Editing raw footage

Jeff Donald · May 2nd, 2003, 02:45 PM

Don,

Was the source of the color bars the same for both tests?

Simon Orange · May 2nd, 2003, 03:00 PM

Just done some peliminary tests on my laptop

1 - SMPTE bars generated internally in premiere 6.5 (using an uncompressed project). Saved as uncompressed 24 bit .bmp

2 -imported this .bmp into one frame project in AFX 5.5.
each movie re-imported into AFX project and exported as uncompressed 24 bit .bmp

Exported as AVI using each DV codec.

using mainconcept 2.1 demo - poor

microsoft DV v6.5.1.900 - poor

canapus v3.0 demo - best but not perfect

notes:
1.don't know where the canapus codec came from
2.main concept codec was ran with fastest mode de-selected (assume this is highest quality ?)

I know I am giving subjective analysis at this stage. Will do the test tommorow on a winXP machine all service packed up and present proper results and post all relevant before/after/project files. I will also try to get hold of SF codec (does anyone have it ?)

si

Don Donatello · May 2nd, 2003, 04:28 PM

the SMPTE color bars i used are generated in Vegas .. they are digital generated media .. i only used 5 sec color bars ..and rendered out using standard NTSC DV template ..i did both good/best quality and the results were same.

again i used Vegas 4 for both SOFO and microsoft codec .. i have direct X 9 (updated 2 weeks ago from microsofts win2K site) ) .. operating system doesn't matter it is NOT going to affect results ( but it was win2K ) but you are correct that versions of directX will be different. direct X 9 is current ..

my point for the TEST was you don't need to do 10 X re-rendering
.. 1 render will show you results ... it is easier to see results if you

have a vectorscope/waveform .. but RGB #'s will also tell you something especiall with BIG #'s difference like MS codec.

.. i rank SOFO , canopus , Avid , QT6, mainconcepts dv codec ALL excellent and would not avoid any of em ... but i do find i can say that one should aviod the microsoft dv codec which is the default on ALL PC 's. it is not going to show you the correct colors when you color correct on a NTSC/computer monitor ..

have not tried any matrox or pinnacle products

Simon Orange · May 2nd, 2003, 04:29 PM

Ok......it seems that the DV codec in Vegas is coded into the application and doesn't make itself available to other apps.

....mmm

will sleep on it

Don Donatello · May 2nd, 2003, 04:36 PM

"The issue is with FX and transitions that need rendering. It is more than feasable to do bits of FX work uncompressed using either uncompressed TIFs or AVI, then you will get the best quality possible"

remember if you have a DV clip .. now you want to make it a tga/tiff/png/jpeg or uncompressed avi/QT, mpeg or what ever .. you need a DV codec to uncompress the clip - so if your version of premiere defaults to microsoft DV codec then that is what it is going to use to uncompress the DV clip so it be changed into a PNG/tiff/tga, uncompresseed avi/qt

Simon Orange · May 2nd, 2003, 06:11 PM

Don,

Totally agree about the uncompressing (although I haven't seen any tests results for this) and Premiere would of course use MS codec for this by default - although my gut feeling is that the decompress between codecs would be quite similar (famous last words !). Might even test that later.

I am more concerned about the quality of the MS codec. I have just compared my initial test results with yours and I notice that your MS results are way off compared to mine (using aftereffects). My MS results are about half-percent off perfect..not a great deal different than the MC ones. Yours are miles away ! Does this mean that Vegas handles the codec in a different way ?

In addition - just because Vegas can read and write its own codec perfectly it doesn't mean that it can read other codecs well...it seems to make a more of a mess with the MS codec than AFX...In fact referring back to your original point about the decompress - who is to say SF is decoding the original Canon (sony ?) hardware codec correctly in capture mode ? Doesn't matter if you are copying back to the camera but it might if you were working uncompressed......In fact I assume you pulled the video back into Vegas to test RGB values - the error might have crept in here - not at the MS compress - this would have ramifications on footage imported from other applications.

This isn't a 'my codec is better than yours' debate - we all know the MS codec is sh*t - I just trying to evaluate how sh*t. And why is the SF one so much better ? Is it time to give MC a try ?

