KVCD: Calculating file size with NTSC 29.97fps captures?
 

I am digitizing hour long shows with AVI_IO (NTSC 720x480 29.97fps, MJPEG quality=19), editing out the commercials and applying deinterlace filter with Virtual Dub, and frame-serving it into Tmpgeng. I then use the KVCDx2 2-disc template since my video is only 42-46 minutes.

Is there any way to calculate the approximate file size with various CQ's before the long encoding process? (this could work both ways; I could decrease the CQ for more minutes, or increase for fewer minutes, to fill an entire disk)

Hi davelanton:

There's really no way to calculate CQ mode.
As a guide, if your footage is 23.976fps, the 2-CD KVCDx2 template should give you 2 hours, maybe even more, in 2 CD's.
At 29.97, your time is reduced by about 20%.
So it should give you around 100+ minutes on 2 CD-R's.
The KVCDx2 2-CD template has a CQ value of 70. There's hardly any increase in visual quality beyond that point. Just an increase in file size.

kwag

I think, if it's full screen, the time will be reduced some more.

Here are the results so far:

Using KVCDx2 2-disc template (CQ=70) with NTSC 29.97fps episodic television (44:30-45 minutes in length with no commercials):

My filesizes range from 615MB-730MB. All were episodes of "Alias" which is high action. I was surprised to see such a wide range in file sizes using the same CQ. On the 730MB file, I reencoded with a CQ=62 and the new filesize was 660MB. I didn't see too much difference in video quality.

The only filters I am applying in Virtual dub is deinterlace. Since my source is DirecTV, I chose not to apply smoothing.

Soon I will try encoding 60 minute commercial-free dramas, I'll let you know how it goes.

Kwag...

I used yer 1 cd template and got some way bigger file sizes then i expected. I had a 80 min 29.99 fullscreen capture and left the cq at 50 and the file size was 920.. I didnt expect that :) needless to say i think i might use yer old template. I had better file sizes with it and still had a great picture.

Is there something that i can do. I remember reading somewhere, you (or someone else) saying that you could reduce your file size if your fps was 23.97 by like 20%.. I might be wrong.. But if so how would it be possible?

Thanks

Ooops...


Pays to read i guess :)

tks