I was always thinking that generation loss did not occur by dv-avi but I was clearly wrong, look it up by google, there are hundreds of websites that explain the generation loss by dv-avi, and I have read many, many websites about it.

When you capture video from a dv tape, make cuts to it and send it back to the tape, there is NO generation loss, but on the moment you want to have a title or effect in the video, than you must render it, on that moment you are using a codec, and that is a generation loss, so there is no way you can have no generation loss when you want to use effects, or even colour correct the video.

Here are some websites forums describing that:

http://www.videohelp.com/forum/viewtopic.php?p=525854

http://www.globalmediapro.com/av/messages/176795.html

Google has hundreds of links about this subject.


A creativecow.com website has a in-depth article about this and tells that you have always generation loss, and if you decide to go “uncompressed” you have generation loss because you encode the dv file to another format, when you are going back to tape from uncompressed video, you have another generation loss!
So the only way NOT too have any loss is not to include anything that was not part of the original video, and everyone is including something!
Such as titles or colour correction.

So watch this! And read about this, iam not very technical, so please go to google because this can harm your project very bad (I have seen it by a short film of mine, I was exporting to DV-AVI between after effects and premiere, ten times or so, and the video has lost quality)

But are there people here who can tell me what is the best way to use premiere and after effects? Because if you export to DV-AVI or UNCOMPRESSED AVI you are having generation loss so how can I get into AE without having to deal with this?

You can import a project, but the project is NOT remembering any transparency, effects, motion effects etc… and I think why: the cannot include that because otherwise you have to render! And you don’t render when you import a premiere file into AE, so there is no generation loss by doing that, but that is also the reason the projects forget all the transparency, effects etc!
Its only remembering the timing of the film, the cuts and the titles (because that are different files, not on the video yet)

So are the people here who have an idea?

It's true.... but the loss is very minimal if you avoid rendering more than once, and use programs with good DV compression algorithms (like FCP, AE, etc).

For instance, if you need to do a lot of transferring back and forth saving it uncompressed would be the best way, that way you're only re-rendering once at the end.

quote:

Originally posted by titaniumdoughnut:

For instance, if you need to do a lot of transferring back and forth saving it uncompressed would be the best way, that way you're only re-rendering once at the end.

I have search for that but not find the answer, do you mean that once you have exported your material to uncompressed avi (generation loss) you can import/export/render/ again and again and again, without generation loss at all?

So that Uncompressed to Uncompressed = no generation loss at all (because it dont use a compression) ?

Because even uncompressed must render and take time to export.

Is this the case?
If so, than you only have 2 times when there is generation loss: by the exporting TO uncompressed avi and by the exporting BACK to dv avi.
This is a lot better than 5 times exporting to dv-avi i think, right?

I don't know about uncompressed AVI for sure. I would use a lossless codec like the Animation codec in QuickTime.

Basically, exporting from DV to lossless video has, as the name implies, no quality loss. The DV artifacts are preserved, and everything stays the same as long as you use the correct pixel sizes/ratios and everything.

Then you can do as many conversions as you want within the lossless codec, without losing a thing. Save a billion times, no loss. The only loss will occure when compressing from lossless back to DV. So there will be one generation's worth of loss.

i don't understand why people use .avi when .mov are more flexible and way better at using for just about everything.

anyway, digital video is only lossless when it uncompressed, and as far as i know only Avid Symphony is the only editing system that can do full uncompressed video.

any other program compresses it when using a codec to write it to the drive.

quote:

Originally posted by RFranco:
anyway, digital video is only lossless when it uncompressed, and as far as i know only Avid Symphony is the only editing system that can do full uncompressed video.

This isn't true, not only can all of Avid's products do Uncompressed 1:1 but so does most professional editing systems out there. (including FCP and Premiere)

You just need to make sure you choose their "uncompressed" codec.

A little bit of trivia however, I've heard that all uncompressed codecs are not entirely uncompressed because of a patent issue. Someone patented "uncompressed video" so what is done is it actually compresses one meaningless pixel or some other wierd thing to get around the patent issue without actually compressing the image at all.