I hasten to add that these thoughts are just that....thoughts ! And I am assuming that a codecs ability to compress colour bars is the sole indicator of its quality(which it obviously aint) - but I have spent years working with D1 and digibeta and never seen a 50x dub look anything like the original (even with D1 - which you would at first assume was just a digital clone)

Have tested mainconcept/canopus/MS and might have a look at vegas. Will post results tommorow.

simon

Garret Ambrosio · May 2nd, 2003, 07:34 PM

Have any of you use AlamDv? I don't have scientific data regarding this, but it refuses to use the MS DV codec. According to their website (ww.csbdigital.com or alamdv.com) the MS codec is a low quality codec and therefore they recommend using the Matrox, Mainconcept or Canopus DV codecs when running their software. Just a quick tidbit.

Don Donatello · May 3rd, 2003, 12:55 AM

" My MS results are about half-percent off perfect..not a great deal different than the MC ones. Yours are miles away "

you might have something on perhaps a software tunes their render engine to the default codec ! could be ?

your results are Vaild for your computer /sofware and that is what counts ... how did the the pluges read out using MS with AE .... were you able to view them on vectorscope/waveform ?

now on my computer the MS DV codec shows more into shadows and midrange , seems to holds highlights and that is explained in my test of seeing it LIFT the blacks ( 3 pluges) and it brings down the 235 whites to 218 ...

how does your Premiere handles the MS codec in rendering ?.. put your digital generated BARS in Premiere's TL .. can you get a RGB' read out on em in Premiere ? .. then render them out in Premiere and put them back in premiere or AE and read them against the GENERATED bars #'s ... your results could/will be different then mine and that is what you should go by ... let us know how Premiere MS dv codec did on rendering - did the #'s match AE?

i'll try out rendering with Combustion and Commotion using the MS dv codec this weekend - just to see if each handles the same codec different ... i know Commotion is QT native..

Rob Lohman · May 3rd, 2003, 04:07 AM

I've done some research on the Microsoft DV Codec in the past
and the quality/version can be a tricky thing. It has happened
a couple of times that a NEWER version of the DV Codec actually
made things worse. So it might be that the DV Codec in DX9
that Don is using might be newer but in more worse in quality
than an older codec that Simon might be using... If you want
to know what version you are you using do the following:

1. go to your <winroot>\system32 directory (make sure you can see system files)

2. find the file QDV.DLL and right-click on it and choose properties.

3. Go to the version tab and you'll see the version on top

I seem to be running version 6.3.1.881 on my Windows 2000
Professional Service Pack 3 system. According to DXDIAG I am
running DirectX 8.1.

Simon Orange · May 3rd, 2003, 09:13 AM

ok....

test results at:

http://www.hyperstar.demon.co.uk/codec_test.zip

Don,

started to repeat tests just using premiere but results looked the same as AFX (check the zip file). If you could post the files that you generated in vegas (or anything you make in combustion/commotion) I would be interested to see them. Seems like there is something a bit weird going on using the ms codec.

Rob,

As far as I can tell I am running the same version of the MS codec as Don.

Garret,

I assume that AlamDV can't use the MSDV codec because it needs a VFW codec and the MSDV is directshow only. The MC codec is VFW also. Check out:

http://www.microsoft.com/hwdev/tech/...dcap/dvavi.asp

to All,

one last thing: this is from the mainconcept FAQ

Does the MainConcept DV Codec do lossless compression? My understanding is there are two parts to DV encoding. Can it do the entropy encoding only (lossless) and skip the DCT compression (lossless)? In other words, I could edit/compress an infinite number of times without lossing any data, or I could record DV and then recompress it in a different format and won’t get any additional loss from the DV Codec.

There is a loss of Quality when you create new frames. New frames are created when you use effects (FX) or transitions on a clip. These new frames must be calculated and produced. In this case you have a loss of quality. The visible loss is shown by the cycle ratio. For example, a ratio of 5 means, that you can recompress a DV clip 5 times without a visible loss. Our cycle ratio is higher than the one of the Microsoft DV codec. A pure copy from a DV clip, e.g. from one DV camcorder to your hard disk and back to another DV camcorder will cause no loss.

simon

Don Donatello · May 3rd, 2003, 11:46 AM

down loaded your samples

the premiere BAR export avi was BLACK , canopus avi had errors on my system ...

i found all STills color bars to be pretty much right on and they all had very close the same RGB's numbers ..

however all the avi 's do not come close to your stills ??

