Is DV-AVI after editing really lossless??? Guess NOT!!!

[HAGGARD]

Hi there...

Can someone explain (or try to) that even after editing an DV-AVI video and after writing back to camera or export to DV-AVI still is lossless???
I did some testing myself with different software (Adobe Premiere, Studio8) and found out that this is not the case!!!

What I did :
Captured DV-AVI via firewire to computer with both Premiere and Studio8...
Edited it also in both Premiere and Studio8 (some titles over video)...
Exported to DV-AVI...
Edited it Again, Exported to DV-AVI again...
Edited it Again, Exported to DV-AVI again...
Edited it Again, Exported to DV-AVI again...

Noticed that video had become more and more garbeld/distorted!!!
Worked with DIGITAL duplicates, right??? Why is quality of video getting more worse everytime I export it??? DV-AVI shouldn't be lossless, right???
DV-AVI should be allready compressed in the videocamera, right???
But editing software has to do some RE-Encoding, so quality is deteriorating!!!

Did another test:
Captured DV-AVI via firewire to computer with both Premiere and Studio8...
Edited it also in both Premiere and Studio8 (some titles over video)...
Exported to Huffyuv... (thank god I have HD-space-allot... HUGE FILE!!!)
Edited it Again, Exported to Huffyuv again...
Edited it Again, Exported to Huffyuv again...
Edited it Again, Exported to Huffyuv again...

Videoquality isn't deteriorating anymore!!!

Can someone still convince me that DV-AVI isn't lossless???

'HAG

p.s. I want to get the most out of my video, that's why i'm testing, testing testing....

[txpharoah]

Nothing is "lossless".
Some just are not as noticeable as others (ala Huffyuv).
Your DV-AVI codec is just more noticeable.

[HAGGARD]

Thanks txpharoah!

I Guess I just fooled myself in believing that DV-AVI isn't lossless, although often mentioned in these forums!!!
So the quality of the edited video is depending on the decoder in the editing software!!!
I'll stick with huffyuv then, since it's compressed AND LOSSLESS!!!

Thanks again...!

'HAG

[disturbed1]

If you add effects to a part of the video, that part needs to be re-encoded. Each time you re-encode you lose quality.

If you decide to put a scrolling title across 5 minutes of film, that 5 minutes needs to be re-encoded. Color correct the whole film? The whole film gets re-encoded.

I've upgraded to Avid DVXpress in the last 3 days, and haven't noticed multi generational edit degradation compared to when I used Vegas. Could be the DV codec, or the editting program it self.

[HAGGARD]

Aha,

Now I have another question in this case...

As disturbed1 mentioned, only edited video is re-encoded (eg. a transition in this case in Studio8). I've noticed that Studio8 first renders all effects (transitions/wipes/etc.) in the auxiliary directory and then pastes all videoparts in the correct order back together (so only effects have to be re-encoded). This sometimes give problems... I've noticed that sometimes after a effect, the audio has got a glitch (audio is gone very short)...
I've done allot of video editing with studio 8 and never before had this problem...
Is this a decoder problem or is Studio 8 not putting them together correctly???

'HAG

[disturbed1]

Try to edit your video seperate from the audio, then add the audio back when you export.

This should get rid of the glitches. Just don't trim or cut without the audio on the timeline

[HAGGARD]

distubed1,

This is not the problem.... During editing, audio is fine...
Just after exporting to DV-AVI, audio has glitches...

strange, ej?!?

'HAG

[EricB]

DV isn't lossless but it does solve the problem of making a high quality backup of your original. Passing the video back and forth between the camera and computer is just a file transfer so original quality is maintained. For most applications I have found, this is more important than having a huge "lossless" file that I have no way to store back to tape.

[Gazorgan]

In Premeire, when you export you encode. The whole point of projects is you can make an edit change and re-export a new file, not the old one.

You can be lossless by no re-encoding the video. To do that all the clips ahve to be the same codec/resolution. The downside is transitions have to be rendered.

[BJ_M]

If you add effects to a part of the video, that part needs to be re-encoded. Each time you re-encode you lose quality.

If you decide to put a scrolling title across 5 minutes of film, that 5 minutes needs to be re-encoded. Color correct the whole film? The whole film gets re-encoded.

I've upgraded to Avid DVXpress in the last 3 days, and haven't noticed multi generational edit degradation compared to when I used Vegas. Could be the DV codec, or the editting program it self.

sofo's codec is wildly considered to be far better than the one Avid uses (microsoft) , it has been tested to 10 generations - avid's you can get about 3 ..

this has been reported by several mag's and on several forums .

i tested it myself also and you can do the same test -- generate smpte color bars and do a 45degree shift in color or something so that you should in 8 generations come back to the original .. vegas will be dead on and avids not .. canapus codec is also quite good -- main concept dv codec is better than ms's butr not as good as the other 2 above ..