-Chris
Studentfilms.com

oh really? any Composer i've worked on won't let you do 1:1, like it won't even let you chatge the settings (it's always greyed out). i thought it was either symphony or an upgraded Composer that could do it.

and i thought FCP couldn't do it because you'd need a RAID setup to keep all the video and FCP can't really capture to different RAID drives like Avid can? or does it?

what an interesting development for me.

oh wait i just realized, are we talking about uncompressed miniDV or any uncompressed video, like DigiBETA, HD, etc?

and how come people still send tapes out to be mastered if the editing software can do it uncompressed on it's own?

i would digitize BetaSP at 2:1 ratio on the Composer, on an 8 drive RAID0 setup, and i would take up 2-3 drives. the only time i ever got it on 1 drive is if i used the decomposed clips.

This message has been edited. Last edited by: RFranco,

quote:

Originally posted by titaniumdoughnut:

Basically, exporting from DV to lossless video has, as the name implies, no quality loss.

Are you sure?
Because this explains why its not:

"Since uncompressed 4:2:2 systems use their own codec (compression-decompression) format, the DV clip needs to be converted to the uncompressed system's native format by either transcoding it (best quality) or capturing it from your DV deck in real-time either digitally (SDI) or by analog inputs (component, Y/C, composite). By decompressing the DV codec to an uncompressed codec, you're losing 1/2 generation of quality. Additionally, going back to DV from an uncompressed codec also looses 1/2 generation of quality. The entire process looses 1 full generation of quality loss"

Full article can be found on:
http://www.creativecow.net/show.php?page=/articles/solo...ure_cards/index.html

So that sound not very good either (i think.)

But what about this:

I have a dv-avi movie, render it a couple of times and finely export it the last time and burn it on a cd-rom, this is my back-up copy, the final video file of my movie, but now a filmfestival is saying that there Must be 10 seconds black video before the movie starts and another 10 seconds after the movie...

Then i must import the DV-AVI file to premiere (the final movie file ^) add the black video to it and export it again as DV-AVI.

What do you do?
one festival is asking 5 sec. of black before the movie, another one is asking 10, one person whants letterbox and another whats true 16:9
So how can i deal whit this?

I cannot make 10 copys because i dont know how many seconds the whant the movie have before it begins, (i also render with Magic Bullet so that is taking 2 days!)

So how do you deal whit making a adjustment to your video?
I always did it simple: exported the final video file to dv-avi before applying the "magic bullet" to it, after that i import that file and export it as letterbox and when i want more black video before of after it: i just import the final video file and export it whit the adjustment.

But this is having a HUGE generation loss.

So there is nothing more i can do about this workflow for the files i already have, but for the next project what can i do, can i make 1 final video file and import/export that file whit adjustments etc?

PS: Even this website (Well, not the website, the big boss behind the other side of the screen from the website ) has all kinds of special demands:
Example: "have at least a minute of pre-roll at the beginning of the
tape so that I can digitize the film"

And the is asking for a special codec too, almost every festival/website etc are asking for other specifications so everytime i must import the final video file, make a adjustment (in this case the 1 minute black video) and export it again, i have huge generation losses!

(funny detail is dat Chris is saying:
"The video signal must be clean and without any generation
loss"

Funny because you must edit the video file (for the 1 minute specification) and than export it again, how do you mean no generation loss?

(i understand why there must be 1 minute of black video before it, but i dont anderstand that it may not have generation loss )

This message has been edited. Last edited by: Jerry,

Well - it really depends on the drive setup. There's a setting, filter based on resolution, that will let you capture at 1:1 if your drives can handle it.

I know for sure Media Composer Adrenaline and Avid Xpress Pro with the Mojo can capture it.

Also, uncompressed used to be a paid for option so if you're working on a much older version of Avid it might not be there.