all the avi's have about the same readings to each other (AVI).. very small difference on waveform/vectorscope ..however again they do not come close to the STILLS ??

using the uncompressed still (color bars are correct)

the 100% white on the stills are 235 ..on the avi's around 218 ?

still RED 180 16 16 the avi's 173 29 29

still GREEN 16 180 16 the avi's 28 171 27

still BLUE 16 16 180 the avi's 29 30 174

now what i notice is that all your avi's are pretty much matching my rendered MSdv bars .....

are you getting RGB's readout that are showing the AVI 's have the same #'s as the original COLOR bars ? they should match up with the STILLS if the source was the same bars ..

try taking the uncompressed color bar.tiff and render that out as a AVI - now do a RGB read out comparing the 2 ... they should match

i find the readings on the STills to be correct for SMPTE color bars.
all the readings on the AVI's i find not to be correct ..
i assume the source of color bars was the same for stills and avi?

my version of the QDV 6.5.1.900
directX 9a 4.09.0000.901
win2K 5.0.2195 service 3 build 2195
msdv.sys 5.3.0.900

Simon Orange · May 3rd, 2003, 12:02 PM

how odd...

the stills were taken from the AVIs........not the other way round...

basically:

1. started with 1 frame of uncompressed colour bars
2. loaded in AFX
3. exported 3 movies (3 different compression codecs)
4. loaded the 3 'new DV compressed movies' and exported a still from each.

Just to spell it out again....

the stills are taken from the movies - not the other way round. If you are saying that the AVIs are of a lower quality than the stills that come from it then there is something else going on. In premiere and AFX the AVIs measure (RGB values) the same as the stills that are exported from them.

The canopus DV codec is obviously some kind of proprietry codec...it was on my system (don't know why) .best just ignore it !..

to comment further I need to know in detail your method for measuring/creating/viewing etc.....

simon

Don Donatello · May 3rd, 2003, 01:36 PM

we are getting the same readings on the STILLS ..

not sure why why are you converting the avi's into stills ??
seems if final output is AVI's then the readings should be from AVI's ?...

are you getting the same RGB's readings on your stills and AVI's ?

i was using Vegas for RGB readings on the AVI's and the stills ..Last night i read the RGB's in Combustion. i just did it again this AM using Commotion and they all have same read out's .. i'm reading the AVI's not converting to them to stills ..

looking at your steps
1) i find your uncompressed still to be CORRECT
2) ...
3) i find all your avi's do NOT match the uncompressed still
4) i find all the stills do match the uncompressed still

in your PDF you are listing my AVI's RGB #'s and your Stills RGB #'s .. again it is your avi's that i find to be off.. maybe others don't ??

?? you are on XP ..i'm on win2K ..perhaps there's something different ?? perhaps others could RGB read the AVI's and stills to see if the difference is in the OS ??

--------------
i load the AVI clips & stills into vegas/commotion/combusting
i then sample RED,GREEN,BLUE bars with eye dropper for the read out ... for waveform/vectorscope i use Vegas which matches external waveform/vectorscope.

on the AVI's i sent you .. Vegas produces digital generated bars, they do not exist as a still or avi ... i then rendered out 5 frame avi using SOFO codec ..then rendered out a 5 frame avi using the MSdv codec ... you should see that if you RGB read both AVI's the SOFO ( Vegas) avi will match your uncompressed still and the msDV codec will pretty much match your AVI's ( not the stills from your avi's) ....

Simon Orange · May 3rd, 2003, 06:31 PM

PART 1 OF 2 POSTS (phew...!)

Don, thanks for your patience.....

As I mentioned to you earlier, I have put your files at:

http://www.hyperstar.demon.co.uk/don.zip

but to answer your questions first:

> we are getting the same readings on the STILLS ..

yes

> not sure why why are you converting the avi's into stills ??
> seems if final output is AVI's then the readings should be
> from AVI's ?...

yes and no ...trying to eliminate the application (vegas/premiere/afx) from the equation..it is the application doing a decompress on the file when it opens, which I think is the root of the problems. I have enclosed the AVIs also for comparison.

>are you getting the same RGB's readings on your stills and AVI's ?

YES...absolutely...for both AFX and Premiere. Additionally rendering bars in AFX 'OR' Premiere gives exactly the same quality of image as the final stills (otherwise the framegrab export would be increasing quality) I am willing to guess I would get the same results from combustion, shake or whatever else but not if VEGAS was installed (a clue here ?).

