DV captures don't look good on PC - not an interlacing problem

[sync]

I'm dubbing TV from a high quality satellite source. When I play back from the camcorder to the TV the quality is excellent. After capturing through firewire the material looks washed out. The material is telecined. After doing inverse telecine it plays back more smoothly, but it still looks washed out.

vhelp, who has the same camera (Canon ZR10), posted that he has the same problem. He solved it by doing an analog capture from the DV. There has to be an explanation for why this is happening with a firewire capture. The only thing I can think of is the DV codec (I'm using Panasonic codec).

Isn't a firewire capture a simple transfer of bits. Is it possible that Canon implemented this in a faulty manner?

[waldok]

I've been doing this myself with a Canon MV400i and didn't notice pictures being "washed out". I used Scenalyser live with Microsoft DV codec.
Did you check your camcorder settings, in case there are specific luminance settings for DV out (pretty unlikely but you never know).
(I suppose you played your recorded material on the TV through analog output ?)
What software are you using for capturing through firewire ? Are there any "capture-time" luminance settings in your software ?

Finally, did you try with another codec ?

Let me know some more details about this, so I'll try to help.

Waldok
:cool:

[sync]

I couldn't find any luminance settings in either the camcorder or the capture software.

I'm using Premiere for capture. Under video settings it says that the compressor is Micorsoft DV.

I just tried Scenalyser with the Canopus codec. When I load the AVI into Virtual Dub it says that "Stream 1 has an invalid sample rate". I got the same error when I tried Type2 DV. I don't even see any setting within Scenalyser for the frame rate.

At this point I don't know how to try any other codec.

When I create or load a project in Premiere I get an unusaul error message: "Premiere was unable to connect to the native Microsoft DV support on this machine. 1394 playback is not setup correctly. Playback performance will be impacted."

[SiliconSoul]

its the ZR10. i had that camera. it does weird things and its not consistent. Ill never buy another canon ZR series camera AGAIN!

[OvERaCiD23]

Does it still look the same after exporting it back to tape? Maybe it's just displaying wrong on your PC monitor. I have a ZR20 and have never experienced in regular DV footage or TV captures. BTW, I use the MS DV codec; I see no need to use other codecs.

[sync]

I used the Panasonic codec because there isn't an MS DV codec on my system.

I found that if I capture, edit and print back to tape then it looks good when played on TV. If I capture, edit, encode, author as SVCD then it looks washed out.

It's not because it's an SVCD either. I've seen several samples that look quite good.

[SiliconSoul]

now thats a problem in the encoding processes. i think you have a filter or something that is changing the source during encoding. the SVCD should look the same (beside the point that its lower bitrate and different size). But im not sure exactly how that is happening... i use Canopus Procoder to encode to VCD, SVCD, DVD. has lots of options and nice filters and encode great without filters also.

[vhelp]

Hi all.

@ Sync and SiliconSoul (and others)

It IS the Canon ZR-10. Something to do w/ the DV processing and
what-nots.

* The is nothing wrong in the encoding process either
* Its not the SW codecs used either - tried them all
* Its not the Type 1/2 settings either
* It's not the firewire or OHIC either
* ben there and done it all.

S-Video and Analog Capture route..
Now, through and after many trial and error's, I've concluded that
if you use the Analog capture card route instead, the color washout
is non-existant. Colors will be as they were. Weather you exported
to AVI, and back to Tape, and then re-captured it, you would get
no color washout.

Bottom line..
The ZR-10 is plauged by a system bug or something.
I NOW have added the Sony DCR-TRV22 to my list of CAMS,
and using the exact same steps in ALL my previous and present
attempts, the TRV22 passes the test w/ flying colors. No color
washout as in the ZR-10.

@ sync..

If you want to continue w/ your process. I would suggest to use the
S-Video ports and capture from there. Your source will be as they
were before then passed through your CAM's mechanism. So, continue
as you were - - S-Video it !!

Sony DCR-TRV22.. Interlace and Progressive..
I have found that there is an undocumented feature of this unit.
It does have the capability to shoot in progressive mode. That is,
it's "final" output is progressive and NOT Interlaced - - there is
no trace of it. It's a bit rough, and certainly NOT true progressive,
but heck, if you want to rid yourselves of home-footage de-interlacing,
then the Sony DCR-TRV22 is the cam to get, and under $800.