As for FCP - I'm no FCP expert but I think you need an SDI capture board to capture Uncompressed but this is when capturing Digibeta via SDI.

-Chris
Studentfilms.com

That's balony - by capturing DV footage via SDI into a Symphony at 1:1 and then sending it back out there is no generation loss.

Besides, if you're onlining on a Symphony, why the heck would you output your master to DV. Send it to Digibeta - with again - no generation loss.

-Chris
Studentfilms.com

If this "generation loss" was noticable, people would care and some company would do something about it.

But it isn't, so no one cares, and everyone's happy.

quote:

Originally posted by Studentfilms.com:
That's balony - by capturing DV footage via SDI into a Symphony at 1:1 and then sending it back out there is no generation loss.

Besides, if you're onlining on a Symphony, why the heck would you output your master to DV. Send it to Digibeta - with again - no generation loss.

-Chris
Studentfilms.com

What is balony???
You were replying to your own message, or too mine or too someone else?

I just capture my footage whit adobe premiere (firewire) DV-AVI, only after that i have captured i dont know what to do: export it as some kind of uncompressed file or not

Sorry - I was saying "that's balony" to the creative cow article.

If you cut it at the DV res captured via firewire, outputting it via firewire back to tape shouldn't be a problem.

Theoretically there is no generation loss when outputting to tape. Where there could be a generation loss is when rendering FX within the app.

There is no generation loss when rendering to uncompressed within the app - only when rendering using the DV codec. Avid can render to different codecs within the app when rendering - I'm not sure about other apps. I know FCP can't mix resolutions.

-Chris
Studentfilms.com

"If you cut it at the DV res captured via firewire, outputting it via firewire back to tape shouldn't be a problem.

Theoretically there is no generation loss when outputting to tape. Where there could be a generation loss is when rendering FX within the app"

That is what the creative cow article is saying,
that there is zero generation loss when just cutting the video and export it back whitout adding things to the video such as effects and when you use FX there can be generation loss.

So, you are saying the same

Execpt that you are saying that there is no generation loss when rendering to uncompressed, and that sounds very nice to me, so i hope you are right and not the creative cow article!

Jerry

1 quistion (to everyone)

If you import video whit firewire to Premiere, there cut the video whitout applying effects etc, then you open After Effects and import the premiere file (so the video is not exported, only the premiere file which is a reference to the videofiles) and there you apply all your effects etc.
If your movie is all done, you export/render it whit After Effects to a uncompressed video file.

Now you have only export the video once, from dv to uncompressed, so there is minimal (or nothing at all) generation loss, and when you ever wanted to change the movie or add something, you can import the uncompressed file and render it again to the uncompressed file whitout generation loss.

Is this a good way to handle future projects?

If so, that i have one more quistion:

Uncompressed files are way to heavy to send to a filmfestival or so, those files dont play normal on most computers i think (it does not play good on my pc)
so if i have the uncompressed file, to what format must i render the file to view the movie?
Because uncompressed is just way to heavy, but when you do import/export the file as another file, you loose your "uncompressed" quility.

So? what about this?

That's a pretty good way to handle it, yeah. Unfortunately you need to compress back to DV for pretty much any festival.

quote:

Originally posted by titaniumdoughnut:
That's a pretty good way to handle it, yeah. Unfortunately you need to compress back to DV for pretty much any festival.

Yes, but how do you handle this?

Carefully.

Just export it to DV through QuickTime or whatever app you're using.

I personally have never had any problems with generation loss in DV, so I'm not real worried about all of this.

I am not very worried,
but it would be a waste if i have a video file (microsoft dv-avi) and import this file to output another copy of it in letterbox format, and another copy for 1 minute of black video before it etc...



So i want 1 good video file which i can edit and export again whitout loss.
and if i wanted to recut my film, then i would be a waste if i got many generation losses,

so iam a little bit worried about which videofile i must use as back-up.

(The master file)


And besides this, i have also started this topic to warn other users about this, if you dont have problems whit it, then that is only good.