Why are .dv files so large?

[mazjazz]

I'm sure you have discussed this in the past, but I couldn't find anything recent using search.

I have several .mpeg files created fom EyeTV that I would like to edit on iMovie and burn on a DVD.

I looked a various topics in this forum and the only one that worked was to use Toast 6 to create a .dv file. The original .mpeg file is 424MB. The resulting .dv file is 8.54GB. The sound and video quality actually seems poorer that the original. Anyway, this is only a 43 min. video, why does it take 2 - DVD's to capture it? It doesn't make any sense to me. Normal 2 hour movies fit fine on one DVD with lot's of extra stuff in it.

Is there something wrong with my approach? Is there anything I can do to reduce the size and keep the quality?

I've been working on this one for over a week and find the whole process very frustrating. I guess I was foolish enough to actually believe Steve Jobs at the SF Macworld when he promoted iLife for "the rest of us". Apple is so far away from making video easy to use it's unbelievable.
Sorry for dumping and grandstanding, but I do blame Apple for my frustrations.

I would appreciate any help or feedback. Thanks.

[Frobozz]

All the various video formats are confusing. You might want to spend some time looking through the DVDRHELP glossary and "What is DVD-R" at the upper left menu of this site. Basically, DV is uncompressed video and DVDs have compressed MPEG2 video.

So what is it you're trying to do? Why do you want to edit your EyeTV mpegs? If you just want to cut out the commercials you can use an MPEG cutter such as the one included with Gumby http://gumby.misplacedmac.com

The EyeTV video is recorded as MPEG 1, which is a lower resolution and size than MPEG 2. You won't get DVD-quality video from those files. It can be recorded to a DVD and played on most DVD players, but it will look like a so-so VHS recording.

[mazjazz]

Thank you Frobozz for your reply. My father died last year and I want to put together a DVD or two of him for our family. I have video clips from my new digital camcorder of him in 2002 and 2003 that easily import to iMovie. But I have 8 years of tapes of my father I took using an analog camcorder. EyeTV offers a feature were I connect my old camcoder to it and it will download the tapes on my HD as MPEG files.

I would like to combine these files chronologically with the digital clips and burn DVD(s).

BTW, I thought I could split my 8.54GB .dv file I produced using QT. I ended up with Part I as a 8.53GB .dv file and Part II as a 8.56GB file. This is poetic justice.

Can one go from MPEG to MPEG2 and edit in iMovie?

[TugBoat]

Have you tried connecting the Analog 'corder to a VCR in, Digital 'corder to VCR out, then go FW to iMovie? Your best bet would be to skip the MPEG as capture. All Apple's editing software is DV based as that is the preferred editing medium. MPEG is a delivery format that doesn't take to editing well. My Sony Digital 'corder says it will play analog tapes as well as digital, I've never tried it. It would be nice if yours did 8)

Edit
An Apple Helper (He has a book out) explained it this way,
"Exporting to DV is your only option. There is no simple way to work with MPEG material. MPEG is not a production format. It was never intended as a production format. MPEG is intended as a delivery format. It's compression is not frame based the way DV compression is. It's compression is based on GOPs (Groups Of Pictures). Because the compression is spread out over 15 frames it's really difficult to edit frame accurately without doing some heavy extrapolation underneath the hood about which frame you really mean and how the rest of the compression will take place around it. As far as I know there is no MAC based editor that will do this properly."
This was discussing FCE. Basically if you want to edit, you have to export the clip to DV. The best/smallest DV codec is DV/DVCPRO-NTSC at 3.6MB/s.
Hope this helps.

[The village idiot]

Just to make things clear... DV format (yes a real standard) is about 13GB per hour or 25Mbps. It is a compressed format, at approximately 5:1

http://www.adamwilt.com/DV-tech.html

[havema-1]

> The original .mpeg file is 424MB. The resulting .dv file is 8.54GB.

