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Old 08-05-2007, 03:12 PM   #1
diner19GV
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Default What is the difference between AV12 and Canopus DV and Microsoft DV ?

Hi

in procoder when out putting as an AVI I can select between AV12 and Canopus DV and Microsoft DV and I am wondering what is the difference between them ?

is the quality any different ?

The output looks much the same to me but I'd like to know the manual does not explain any real differences between them or if one is better or more compatible than another.


Does anyone know the answer to one of life's little puzzles ;)


Thanks from d
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Old 08-05-2007, 04:47 PM   #2
SRsupport
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This has been answered a couple of times.
Here is a copy of Brandon his post:

Okay, time for the long explanation...

In the beginning, there was Video for Windows (VfW) and the data-wrapping file format AVI.
Video for Windows AVIs are often referred to as "AVI 1.0" AVI files.
Video for Windows AVIs were originally limited to 1 GB maximum size, but the size was later extended to 2 GB.

FAT (FAT16) was the filesystem used at the time.
FAT has 2GB maximum file size, and a 2GB maximum volume size (in NT you could format a FAT volume from 2GB up to 4GB with 64KB clusters, which can be problematic).

Circa Windows 95, ActiveMovie was introduced. ActiveMovie still used AVI. ActiveMovie later morphed into DirectShow. DirectShow is often referred to as "AVI 2.0"
At the same time, FAT32 was introduced.
FAT32 has a 4GB maximum file size, and a 127GB (Win9x) or 2TB (WinME, practical limit due to partition table) maximum volume size.

Meanwhile, there's NTFS, used by various versions in NT, 2000, and XP.
NTFS has a current practical limit file size and volume size of about 32TB.

Matrox and some others proposed an extension to AVI 1.0 called OpenDML, which was later implemented in AVI 2.0. This extension allowed AVIs to be larger than 2GB.

Canopus had its own extension of AVI 1.0, used in its applications, called Reference AVIs. This allowed a single AVI up to 4 GB, and multiple "reference" data files, allowing the total content to be over 4 GB.

So, a particular AVI file can be one of four types - Video for Windows aka "AVI 1.0" or DirectShow aka "AVI 2.0"
It's worth noting here that it is possible to create a "partially backward-compatible AVI 2.0" file, but the ability for VfW to access the AVI content is limited to the first 1, 2 or 4GB of the AVI, depending on the method the program uses to access it.

And the filesystem the AVI is stored on can be one of three types - FAT (FAT16), FAT32, or NTFS

This gives us this for maximum AVI sizes by AVI type and filesystem.
  • Video for Windows (AVI 1.0)
    • FAT (FAT16): 4 GB (2 GB practical, safe)
    • FAT32: 4 GB (2 GB practical, safe)
    • NTFS: 4 GB (2 GB practical, safe)
  • Canopus Reference AVI
    • FAT (FAT16): 4 GB (2 GB practical, safe)
    • FAT32: slightly over 2 TB (127 GB, practical, safe)
    • NTFS: slightly over 2 TB (2 TB, practical, safe)
  • DirectShow (AVI 2.0)
    • FAT (FAT16): 4 GB (2 GB practical, safe)
    • FAT32: 2 TB (127 GB practical, safe)
    • NTFS: 32 TB (2 TB practical, safe)
And then comes the further confusion. When DV came onto the scene, Microsoft defined two "types" of DV AVI files. This was because AVIs traditionally held two streams - the video stream and the audio stream. That's why you see a lot of interleaving references for AVIs - that determines how the audio and video data are arranged in the file so they can be accessed in sync. The DV format datastream, however, includes both audio and video multiplexed together.

Thus, two methods for storing DV data in AVIs (aka DV AVIs) were defined. The logic is there, but the naming makes it confusing, as it is opposite of the AVI 1.0/2.0 referencing.

"Type 1 DV AVIs" are DirectShow AVIs with the DV datastream in the vids stream. There is no decoded audio track.

"Type 2 DV AVIs" are Video for Windows AVIs with the DV datastream in the vids stream and a copy of the decoded audio in the auds stream. The copy of the audio allows traditional Video for Windows applications to decode the audio properly for playback and manipulation. However, this can lead to problems, as described further.

