PM in response to tbrookskazoo

PhotoJPEG makes sense if you're going to a different platform/program, but you gain nothing but the 601 frame size otherwise.

In fact, Photo JPEG 100 will be roughly 2X the file size as standard DV. Since you say the whole point of the codec change is for bandwidth, you're using up more with that codec.

If they have FCP on the other end, you can provide them with 720x480 DV/NTSC and it'll edit fine without need to render in their 720x486 sequence. Why try to reinvent the wheel?

Finally, changing from 48kHz to 44.1 is just plain stupid. You are saving a minimal (negligible I'd even say) amount of space, and you open yourself up to potential sync issues.

Andy

Reply

Answer 8

Albeer Author

Level 1

131 points

Feb 1, 2009 11:32 AM in response to Andy Neil

I'm pretty much figuring it out from all the great responses and reading up on other articles on the web: the demand in this case for Photo JPEG is basically esoteric at this point. Nothing gained especially when they have Final Cut.

Thanks to everyone for their responses-- and finally, special thanks to Andy Neil. You really addressed the Photo JPEG concern and confirmed a straight export from Final Cut will work.

And I agree, the 44.1 kHz is pretty dumb. I think this whole thing is because they have a Media 100 system and are reluctant to really make a move to FCP.

Reply

Answer 9

Feb 1, 2009 11:37 AM in response to tbrookskazoo

when converting 720x480 to 720x486, I'm pretty sure you need to add 4 lines of black at the top and 2 at the bottom (or vice versa) otherwise you'll reverse the field order. It's been a while, so my memory may be wrong.

Reply