Bitrate calculator accuracy?

[moorthy]

I used a bitrate calculator to tell me that for a 200 minute avi, the settings for a 2-pass VBR encode should be MAX 9300, MIN 1100, AVG 2750.

(for a 4.7 Gig DVD, with 192 kbps audio)

Anticipating a 4.3 or so gig file, I was shocked to see that the end result (using TMPGenc, and a friggin' 19 hour encode) was in the 12 gig range.

How could that be.............?

[tito13kfm]

check your settings carefully, that file should have been well under the 4.3gig limit.

Or perhaps it has VBR audio, but that shouldn't account for THAT much difference.. it sounds like you need to double and triple check everything, make sure you didn't accidently choose Constant Quality setting.

If everything looks fine, then I don't know. Maybe somebody else has had similar experience.

Some more information would be helpful as well, is this a DivX/XviD, what is the audio encoded as (AC3, MP3, other?). What's the size of the original file (because if it's a crappy file to begin with than maybe you should just stick with CBR and not waste the extra time with the extra pass.

[moorthy]

The original file was a 25 gig AVI.

Audio PCM.

[ZippyP.]

Or perhaps it has VBR audio,

That'd be my guess. Open the file with Virtualdub and see if a VBR warning pops up. If it does then you can use Vdub-mp3 to extract the audio to a wav file.

[moorthy]

The video file was in the 11 gig range. The audio file in comparison, was rather small.

I have no idea of why it happened the way it did. I've done encodes in the past that have been fine.

I'm going to try a CBR encode set at 2750. It may end up looking like shite as there is plenty of fast action.

We'll see.....

[moorthy]

Bloody hell....it was operator error.

I accidentally set the AVERAGE at 9300.

Sorry.

[DaveS]

that's the classic 'error between the keyboard and the chair'

(well, we need something to keep ourselves entertained w/ our users at work)