Capturing in DV, MPEG or DVD Format?

[babyleon]

This question has been on my mind for a while and I can't locate the answer.

When I capture from my Mini DV Sony camera via Firewire and my "Source" in VS11 showing "Sony DV Device", I have a number of choices in the "Format" box. I usually select "DV" which creates and captures a .avi file of over 14GB for a 1-hour tape.

If I choose either "MPEG" or "DVD" as my capture format, will a resulting DVD that I ultimately produce have a lesser quality than if I start with a .avi file?

[DVDDoug]

You are doing it exactly right! The "captured" AVI/DV file contains the exact, unalterd, DV data from your DV tape.

MPEG-2 (including DVD-compatible MPEG-2) can be "difficult" to edit. I have an MPEG-only analog-capture card, and I had to buy a special-purpose MPEG editor. The less-compressed formats (bigger files) are the easiest to work with. AVI/DV is the most trouble-free format. (The MPEG-4 variations and other highly-compressed formats cause even more trouble than MPEG-2.)

Even with a good MPEG editor, most "real editing" requires the video data to be decoded and re-coded. Since MPEG is lossy compression, you get some additional quality loss with the 2nd encode. (The quality loss is not always noticeable, but it's a potential issue.)

In general, you can get better MPEG-2 encoding if you encode from an AVI/DV file, than if you try to do it on-the-fly during capture. The computer can "take its time", it won't get screwed-up if the prcess is interrupted for multitasking, and you have the option of using two-pass encoding. And, if you need to change the bitrate to make the file fit on a DVD, you can encode a 2nd time without the potential quality loss of re-ecoding the MPEG-2.

With on-the-fly encoding, you do save time by skipping the separate encoding step. And, you save some hard disk space.

[Ken Berry]

While your computer looks up to the job of captuing DVD/mpeg-2 direct from a DV source via firewire, for the sake of completing Doug's useful answer, I would add the following. Many people have found that for reasons either purely of inadequate computer resources or a combination of that and some other quirk(s) of their system, they cannot capture direct to mpeg-2. For whatever reason, the computer cannot process all the incoming data (which comes in at a solid whack) quickly enough. It builds up in what is called the transcode buffer (transcoding the incoming DV data to mpeg-2 on the fly). Waiting for Video Studio to process it. Eventually, sooner more often than later, the buffers fills, so the whole transfer process comes to a halt as the program processes what is in the buffer and empties, so it is ready for more. Unfortunately, this usually means that you have an incomplete capture at best, or a complete computer collapse at worst...

So take our advice: if you have the chance of capturing in DV format, always do so, regardless of space and time limitations. After all, whoever said that video editing was not supposed to be demanding???

[Devil]

I'll add a third opinion to capture in DV.

Capturing, by definition, must be in real time. That is, 1 h of tape plays in 1 h and you have 1 h to capture it in. As DV doesn't even capture but just copy, this is no great shakes. With MPEG-2 or "DVD", which is also MPEG-2, you have to put the DV into memory AND transcode it in the same time (actually, you are permitted a slight over-run because of memory buffers).

However, if you take a DV file and then encode it to DVD-compliant MPEG-2, the chances are that your computer will take considerably more than 1 h to do so. Why can it not do it in 1 h, if it can do so when transcoded directly? The answer is simple. Direct transcoding cuts corners and the quality is poorer than with subsequent encoding for a given set of conditions. Furthermore, you don't have the same encoding flexibility to obtain the results you want.

So, I'm saying the same as my colleagues: when copying DV to DVD, I always capture in DV then subsequently encode.

[Trevor Andrew]

Hi babyleon

I agree with the replies---Capture to DV format.( the data is transferred)
(Capture to any other format and the data is re-coded)
We all refer to Mpeg 2, but when we capture we really mean select DVD

By selecting DVD you will capture to properties compliant for creating a Dvd.
Look at the options under the cogwheel.

If you select Mpeg you could be capturing to literally any settings.
Again look at the options, notice there are many more, some of which are not compliant for DVD.

By capturing to DVD you may not see any difference in quality from DV capture.
The discussion as to editing in Mpeg2 (DVD) will go on.

Give it a go and compare the quality difference. I certainly would be interested in your findings.