[HAGGARD]

disturbed1,

I have found the problem with the glitches in audio with Studio8...
I had footage recorded with 2 camera... one with SP and the other with LP.
So AudioSamplingrate is different... (SP=48kHz, LP=32kHz)

Changed samplingrate from 32kHz to 48kHz and that solved the glitching problem...

Thanks though for your advice.

'HAG

[Zabbo]

What company is SOFO ?

[Dasio]

SONIC FOUNDRY, maker of Vegas software, one of the best.
I've just picked -up Vegas4+DVD of e-bay ($260.00). I LOVE IT!!!!

[Oliver]

I just started the process of converting my home videos on VHS to SVCD (am a total newbie), and am glad to have learned about the generation loss when editing video. I'm using the Canopus ADVC-50 to capture with and plan on using Adobe Premiere to edit. I want my SVCDs of my home videos to be the best quality possible, so would like to avoid losing quality every time I make an edit to one of my DV-AVI files. Just want to be sure I got this straight, I should convert my DV-AVI file to a Huffyuv encoded AVI file, and edit that? How do I perform such a conversion? Does Premiere offer such a capability? TIA.

[BJ_M]

SONIC FOUNDRY, maker of Vegas software, one of the best.
I've just picked -up Vegas4+DVD of e-bay ($260.00). I LOVE IT!!!!

vegas 4.0c update is now on the sonic foundry website as of today ..


you should install it .. you can install over the top of what you bought - no problem ussually ..

[disturbed1]

@BJ_M-
Avid use MS? Maybe when you view it, but it encodes using it's own codec, the Avid DV codec, they used Canpus as their model. It's rendered in QT. Compatible with DV50 and DVCPro. Not a directshow, nor VFW codec.

It's only on loan for now until I decide. I like the UI, and the effects edit, but I don't think I'll switch from Vegas Considering I already own DVD A, and Sound Forge, wouldn't make too much sense at this point. Doesn't seem to do much more than what I can already do. The UI just looks better to me, the plugins are what makes it. It'd about break me just for the app alone.

Thanks for the heads up on Vegas C. I was there earlier and didn't see it, must of just been posted.

HAGGARD-
That could've been the problem Glad you got it fixed.

[vhelp]

@ haggard..

I'm gonna bust some nuts here..

>> I Guess I just fooled myself in believing that DV-AVI isn't
>> lossless, although often mentioned in these forums!!!

No.., I think you got it mixed up or so..

Assuming your are talking about HOME FOOTAGE via lens, then..
DV is lossless**(1) in the sense that you:
* take your DV CAM's footage,
* firewire as DV to your harddrive,
* then send it back to your DV CAM (w/out any editing) via firewire

Yes, the above is lossless.


**(1) Ok, here's the skinny on lossless DV.
It's NOT lossless, rather LOSSY. Ok, let me explain.. imagin that
you are taking some home footage and recording it to miniDV tapes.
I'm not sure exactly WHEN the DV Conversion/Compression process takes
place, but it could be in either one of these instances:
A) - At the point where your home footage is being recorded onto your
miniDV tape OR,
B) - When you transfer it to your hd via firewire route.
The reason why I mentioned B) is because in my expeirence, I used the
S-Video of my Canon ZR-10 and captured from this connection, and in my
eyes, couldn't see any noticable DV compression anywhere's in sight. It
looked like I had captured the source straight from my source, which
happens to be satellite. That is why I call my CAM, a mini TIVO..
because I record to miniDV tapes and later, CAPTURE it via analog capture
card OR my ADVC-100 (how ironic) - - eather way, both analog capture
methods produce the same quality level.. so I have multiple choices in
my video processes.

So, as you can see, AFTER your DV CAM converts your footage to DV, which
is LOSSY at that stage, when you finally transfer it to your hardrive, it
is lossless in that sense, digitaly speaking. And, when you re-transfer
it back to your DV cam, you are in effect, performing a lossless transfer.
BUT, if you perform any editing that requires some re-encodes in any
section of the DV source ie, in vdub or premier or whatever DV type editor,
you will have some re-encoding in those poritons, if not the whole DV
footage. And, when you transfer it back to your DV cam (after the re-encode
or re-convert from your DV editor app) you are STILL performing a lossless
transfer. ..remember ?? during your DV editing stage ie, in premier, you
did some titleing or fades or whatever.., it's there, that you are re-conerting
(or encoding/compressing) the DV source. But, when you transfer it back to
your CAM, you are performing a digital (lossless) transfer (not conversion)
When you are in, say, premier, you are in a sense, in a DV state. As you
perform any editing, your DV ins (on the fly) performing the DV compression
if it needs it.

