Is this a stupid question? m2t -> avi

Noggle wrote on 9/2/2008, 5:35 PM
Hi All,

I'm still fairly new to HDV editing (from a Canon HV30) and I always do as much reading as possible before jumping in so as to avoid problems. Often the reading takes less time than trying to sort out the problems! These are things I think I have worked out:

1. Although Vegas Pro 8 edits HDV m2t files, it seems that it would prefer not to and is often sluggish and clunky. Editing avi files is still the way to go. T or F?

2. The Cineform Neo programs capture the HDV files from tape and converts the m2t into an avi wrapper. T or F?

3. This is because it's much better (for many various reasons) to edit avi files (e.g. lower degradation) rather than m2t files. T or F?

4. Therefore, if we can't afford the Neo program(s) and are willing to put in the effort, after Vegas Pro 8 captures an HDV tape as m2t files it would profit us all to render these to an avi wrapper and then edit the avis. T or F?

As I said, this might be a really dumb question, but I want to work in the best manner (which may end up being to fork out some $ for the Neo HDV program).

Thanks.

Regards,
Noggle

Comments

johnmeyer wrote on 9/2/2008, 6:07 PM
1. Although Vegas Pro 8 edits HDV m2t files, it seems that it would prefer not to and is often sluggish and clunky. Editing avi files is still the way to go. T or F?

Both. Editing m2t works very well for simple project and where you don't have really complicated compositing. Also, if you capture your HDV in Vegas (and don't use, for example HDV Split), the performance should be pretty reasonable.

That said, if you convert to Cineform AVI, except for the time it takes to do the conversion and the 60 GB vs. 13 GB of space Cineform takes, everything else (performance and quality) is better.

2. The Cineform Neo programs capture the HDV files from tape and converts the m2t into an avi wrapper. T or F?

True, although a little misleading the way you stated it. Probably clearer if you say that it converts the m2t into a Cineform AVI file. All AVI files are "wrappers" for some sort of codec. However, when you state it the way you did, it could possibly be misinterpreted as meaning that the m2t file still exists within the AVI file. Instead, it has been completely transcoded into a new format where every frame is independent of all other frames, just like DV, MJPEG, HuffYUV, uncompressed, and others, but unlike MPGE-2, m2t, etc.

3. This is because it's much better (for many various reasons) to edit avi files (e.g. lower degradation) rather than m2t files. T or F?

It's better to edit DV or Cineform AVI files. However, editing DivX or other similar AVI files will be just as fraught with problems as m2t or MPEG-2. So AVI, since it IS a wrapper, can contain formats that use interframe compression and are therefore a bitch to edit.

4. Therefore, if we can't afford the Neo program(s) and are willing to put in the effort, after Vegas Pro 8 captures an HDV tape as m2t files it would profit us all to render these to an avi wrapper and then edit the avis. T or F?

True. See my answer above.
Chienworks wrote on 9/2/2008, 6:10 PM
I'm just guessing here, but i think you're off on your thinking. The reason that MPEG and similar files are sluggish in Vegas is because they use compression across groups of frames. Most of the frames are incomplete and rely on data from previous or following frames so these are much slower to preview and work with.

The reason that typical files contained in AVI wrappers are faster to edit is because these file types typically use discrete frame compression. Each frame is complete on it's own.

So, if i'm more or less correct on those two points, your answers would be:

1) True

2) False. It's not the wrapper that matters, it's the compression used.

3) False. Discrete frame files edit faster. Degradation is completely unrelated. Avoiding degredation is dependent upon the rendering system being able to to copy original data to the new file without rendering, or failing that using higher bitrates so that less data is lost.

4) True, but not in the way you think. It's not the wrapper that matters, it's the underlying file type. SONY's YUV is a good intermediate codec that uses discrete frame compression with very little loss.
johnmeyer wrote on 9/2/2008, 6:22 PM
Although our answers might appear slightly different, Kelly and I are saying exactly the same thing and are in complete agreement.
Chienworks wrote on 9/2/2008, 7:18 PM
Whew. i done guessed good! ;)
Noggle wrote on 9/4/2008, 6:20 PM
Thanks to all who replied. You have all increased my understanding, though it looks as though I still need to some more reading to get an even better understanding. Ta!
Steve Mann wrote on 9/10/2008, 6:54 AM
I've been editing with Vegas for five years and I am still learning something new every day.