Strictly conform to AVI2 specification?

farss wrote on 2/3/2008, 10:43 PM
Anyone understand the implications of not having that box checked in preferences?

Reason I ask is I just gave two 11 minute AVI files to a client. He loaded them into his ULead system and the audio stops around the 4 minute mark and ULead MS says the file is AVI type1 which I have vague memories about having some problems.

Comments

John_Cline wrote on 2/3/2008, 11:25 PM
Bob,

I recently posted the following in response to another thread here on the forum, but it applies to your question, too.

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There is some confusion about this whole AVI Types 1 and 2 and AVI2 thing.

AVI Type-1:
The native DV interleaved stream that is produced and consumed in I/O with a DV device contains DV compressed video and pulse code modulated (PCM) audio data. This single interleaved stream can be stored in an AVI file as "ivas" stream (for interleaved video/audio stream). Microsoft refers to this format as a type-1 DV AVI file.

Because the type-1 format stores data as a single AVI stream, type-1 DV AVI files are not compatible with VfW. DirectShow, however, easily handles type-1 data streams by routing the streams to a DV Splitter filter that produces a DV-encoded video stream and one or more PCM audio streams for playback or subsequent processing.

AVI Type-2:
Interleaved DV data can also be split into a single video stream and one to four audio streams within an AVI file. Microsoft refers to this format of storing DV data as type-2. This format has the advantage of being backward compatible with VfW, because it contains a standard video "vids" stream and at least one standard audio "auds" stream.

Note that the type-2 file format requires a small amount of additional processing to split and multiplex the DV stream during the functions of capture and transmit to IEEE 1394 DV devices.

The confusion exists because there is also "AVI2" which was developed by Matrox in order to break the 2-gig barrier. This is completely different than AVI Type-1 ot Type-2 files. Vegas is a VFW application which, by default, writes Type-2 AVI2 files. This is what Vegas is talking about when it says "Strictly Conform to AVI2 specification." Vegas always write an AVI Type-2 file. If his ULead system is reading the file as a Type-1 file, then there is something wrong with his system.

John
farss wrote on 2/4/2008, 12:06 AM
Thanks John.

Interesting. The files that he gave me out of ULead must be Type-1 as Vegas created audio proxies for 2x stereo tracks. His system does say it's using a DV Type 1 codec.

For certain this guy has problems with people other than me. The version of ULead MS he's using is years out of date, he had it setup for 32K audio and his camera was set to record 12/32K, one great big mess. What we've agreed to do is record the material to tape, that at least is a given format.

Bob.
JohnnyRoy wrote on 2/4/2008, 5:44 AM
> What we've agreed to do is record the material to tape, that at least is a given format.

Actually it's not unless you also agree how to write it back. Many moons ago before I used Vegas I did a project with a friend in Premiere. I wrote it back to tape thinking I had a safe copy I could use later. Years later when I went to re-edit it in Vegas I found that it had been recorded to tape by Premiere using 32K audio on 4 tracks and Vegas can only see the video. No audio!

So writing to tape is no guarantee of compatibility.

~jr