So, lets say that you transfered your DV footage into vdub. Once inside
vdub, you are say, in DV land. You can cut/merge your DV w/ other DV source
materails (no re-encoding needed here) and then export it back out to miniDV
tapes, and all in lossless form. Hmmm..., but what if you want to take some
HUFFY .avi files and merge them together with your DV source ?? Well, what
happens is this.. your HUFFY source is converted into DV format. So, the
conversion had taken it's place and finished inside vdub's time-line. Now,
you want to export the whole finished .AVI file back out to your DV CAM..
again, is lossless format, because all the conversion was done on the fly
during or inside vdub's time-line. Pretty weird, ah ??

So, the only time your are encoding (to DV format) is whenever your bring in
a source (any) inside your DV app, ie's premier or vdub, your app will perform
the conversion/compression on the fly inside that time-line w/out your ever
realizing it. But, when you transfer or export it (any app) it will STILL be
in lossless format. So, now lets bust some more nuts.. NOW, you've exported
your edited source to your CAM (onto miniDV tapes) NOW, later on, maybe a
week or so, you get an idea, and decide to export (or transfer) the footage
from your miniDV tapes BACK (LOL) to your harddrive for yet, even MORE editing
bla, bla bla. WOW. I just cracked a screw here. Because, if I'm not mistaken,
when I export out to my harddrive what is on my miniDV tapes, I'm gonna be
doing it lossless'ly .. .. wow.. double stumped!!

Now, here is a side note, that you all need to realize and pay attention to
and factor into YOUR equation.. Depending on your setup, and which DV codec
you have installed, you COULD very well be re-converting when your export
your footage back to your harddrive.. IF you do it on another persons PC that
has a different DV codec installed..
So, watch out for that, else you'll fool youself into thinking that I'm
wrong in what I'm saying here.. that DV is NOT lossless (but, when it really
is lossless) You need to know that some DV codec will vary slightly in it's
conversion algorithem.. ie, mainconcept vs. canopus vs. pannasonic etc.

I hope you understood all that.
-vhelp

[BJ_M]

@BJ_M-
Avid use MS? Maybe when you view it, but it encodes using it's own codec, the Avid DV codec, they used Canpus as their model. It's rendered in QT. Compatible with DV50 and DVCPro. Not a directshow, nor VFW codec.

It's only on loan for now until I decide. I like the UI, and the effects edit, but I don't think I'll switch from Vegas :wink: Considering I already own DVD A, and Sound Forge, wouldn't make too much sense at this point. Doesn't seem to do much more than what I can already do. The UI just looks better to me, the plugins are what makes it. It'd about break me just for the app alone.

Thanks for the heads up on Vegas C. I was there earlier and didn't see it, must of just been posted.

HAGGARD-
:agree: That could've been the problem :D Glad you got it fixed.

as for plug-ins for vegas -- lots coming very soon .. boris for vegas will be out in very short time and some more really really nice ones ... as well with the v-dub plug in all the v-dub plugins are usable (most of them) and satash has some really other nice stuff with his 3d LE pac for vegas ..

including the frame server for vegas now out ..

your right on the avid dv codec , i was thinking of some other app - but the render test on dv codecs i mentioned (using avid) is correct .. big plus also of vegas over avid is the preview fuctions ... well many other things also..

[troyvcd1]

When I use mediastudio 6.5 and add titles I create the titles and the "links" to these titles within mediastudio. This way when you create your new avis you are not actually reencoding the titles everytime. I am not sure how they call these "links" to your edited video. These links also apply to pictures and everything else you put into your edited video. It point out clearly that you want to create your video this way so your added stuff does not get reencoded with every new avi. I am sure that adobe premiere probably this.

[HAGGARD]

Oliver,

Just want to be sure I got this straight, I should convert my DV-AVI file to a Huffyuv encoded AVI file, and edit that? How do I perform such a conversion? Does Premiere offer such a capability? TIA.

Just to make something straight:
The footage recorded on a DV tape (either Digital8, DV or MiniDV) is allready recorded with the DV25 standard!!! So compression (4:2:0) is allready done in the camera!!!
If you transfer this footage to computer via firewire then DV artifacts are allready in it, even when transfered via SVHS to capturecard (which gives even more artifacts like noise (its analog, remember!)). If you edit this footage just 1 time and then export this footage back to camera or author for (S)VCD/DVD, there shouldn't be any noticable artifacts!!! But if you edit this footage again and again, artifact become more visible.
I mentioned huffyuv because I use more tools to edit video (eg. Studio8 for capture/edit, Premiere to make scrollers). Also huffyuv makes HUGE files (30 minutes in my case took 28GBytes!!!!!!) and makes Premiere slow (because the amount of data it has to transfer).

'HAG