>i was using Vegas for RGB readings on the AVI's and the
>stills ..Last night i read the RGB's in Combustion. i just did it
>again this AM using Commotion and they all have same read
>out's .. i'm reading the AVI's not converting to them to stills ..
>
>looking at your steps
>1) i find your uncompressed still to be CORRECT
>2) ...
>3) i find all your avi's do NOT match the uncompressed still
>4) i find all the stills do match the uncompressed still

3 and 4 gives the clue to the issue i think.

>in your PDF you are listing my AVI's RGB #'s and your Stills RGB
>#'s .. again it is your avi's that i find to be off.. maybe others
>don't ??

Because on my machines they are EXACTLY the same.

>?? you are on XP ..i'm on win2K ..perhaps there's something
>different ?? perhaps others could RGB read the AVI's and stills
>to see if the difference is in the OS ??

One of my machines is XP one machine Win2k

>--------------
>i load the AVI clips & stills into vegas/commotion/combusting
>i then sample RED,GREEN,BLUE bars with eye dropper for
>the read out ... for waveform/vectorscope i use Vegas which
>matches external waveform/vectorscope.
>
>on the AVI's i sent you .. Vegas produces digital generated bars
>they do not exist as a still or avi ... i then rendered out 5 frame
>avi using SOFO codec ..then rendered out a 5 frame avi using
>the MSdv codec ... you should see that if you RGB read both
>AVI's the SOFO ( Vegas) avi will match your uncompressed still
>and the msDV codec will pretty much match your AVI's ( not the
>stills from your avi's) ....

Makes perfect sense..thanks, with one proviso. This assumes that original bars match mine...(no reason not to but it would be nice to be sure..your 11.5 looks off to me - and the ones the premiere creates aren't correct)

STAND BY FOR PART ...the conclusion

Simon Orange · May 3rd, 2003, 08:18 PM

PART 2 OF 2........THE CONCLUSION (nearly)

Playing Don's avi (x2) this is what I see on my machines....

Don's MS codec file isn't great - lots of bleed between colours..poor colour accuracy etc etc but Don's Vegas codec file is worse !! the pluge at the bottom right...almost all are black (certainly on my system - check out: http://www.greatdv.com/video/smptebars3.htm and compare).

Similarly, my mainconcept and MS codec AVIs don't look right on Don's machine.

If someone else can open Don's avis (http://www.hyperstar.demon.co.uk/don.zip) and double check my findings. Playing the files in media player will be best. Probably best if you are using DX9 DV codec or mainconcept one.

Actually I was gonna finish this post with more conclusions about SOFO codec, how it decodes the MS/MC codec incorrectly..and visa versa......how it takes over the system and forces other apps to use it........how it might upset your ability to use premiere correctly if you had vegas installed - but as I was writing this I thought I best not be lazy and double test my conclusions in Vegas (the app, not the city). I booted up a third (win2k machine), installed vegas 4.0b demo...and attempted to play Don's clips in media player confident that the vegas codec would look fine......it didn't. Opened vegas (not used it before) and imported both don's clips....still looked wrong....mmmmmmm. Reboot (you never know! )...still no good.

After this last minute double check on my theory I am now thinking that there is an issue with either Don's machine or mine. I suggest that somebody else tries to play Don's avi's, check that the various shades of grey (pluge - bottom right) show correctly - or at least near.

If the vegas codec avi doesn't look right on other peoples machine then I think the problem is with Don's machine...if they do the problem is with my machines - OR - the issue is with the compatiblity between codecs and it didn't just didn't catch me out when I installed vegas (!?!).

