DV Questions

[wildboar]

Hi.. I hope somebody could give me the responses to these DV related questions that I couldn't find in any of the forum:

1. How can I know that my AVI file is of which type: Type 1 and Type 2? I connected simply my video camera to PC using Pinnacle studio and also Roxio and I got very big sized AVI files... but I never knew they are saved as which type? The 4CC code for these AVI files transferred using diff. programs (pinnacle and roxio for instance) are same or different?

[goc]

you can use gspot software
look here (http://gspot.headbands.com/gspot25features.html ) it's great

[wildboar]

I have Gspot but it doesn't tell the type of AVI file, if it's TYPE 1 or TYPE 2. Moreover for the file that i transferred using ROXIO, it gives blank in 4CC code, while for the file transferred using Pinnacle it gives dvsd as the 4CC code... what does it mean?

[bb]

Originally posted by wildboar
I have Gspot but it doesn't tell the type of AVI file, if it's TYPE 1 or TYPE 2.
A simple way to verify the DV type is to open the AVI file in VirtualDub. If it's type-1, VirtualDub will report a warning because of the way audio is stored in type-1. If it's type-2, the warning will not appear.

Originally posted by wildboar
Moreover for the file that i transferred using ROXIO, it gives blank in 4CC code, while for the file transferred using Pinnacle it gives dvsd as the 4CC code... what does it mean?
The 4CC is an information in the AVI header telling a program which codec to use to decode the video. The code should not be blank. For DV there are mainly two options, DVSD (Microsoft and others) and CDVC (Canopus). There's a fourcc changer program available at Doom9's download page.

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[wildboar]

In other words, 4CC code doesn't have the impact over the quality of the AVI file.. that's what I have understood after reading different responses.. fine !! I have also read your DV to DVD guide.. I haven't understood one thing related to codecs while encoding a video by using encoders like TMPgenc.. Do i need to install any DV codec before using encoders? eg. panasonic, mainconcept or anyother.... I am not very clear about it even after reading the forums.. As you wrote there are two 4CC codes DVSD and CDVC... I think every comp is equipped with microsoft codecs to decode DVSD.. For canopus, to decode CDVC, I don't know.. if they are already one the PC or one needs to install them.. If they need to downloaded and installed, from where can i find them???? tried to look different codec software sections but couldn't find.. Am i missing some information? Thanks for clarifying this !!

[bb]

The fourcc code itself does not have an impact on the DV quality - the DV codec does, though. But the differences are not huge. There's a sticky thread about DV decoder differences, if you're interested.

There are basically two ways to decode DV (if the video application doesn't have integrated DV support): VfW (= Video for Windows) or DS (= DirectShow). Windows OSs have the Microsoft DV DS filter on board by default, which means that you can decode DV through DirectShow without installing a DV codec, provided that your video application is prepared for DirectShow (VirtualDub is not). VfW applications need a VfW DV codec installed, e.g. MainConcept, Canopus, etc., or you may frameserve through AviSynth by using the "DirectShowSource" command.

If you want to feed an encoder with DV data, there are four possible scenarios:
1. the encoder is capable of decoding DV (none of the big encoders is)
2. the encoder reads AVI through the windows API using a VfW codec (all of the big encoders do that)
3. the encoder decodes DV through DirectShow (e.g. TMPGEnc can do this directly, see "Environmental Options" > "VFAPI" for the DS vs. VfW priority settings)
4. the encoder gets fed by a frameserver, preferrably AviSynth. AviSynth can decode DV via VfW (AviSource) or via DS (DirectShowSource). The decoder receives raw (decoded) video data.

Regarding the download location of DV codecs I ask you to read the sticky threads ;)

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[wildboar]

It was too hard to understand it all :-(( And I am not too sure what I have understood is right or not?
Here I resume:
- DV is decoded using different decoders (MS codecs that uses DirectShow, Other Codecs (canopus, mainconcept etc) that uses VFW)

- I have to use TMPGenc to encode the videos. I know it encodes my video if I follow your DV to DVD guide BUT I don't know at all which codecs are being used?

the encoder decodes DV through DirectShow (e.g. TMPGEnc can do this directly, see "Environmental Options" > "VFAPI" for the DS vs. VfW priority settings)

I have checked that DS has more priority(-1) over VFW codecs(-2) in my TMPGenc.. Does it mean that my TMPGenc will always use MS directshow codecs and can't use VFW codecs, if I am able to download and install then any day ! Actually I read DV codecs guide too but couldn't figure out where these DV codecs are available?? are they provided by Digital Cameras? Also How could I know that which codecs are already installed on my computer..
Thanks!!

[wildboar]

3. the encoder decodes DV through DirectShow (e.g. TMPGEnc can do this directly, see "Environmental Options" > "VFAPI" for the DS vs. VfW priority settings)


Is it possible to change the priority in TMPGenc from DS to VFW so that I use canopus codecs to decode DV instead of MS while encoding using TMPGEnc?


Regarding the download location of DV codecs I ask you to read the sticky threads ;)


I have found all the codecs. I was looking at the wrong sections all the time :-(

Thanks for your information.. Now i have got almost all the things :-)

[bb]

Originally posted by wildboar
Is it possible to change the priority in TMPGenc from DS to VFW so that I use canopus codecs to decode DV instead of MS while encoding using TMPGEnc?[...]
Should be possible by setting the "DirectShow Multimedia File Reader" to a lower priority than the "AVI2(OpenDML) File Reader". This should be the default by the way. Maybe you have to increase the "AVI VFW compatibility Reader" so that it is higher than DirectShow, too (don't know for sure).

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