File Size Limits

[Axel Slingerland]

I am using Fab 9.0.6.3, FYI...

I am trying to make some DVD's out of some movies I shot on our vacation, which are 1920p .MOV files, and some short .MP4 movie clips I downloaded from the Internet. The .MOV files are approximately 100Mb per minute, and a file that is 100Mb (1:00 long) shows on the bar along the bottom of the screen as "64\4300Mb". This implies to me that the 100Mb file is being reduced in size to 64Mb, and thus I could assume that the files would now be approximately 64Mb per minute, thus I could have approximately 67 minutes of video per DVD. Assuming of course that my math is correct...

But when I try to make a DVD with a 464Mb 320p .MP4 file it says it's too big. The largest .MP4 file I can burn is about 300Mb. It seems to me that if I can put 4,300Mb of multiple 1920p .MOV files, I should also be able to fit a 464Mb 320p .MP4 file. Yet I can't. Can anyone explain to me how this works?

[GregiBoy]

The 320p file will be expanded to DVD standard res for start and the MP4 codec expanded to MPEG2.

Just some rough maths per frame assuming a 16 x 9 aspect ratio.

Pixels/Frame
320p = 320 x 240 pixels = 76800 pixels
DVD = 720 x 480 pixels = 345600 pixels

You are at least quadrupling the number of pixels you are dealing with BEFORE then converting from MP4 to MPEG2 which roughly quadruples it again hence it won't fit.

[Axel Slingerland]

If that is the case, then 1920 x 1080 = 2073600. And that will certainly end up being much larger. And like I said, the larger files actually work, where as the smaller files do not. That is why this makes no sense to me. If larger fits, then logically smaller should as well...

[GregiBoy]

When the 1920 x 1080 = 2073600 is converted to 720 x 480 (345600), the number of pixels is reduced to a sixth of the size then expanded to 64Mb by the conversion to MPEG2.

Those files are not retained at 1920 x 1080.

PS: Don't forget we are only using rough approximations here.

[Axel Slingerland]

I understand that these are rough approximations. What I don't understand is why something smaller won't fit when something larger does. Because even if the 1920 x 1080 files are reduced to 720 x 480, that is still larger than 320 x 240. So there has to be some other reason why these MP4 files won't fit. And not knowing much (if anything) about any of this, I have no idea what it would be...

I just figured that since you can take a DVD with more data on it than a blank disk and shrink it down with DVD Copy and make it fit when you are copying it, that the DVD Creator would have similar capabilities. I found that 9.0.1.5 and up have a "Fit to Disk" option in DVD Creator, but the results of using it aren't that promising. (The DVD burned ok, but looks like crap...)

An even bigger mystery to me is why these .MOV files are the ones that work, since I have never had much luck with them at all. If I had known that was the format that my camera used I would have bought a different one for that reason.

[GregiBoy]

What is the duration of the 320p file?

MediaInfo is very useful in circumstances like these.

Free download, Google is your friend.

[Axel Slingerland]

Two hours.

I'll have a look at MediaInfo.

Google is good, but AVG Secure Search powered by Google is even better. I recommend to to everyone, even those who don't use AVG or Google.

Thanks!