Incidentially, I have no doubt that the SOFO codec is the better of the codecs tested, but checking through the SF site forums suggest that the canopus one might have advantages also. I know all of this seems a little pedantic but the quality loss seen by Don using the MS codec and me viewing the Vegas codec is huge.....and would mean all rendered footage would be greatly degraded and files made on one machine could not be used safely on another.

si

May 2nd, 2003, 02:45 PM	#16
Jeff Donald Warden Join Date: Mar 2002 Location: Clearwater, FL Posts: 8,287	Don, Was the source of the color bars the same for both tests? __________________ Jeff Donald Carpe Diem Search DVinfo.net for quick answers \| Where to Buy? From the best in the business: DVinfo.net sponsors

May 2nd, 2003, 07:34 PM	#22
Garret Ambrosio Major Player Join Date: Mar 2003 Location: Vallejo, CA Posts: 263	Have any of you use AlamDv? I don't have scientific data regarding this, but it refuses to use the MS DV codec. According to their website (ww.csbdigital.com or alamdv.com) the MS codec is a low quality codec and therefore they recommend using the Matrox, Mainconcept or Canopus DV codecs when running their software. Just a quick tidbit. __________________ "USA Today has come out with a new survey - apparently, three out of every four people make up 75% of the population." -David Letterman

May 3rd, 2003, 04:07 AM	#24
Rob Lohman RED Code Chef Join Date: Oct 2001 Location: Holland Posts: 12,514	I've done some research on the Microsoft DV Codec in the past and the quality/version can be a tricky thing. It has happened a couple of times that a NEWER version of the DV Codec actually made things worse. So it might be that the DV Codec in DX9 that Don is using might be newer but in more worse in quality than an older codec that Simon might be using... If you want to know what version you are you using do the following: 1. go to your <winroot>\system32 directory (make sure you can see system files) 2. find the file QDV.DLL and right-click on it and choose properties. 3. Go to the version tab and you'll see the version on top I seem to be running version 6.3.1.881 on my Windows 2000 Professional Service Pack 3 system. According to DXDIAG I am running DirectX 8.1. __________________ Rob Lohman, visuar@iname.com DV Info Wrangler & RED Code Chef Join the DV Challenge \| Lady X Search DVinfo.net for quick answers \| Buy from the best: DVinfo.net sponsors

May 2nd, 2003, 03:00 PM	#17
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	Just done some peliminary tests on my laptop 1 - SMPTE bars generated internally in premiere 6.5 (using an uncompressed project). Saved as uncompressed 24 bit .bmp 2 -imported this .bmp into one frame project in AFX 5.5. each movie re-imported into AFX project and exported as uncompressed 24 bit .bmp Exported as AVI using each DV codec. using mainconcept 2.1 demo - poor microsoft DV v6.5.1.900 - poor canapus v3.0 demo - best but not perfect notes: 1.don't know where the canapus codec came from 2.main concept codec was ran with fastest mode de-selected (assume this is highest quality ?) I know I am giving subjective analysis at this stage. Will do the test tommorow on a winXP machine all service packed up and present proper results and post all relevant before/after/project files. I will also try to get hold of SF codec (does anyone have it ?) si

May 2nd, 2003, 04:28 PM	#18
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	the SMPTE color bars i used are generated in Vegas .. they are digital generated media .. i only used 5 sec color bars ..and rendered out using standard NTSC DV template ..i did both good/best quality and the results were same. again i used Vegas 4 for both SOFO and microsoft codec .. i have direct X 9 (updated 2 weeks ago from microsofts win2K site) ) .. operating system doesn't matter it is NOT going to affect results ( but it was win2K ) but you are correct that versions of directX will be different. direct X 9 is current .. my point for the TEST was you don't need to do 10 X re-rendering .. 1 render will show you results ... it is easier to see results if you have a vectorscope/waveform .. but RGB #'s will also tell you something especiall with BIG #'s difference like MS codec. .. i rank SOFO , canopus , Avid , QT6, mainconcepts dv codec ALL excellent and would not avoid any of em ... but i do find i can say that one should aviod the microsoft dv codec which is the default on ALL PC 's. it is not going to show you the correct colors when you color correct on a NTSC/computer monitor .. have not tried any matrox or pinnacle products

May 2nd, 2003, 04:29 PM	#19
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	Ok......it seems that the DV codec in Vegas is coded into the application and doesn't make itself available to other apps. ....mmm will sleep on it

May 2nd, 2003, 04:36 PM	#20
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	"The issue is with FX and transitions that need rendering. It is more than feasable to do bits of FX work uncompressed using either uncompressed TIFs or AVI, then you will get the best quality possible" remember if you have a DV clip .. now you want to make it a tga/tiff/png/jpeg or uncompressed avi/QT, mpeg or what ever .. you need a DV codec to uncompress the clip - so if your version of premiere defaults to microsoft DV codec then that is what it is going to use to uncompress the DV clip so it be changed into a PNG/tiff/tga, uncompresseed avi/qt