Audio troubles with Type 2 DV AVIs...
Because the audio exists both in the DV datastream in the vids stream of the AVI, and in the auds stream of the AVI, any changes to the audio need to be made in both the DV datastream and the audio in the auds stream. This would ensure that the audio is correct regardless of whether the audio is being decoded from the DV datastream stored in the vids stream, or simply being pulled from the audio in the auds stream.

However, programs that are not "DV AVI aware" would read the AVI as a normal AVI, assume the audio only exists in the auds stream, and therefore modify the audio in the auds stream, without modifying the audio in the DV datastream. This leads to discrepancy between the audio tracks. Playback of the AVI from an application that pulls audio from the auds stream (traditional AVI playback) could play entirely different audio from a DV AVI aware application that decode both audio and video from the DV datastream.
This is why in "the old days" sometimes you'd get a Type 1 DV AVI that played back with "wrong" audio in one application, but "right" audio in another - a bit of an "audio split-personality" problem.

3-hour limit of Canopus Reference AVIs
Since the AVI 1.0 maximum safe AVI file size is 2 GB, and the audio is being stored in Canopus Reference AVIs, there is approximately a 3 hour limit, assuming 48 kHz 16-bit stereo audio.

Okay, that's the end of today's lesson. Those of you whose heads have not exploded, please do the rest of the class a favor and scoop up the excess brain matter of your fallen classmates so nobody slips and falls.

Hope that helps explain things. __________________
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Old 08-05-2007, 10:31 PM   #3
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To add to SR's post from Brandon,
Canopus DV is a better codec, but during multi-generation use. Microsoft DV and Canopus DV are visually the same when you first capture your footage. Multiple re-renders on the same file will show you that Canopus DV is a better codec.

Nowadays I just capture everything in Microsoft DV, because these files are universal and even work under OSX without problems (QuickTime handles them fine). I use Type2 Microsoft DV, and I don't have the 2GB/4GB limit per file on an NTFS file system or over an SMB (Samba network).
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Old 08-06-2007, 08:37 AM   #4
diner19GV
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Quote:
Originally Posted by STORMDAVE View Post
To add to SR's post from Brandon,
Canopus DV is a better codec, but during multi-generation use. Microsoft DV and Canopus DV are visually the same when you first capture your footage. Multiple re-renders on the same file will show you that Canopus DV is a better codec.

Nowadays I just capture everything in Microsoft DV, because these files are universal and even work under OSX without problems (QuickTime handles them fine). I use Type2 Microsoft DV, and I don't have the 2GB/4GB limit per file on an NTFS file system or over an SMB (Samba network).


Thanks <Stormdave> your answer makes sense and with audio it's the Microsoft wav Soundforge likes best so I'm not surprised the Microsoft DV is more universal but the canopus is slightly better (to be safe I think I will go with the Microsoft DV)

I have no idea why <SRsupport> put that explanation how AVI's came into being and the old file size limits of FAT16 FAT32 as I only want to know if I out put as avi if in those choices the results are much the same or one is better or one is more compatible I'm trying to avoid finished project headaches !!

> AV12 and Canopus DV and Microsoft DV and I am wondering what is the difference between them ?


WMP doesn't play the Canopus DV but it's ok in the timeline, I want to crop some 4.3 avi and out put to 16.9 avi to use in the timeline with some 16.9 avi files for a multicam project and I don't want to find out later I selected the wrong one.

It's funny in books they have an appendix with any refence material listed for further research but with PC program manuals that is very rare and it's assumed you already know all that stuff ............. maybe that's why there is an internet !!!

Thanks again , d
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Old 08-07-2007, 07:34 AM   #5
GrassValley_BH
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Canopus DV and Microsoft DV are both codecs.
Codecs generate the data that goes into an AVI.
AVIs are "labeled" with a codec identifier (Four-CC code). This code tells the applicaiton reading the AVI what codec to use to work with the data stored within.
Both codecs generate DV data.

Now, the AVI container - it can be VfW-type or DirectShow-type. Either can contain DV data, and neither care whether the DV data stored within was created using the Microsoft DV codec or the Canopus DV codec.

To make a long and confusing story short...
Both EDIUS and ProCoder use the Canopus DV codec for encoding and decoding DV AVIs, so unless you're generating files for use with older pre-EDIUS Canopus products, you're best off creating Microsoft DV (DirectShow-type) AVI files.

That way any DV-aware application will be able to use the file.
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Old 08-07-2007, 07:39 AM   #6
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I like the longer version better. :)
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