@ sync..
Good luck thus far, guy.

Later on.
-vhelp

[Xesdeeni]

Try using the MainConcept (http://www.mainconcept.com/downloads.shtml) codec instead.

Xesdeeni

[SomeJoe]

Your problem is the way the Canon camcorder (and many other, but not all Japanese camcorders) handle analog inputs and outputs.

US NTSC analog signals have a phenomenon known as "setup". To understand it, a brief review:

Analog NTSC video signals are typically measured in IRE values. 0 IRE corresponds to a zero voltage signal, and 100 IRE corresponds to a maximum voltage signal.

Due to historical reasons, US NTSC analog signals reference 7.5 IRE as "black". 0 IRE is "blacker than black". The presense of a 7.5 IRE reference signal is commonly referred to as "setup".

All US NTSC analog equipment is supposed to follow this convention, and when it outputs a picture, 7.5 IRE is used for black.

However, many Japanese camcorders do not follow this standard. They use 0 IRE as their black level.

It is important to remember that "setup" is an analog-only phenomenon. Setup and IRE values do not exist in the digital domain.

CCIR-601-conforming digital video (which DV is) has its own standards for luminance representation: Black is supposed to be 16, white is supposed to be 235.

Analog->digital and digital->analog conversion is where the problems come in. The device doing the conversion needs to know whether to add or remove setup to/from the analog signal during conversion. For instance, in a properly operating US NTSC DV camcorder or DV deck, if it was capturing a US NTSC analog signal, it would remove the setup from the analog input, and then write the proper values to tape as DV. a 7.5 IRE signal on the analog input would get recorded as a luminance value 16 pixel, which is black. Similarly, when that DV camcorder or DV deck was playing back that DV, setup would be added to the analog outputs. So the pixel value of 16 outputs a 7.5 IRE signal.

Your Canon ZR10 ignores setup on both analog inputs and outputs. So lets see what happens:

You record from your cable/sat box, and the camcorder doesn't remove setup from the analog inputs. A 7.5 IRE signal coming from your cable/sat box is recorded as a pixel value of 32 on the tape (which is a dark gray, not black). It makes this error because it believes that 0 IRE should be black (16). 7.5 IRE is lighter than that, so the pixel is recorded as a 32.

If you now capture to the computer using 1394, you get a direct digital copy. Things that are supposed to be black now show up as dark gray on the computer -- the picture looks "washed out". This washed-out look will be carried over into the MPEG encoders and onto your DVD or SVCD.

On the other hand, if you capture via analog, the camcorder does not add setup to its analog outputs. The pixel value of 32 on the tape is converted to 7.5 IRE, which your capture card believes is black, not dark gray. Thus the pixel becomes 16 in the DV file on the computer, like its supposed to be, and the picture is restored to what it is supposed to look like.

So -- the root of the problem is that your camcorder follows Japanese NTSC standards vice US NTSC standards for analog signals.

Work-around: if you capture to the camcorder from analog inputs, you MUST send that signal through the analog outputs to fix the error.

Better solution: Get a different camcorder that properly removes setup on analog inputs and adds it to analog outputs. This way, the digital data on the tape is correct (16=black), and you can now capture via 1394 with no brightness shift.

Interestingly, another effect from these camcorders is that if you actually shoot footage with them, you MUST capture that footage via 1394 for it to look correct. When shooting footage, blacks are recorded on tape correctly, at black=16. If you capture via analog, where no setup is added, the picture will look too dark on the computer and DVD/SVCD.

[SiliconSoul]

what camera's do the analog to digital conversion and back right? im looking at saving for a camera in the Canon GL2 range. 2k-3k. YES IM TIRED of the crappy lower end camera and im NUTS MAN! :D
;)

[sync]

SomeJoe,

Thanks for the very interesting post.

Like SiliconSoul, I'm interested in knowing how to find a camera that does it right.

[sync]

Get a different camcorder that properly removes setup on analog inputs and adds it to analog outputs.
Does anyone know how to find out which cameras function according to SomeJoe's suggestion?

[SiliconSoul]

Well we could do it the hard way by using a CC and buying and returning camera till we get one that works the way we want it to!
:D