May 2nd, 2003, 06:11 PM	#21
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	Don, Totally agree about the uncompressing (although I haven't seen any tests results for this) and Premiere would of course use MS codec for this by default - although my gut feeling is that the decompress between codecs would be quite similar (famous last words !). Might even test that later. I am more concerned about the quality of the MS codec. I have just compared my initial test results with yours and I notice that your MS results are way off compared to mine (using aftereffects). My MS results are about half-percent off perfect..not a great deal different than the MC ones. Yours are miles away ! Does this mean that Vegas handles the codec in a different way ? In addition - just because Vegas can read and write its own codec perfectly it doesn't mean that it can read other codecs well...it seems to make a more of a mess with the MS codec than AFX...In fact referring back to your original point about the decompress - who is to say SF is decoding the original Canon (sony ?) hardware codec correctly in capture mode ? Doesn't matter if you are copying back to the camera but it might if you were working uncompressed......In fact I assume you pulled the video back into Vegas to test RGB values - the error might have crept in here - not at the MS compress - this would have ramifications on footage imported from other applications. This isn't a 'my codec is better than yours' debate - we all know the MS codec is sht - I just trying to evaluate how sht. And why is the SF one so much better ? Is it time to give MC a try ? I hasten to add that these thoughts are just that....thoughts ! And I am assuming that a codecs ability to compress colour bars is the sole indicator of its quality(which it obviously aint) - but I have spent years working with D1 and digibeta and never seen a 50x dub look anything like the original (even with D1 - which you would at first assume was just a digital clone) Have tested mainconcept/canopus/MS and might have a look at vegas. Will post results tommorow. simon

May 3rd, 2003, 12:55 AM	#23
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	" My MS results are about half-percent off perfect..not a great deal different than the MC ones. Yours are miles away " you might have something on perhaps a software tunes their render engine to the default codec ! could be ? your results are Vaild for your computer /sofware and that is what counts ... how did the the pluges read out using MS with AE .... were you able to view them on vectorscope/waveform ? now on my computer the MS DV codec shows more into shadows and midrange , seems to holds highlights and that is explained in my test of seeing it LIFT the blacks ( 3 pluges) and it brings down the 235 whites to 218 ... how does your Premiere handles the MS codec in rendering ?.. put your digital generated BARS in Premiere's TL .. can you get a RGB' read out on em in Premiere ? .. then render them out in Premiere and put them back in premiere or AE and read them against the GENERATED bars #'s ... your results could/will be different then mine and that is what you should go by ... let us know how Premiere MS dv codec did on rendering - did the #'s match AE? i'll try out rendering with Combustion and Commotion using the MS dv codec this weekend - just to see if each handles the same codec different ... i know Commotion is QT native..

May 3rd, 2003, 09:13 AM	#25
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	ok.... test results at: http://www.hyperstar.demon.co.uk/codec_test.zip Don, started to repeat tests just using premiere but results looked the same as AFX (check the zip file). If you could post the files that you generated in vegas (or anything you make in combustion/commotion) I would be interested to see them. Seems like there is something a bit weird going on using the ms codec. Rob, As far as I can tell I am running the same version of the MS codec as Don. Garret, I assume that AlamDV can't use the MSDV codec because it needs a VFW codec and the MSDV is directshow only. The MC codec is VFW also. Check out: http://www.microsoft.com/hwdev/tech/...dcap/dvavi.asp to All, one last thing: this is from the mainconcept FAQ Does the MainConcept DV Codec do lossless compression? My understanding is there are two parts to DV encoding. Can it do the entropy encoding only (lossless) and skip the DCT compression (lossless)? In other words, I could edit/compress an infinite number of times without lossing any data, or I could record DV and then recompress it in a different format and won’t get any additional loss from the DV Codec. There is a loss of Quality when you create new frames. New frames are created when you use effects (FX) or transitions on a clip. These new frames must be calculated and produced. In this case you have a loss of quality. The visible loss is shown by the cycle ratio. For example, a ratio of 5 means, that you can recompress a DV clip 5 times without a visible loss. Our cycle ratio is higher than the one of the Microsoft DV codec. A pure copy from a DV clip, e.g. from one DV camcorder to your hard disk and back to another DV camcorder will cause no loss. simon

