is maestro over cautious?

[lancer]

I'm mastering a DL disc at the moment and have run into an error message with maestro when compiling the disc image.

it says that I have exceeded the max bitrate and there has been buffer underrun. how can that be?

I have an M2v file of 5.126,459gb
and six soundtracks.

1. 5.1 DD at 448kbps for 383.014mb
2. 2.0 pcm track at 1536 kbps for 1.313,191gb
3. 2.0 ac3 224kbps for 191.057mb
4. 1.0 ac3 128kbps for 82.075mb
5. 1.0 ac3 128kbps for 81.795mb
6. 2.0 ac3 160kbps for 136.795mb

now. I was under the impression that DVD had a max bitrate of 10mbps

I set the m2v video file to have a max bitrate of 7000 and an average of 6000mbps.

adding up the audio comes to 96124 bps total.

in that case, how can maestro be throwing me an error message?

is it being cautious because it is close to the threshold? or is it not very accurate at calculating and erring on the side of caution?

[Mug Funky]

is it a green warning or a red stopped-dead-on-compile error? a green error can probably be ignored, but chances are there'll be a small stutter at that point, at least on some players (nowadays they're quite robust, and when they glitch it's not repeatable).

max 7 doesn't necessarily mean the true max is 7, and even that doesn't say much about the VBV simulation that spruce is doing (i think it's accurate, but sometimes it's a bit spazzy and spits out perfectly fine streams, while letting through stuff it probably should spit out).

btw, it's good practice to leave a little headroom with bitrates - 10.08 mbps max is a theoretical max, and poor replication, poor discs, dirty discs, dirty players, dirty fingers etc will effectively lower that allowable max bitrate. one thing you could do is calculate your max rates off 9.8 instead of 10.08...

btw, even spruce's own encoder hardware will cause green underflow warnings quite often (20% of the time? more?), so it's not something to worry about unless it's actually stopping the compile dead.

[edit]
from 9800 max i got 7176 max for video. if you have subtitles you're going to get problems :) try max 6500, or ditch some audio if you can (obviously that's not always possible). 6500 max is quite hideous really... you'd better have a good encoder and a clean master.

[edit 2]
btw, if it is a red warning you're getting, you can track down the offending bit if you snoop around a bit (look where the dotted line stopped, go to that movie, turn on bitrate profiler and look for a high spike), and re-encode the segment that's causing the problem. much much better and quicker than re-encoding the whole feature. just set a couple of chapter/punch points around the problem area, re-encode those frames (start at the first i-frame, end 1 frame before the end i-frame), place your playcursor on the in-point, right-click, insert segment at playcursor. that's should do it.

[lancer]

thanks for the reply.

the error is green, not a complete halt.

Mpeg muxing from the raw avi file was done via TMPGENC so I think it might be okay.

only way to try is on a player I suppose. I got a sony 7700 so I can soon see if it can cope.

[dvdboy]

I always calculated PCM at 1.7Mbps to give it a bit of extra headroom, simply because it being uncompressed taxes some systems more than others.

My 2p worth