You can break the exported DV files to smaller <2G segments iMovie can import with these handy AppleScripts:

http://www.danslagle.com/mac/iMovie/tips_tricks/6003.shtml

DV is compressed 5:1 so DV files are actually quite small with only 13G/hour... DVD is heavily compressed so the file is smaller.

[terryj]

Thank you Frobozz for your reply. My father died last year and I want to put together a DVD or two of him for our family. I have video clips from my new digital camcorder of him in 2002 and 2003 that easily import to iMovie. But I have 8 years of tapes of my father I took using an analog camcorder. EyeTV offers a feature were I connect my old camcoder to it and it will download the tapes on my HD as MPEG files.

I would like to combine these files chronologically with the digital clips and burn DVD(s).

BTW, I thought I could split my 8.54GB .dv file I produced using QT. I ended up with Part I as a 8.53GB .dv file and Part II as a 8.56GB file. This is poetic justice.

Can one go from MPEG to MPEG2 and edit in iMovie?

Here's what you have to remember:
Mpeg(1) is the final output file.
This is what you want to get to.
You will need to start in something else that is compatible with iMovie.
iMovie is based around DV, which is the preferred editing standard, true.
But since iMovie 3.01, it has incorporated QT and thus now accepts
QT movie files as well through import.

For your EyeTV clips, first since I am unfamiliar with EyeTv, i would
see if it would allow you to capture in the clips as QT .mov files.
If So, great we are half way there. If not, then we would take the following steps.

Open an .mpg(1) file created in EyeTV in ffmpegx.
Demux the file into elementary streams ( .m2v and .ac3 or .aiff audio)
Open the .m2v file in QT Pro 6.5.
Open the .aiff audio in QT Pro 6.5.
Select all the video, copy to clipboard.
Select the audio, Edit-->add scaled the video to the audio.
Save the file as a self contained movie file.
Repeat for each MPEG.

Once done, you can then open iMovie, and then import the .mov clips
into iMovie's clip shelf, and edit away by dragging into the timeline.

Steve Jobs was correct in his assesment of the "Digital Lifestyle",
provided you were not trying to do anything else but hook a
digital camera in via FW and import into the Mac. Certainly,
if he had known we would be ripping/editing mpg-1 and mpg-2
files, trying to import analog video, digitize vinyl records, capture
tv shows, and god knows what else, iLife would probably have never made it to market in the first place!

[Frobozz]

If all this doesn't have your head spinning, my suggestion is to use your digital camcorder instead of the EyeTV to bring in (capture) the old video to your Mac as DV. Most, but not all, digital camcorder have a digital passthrough feature that allows you to plug in the analog video from your VCR and pass through the video to your Mac just as you did when you imported your digital movies.

Using MPEG 1 at any stage significantly degrades the picture quality. I don't think you want to do this with a project as important to you as this one.

Good luck to you. And I commend you for taking on such a meaningful project.

[mazjazz]

Thank you TugBoat, The village idiot, havema-1, terryj and Frobozz. I took TugBoat and Frobozz suggestions. My digital camcorder does have a pass-through feature. I connected my old analog camcoder to the digital, made a setting in the digital as stated in the manual and connected the digital to my Mac via FW. I have been able to import the old tapes directly to iMovie. Yeah! I'm still gathering the old tapes and haven't yet burned a dvd, but my hopes are high now that I don't need to deal with MPEG.

Thanks again. How did you guys get so knowlegable? Thanks to The village idiot for pointing me to DV technical information. Thanks to havema-1 for pointing me to Applescripts that can break a large dv file into smaller pieces. Terryj, thanks for the details on how to convert mpeg to mov. Your right, I'm afraid to say that we can't expect iLife to do all these things.

[deadsierra]

Thanks again. How did you guys get so knowlegable?

Exactly the way you just did. Think about your level of knowledge when you first started this thread, then compare it to now. Yep, you're smarter. Oh, and yes, I did label myself as one of the "knowledgeable" people for the purpose of this post. I doubt I really would fit in that group myself though...

[terryj]

your welcome, mazjazz.