May 3rd, 2003, 11:46 AM	#26
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	down loaded your samples the premiere BAR export avi was BLACK , canopus avi had errors on my system ... i found all STills color bars to be pretty much right on and they all had very close the same RGB's numbers .. however all the avi 's do not come close to your stills ?? all the avi's have about the same readings to each other (AVI).. very small difference on waveform/vectorscope ..however again they do not come close to the STILLS ?? using the uncompressed still (color bars are correct) the 100% white on the stills are 235 ..on the avi's around 218 ? still RED 180 16 16 the avi's 173 29 29 still GREEN 16 180 16 the avi's 28 171 27 still BLUE 16 16 180 the avi's 29 30 174 now what i notice is that all your avi's are pretty much matching my rendered MSdv bars ..... are you getting RGB's readout that are showing the AVI 's have the same #'s as the original COLOR bars ? they should match up with the STILLS if the source was the same bars .. try taking the uncompressed color bar.tiff and render that out as a AVI - now do a RGB read out comparing the 2 ... they should match i find the readings on the STills to be correct for SMPTE color bars. all the readings on the AVI's i find not to be correct .. i assume the source of color bars was the same for stills and avi? my version of the QDV 6.5.1.900 directX 9a 4.09.0000.901 win2K 5.0.2195 service 3 build 2195 msdv.sys 5.3.0.900

May 3rd, 2003, 12:02 PM	#27
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	how odd... the stills were taken from the AVIs........not the other way round... basically: 1. started with 1 frame of uncompressed colour bars 2. loaded in AFX 3. exported 3 movies (3 different compression codecs) 4. loaded the 3 'new DV compressed movies' and exported a still from each. Just to spell it out again.... the stills are taken from the movies - not the other way round. If you are saying that the AVIs are of a lower quality than the stills that come from it then there is something else going on. In premiere and AFX the AVIs measure (RGB values) the same as the stills that are exported from them. The canopus DV codec is obviously some kind of proprietry codec...it was on my system (don't know why) .best just ignore it !.. to comment further I need to know in detail your method for measuring/creating/viewing etc..... simon

May 3rd, 2003, 01:36 PM	#28
Don Donatello Hawaiian Shirt Mogul Join Date: Nov 2001 Location: northern cailfornia Posts: 1,261	we are getting the same readings on the STILLS .. not sure why why are you converting the avi's into stills ?? seems if final output is AVI's then the readings should be from AVI's ?... are you getting the same RGB's readings on your stills and AVI's ? i was using Vegas for RGB readings on the AVI's and the stills ..Last night i read the RGB's in Combustion. i just did it again this AM using Commotion and they all have same read out's .. i'm reading the AVI's not converting to them to stills .. looking at your steps 1) i find your uncompressed still to be CORRECT 2) ... 3) i find all your avi's do NOT match the uncompressed still 4) i find all the stills do match the uncompressed still in your PDF you are listing my AVI's RGB #'s and your Stills RGB #'s .. again it is your avi's that i find to be off.. maybe others don't ?? ?? you are on XP ..i'm on win2K ..perhaps there's something different ?? perhaps others could RGB read the AVI's and stills to see if the difference is in the OS ?? -------------- i load the AVI clips & stills into vegas/commotion/combusting i then sample RED,GREEN,BLUE bars with eye dropper for the read out ... for waveform/vectorscope i use Vegas which matches external waveform/vectorscope. on the AVI's i sent you .. Vegas produces digital generated bars, they do not exist as a still or avi ... i then rendered out 5 frame avi using SOFO codec ..then rendered out a 5 frame avi using the MSdv codec ... you should see that if you RGB read both AVI's the SOFO ( Vegas) avi will match your uncompressed still and the msDV codec will pretty much match your AVI's ( not the stills from your avi's) ....

May 3rd, 2003, 06:31 PM	#29
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	PART 1 OF 2 POSTS (phew...!) Don, thanks for your patience..... As I mentioned to you earlier, I have put your files at: http://www.hyperstar.demon.co.uk/don.zip but to answer your questions first: > we are getting the same readings on the STILLS .. yes > not sure why why are you converting the avi's into stills ?? > seems if final output is AVI's then the readings should be > from AVI's ?... yes and no ...trying to eliminate the application (vegas/premiere/afx) from the equation..it is the application doing a decompress on the file when it opens, which I think is the root of the problems. I have enclosed the AVIs also for comparison. >are you getting the same RGB's readings on your stills and AVI's ? YES...absolutely...for both AFX and Premiere. Additionally rendering bars in AFX 'OR' Premiere gives exactly the same quality of image as the final stills (otherwise the framegrab export would be increasing quality) I am willing to guess I would get the same results from combustion, shake or whatever else but not if VEGAS was installed (a clue here ?). >i was using Vegas for RGB readings on the AVI's and the >stills ..Last night i read the RGB's in Combustion. i just did it >again this AM using Commotion and they all have same read >out's .. i'm reading the AVI's not converting to them to stills .. > >looking at your steps >1) i find your uncompressed still to be CORRECT >2) ... >3) i find all your avi's do NOT match the uncompressed still >4) i find all the stills do match the uncompressed still 3 and 4 gives the clue to the issue i think. >in your PDF you are listing my AVI's RGB #'s and your Stills RGB >#'s .. again it is your avi's that i find to be off.. maybe others >don't ?? Because on my machines they are EXACTLY the same. >?? you are on XP ..i'm on win2K ..perhaps there's something >different ?? perhaps others could RGB read the AVI's and stills >to see if the difference is in the OS ?? One of my machines is XP one machine Win2k >-------------- >i load the AVI clips & stills into vegas/commotion/combusting >i then sample RED,GREEN,BLUE bars with eye dropper for >the read out ... for waveform/vectorscope i use Vegas which >matches external waveform/vectorscope. > >on the AVI's i sent you .. Vegas produces digital generated bars >they do not exist as a still or avi ... i then rendered out 5 frame >avi using SOFO codec ..then rendered out a 5 frame avi using >the MSdv codec ... you should see that if you RGB read both >AVI's the SOFO ( Vegas) avi will match your uncompressed still >and the msDV codec will pretty much match your AVI's ( not the >stills from your avi's) .... Makes perfect sense..thanks, with one proviso. This assumes that original bars match mine...(no reason not to but it would be nice to be sure..your 11.5 looks off to me - and the ones the premiere creates aren't correct) STAND BY FOR PART ...the conclusion

May 3rd, 2003, 08:18 PM	#30
Simon Orange Regular Crew Join Date: Apr 2003 Location: London, UK Posts: 48	PART 2 OF 2........THE CONCLUSION (nearly) Playing Don's avi (x2) this is what I see on my machines.... Don's MS codec file isn't great - lots of bleed between colours..poor colour accuracy etc etc but Don's Vegas codec file is worse !! the pluge at the bottom right...almost all are black (certainly on my system - check out: http://www.greatdv.com/video/smptebars3.htm and compare). Similarly, my mainconcept and MS codec AVIs don't look right on Don's machine. If someone else can open Don's avis (http://www.hyperstar.demon.co.uk/don.zip) and double check my findings. Playing the files in media player will be best. Probably best if you are using DX9 DV codec or mainconcept one. Actually I was gonna finish this post with more conclusions about SOFO codec, how it decodes the MS/MC codec incorrectly..and visa versa......how it takes over the system and forces other apps to use it........how it might upset your ability to use premiere correctly if you had vegas installed - but as I was writing this I thought I best not be lazy and double test my conclusions in Vegas (the app, not the city). I booted up a third (win2k machine), installed vegas 4.0b demo...and attempted to play Don's clips in media player confident that the vegas codec would look fine......it didn't. Opened vegas (not used it before) and imported both don's clips....still looked wrong....mmmmmmm. Reboot (you never know! )...still no good. After this last minute double check on my theory I am now thinking that there is an issue with either Don's machine or mine. I suggest that somebody else tries to play Don's avi's, check that the various shades of grey (pluge - bottom right) show correctly - or at least near. If the vegas codec avi doesn't look right on other peoples machine then I think the problem is with Don's machine...if they do the problem is with my machines - OR - the issue is with the compatiblity between codecs and it didn't just didn't catch me out when I installed vegas (!?!). Incidentially, I have no doubt that the SOFO codec is the better of the codecs tested, but checking through the SF site forums suggest that the canopus one might have advantages also. I know all of this seems a little pedantic but the quality loss seen by Don using the MS codec and me viewing the Vegas codec is huge.....and would mean all rendered footage would be greatly degraded and files made on one machine could not be used safely on another. si