Did I chhose the wrong bitrate?

Videot wrote on 1/2/2005, 7:25 PM
I made project that was 89 minutes long & rendered it out to MPEG2. I had selected a bit rate of 7150,quality to best & progressive scan. so that I would be slightly under size so that I could put simple menu on it in DVDA. DVDA says that the size is 3GB's or 64% of disk capacity. This seems to be very low as I had expected a much larger file size-at least 92%. At first I assumed that I had made an error in settings prior to rendering. I then found a small change was needed in the file so I had to re render it all again. I used the same bit rate for a second time with the same results.

Is there any point doing it a third time & is any quality improvements likely to be noticeable? Was my chosen bitrate wrong? As far as I can see DVDA says it's interlaced & not progressive scan. Another puzzle?

Comments

rmack350 wrote on 1/2/2005, 9:05 PM
There's a good chance you'd just get the bitrate up higher than most DVD players can handle.

If it looks good, quit while you're ahead.

Rob Mack
B.Verlik wrote on 1/2/2005, 10:09 PM
3 GB for 89 minutes seems a little small for a 7150 bit rate. What was your max and min. bit rates? I would expect it to be closer to 4 GB for 89 minutes. I'm assuming its a variable bit rate.
Videot wrote on 1/2/2005, 11:07 PM
I only reset the max bit rate & left the other settings to the default figure.
B.Verlik wrote on 1/2/2005, 11:19 PM
Too bad. You, like most of us, got suckered by the default setting. The average, is your bitrate. The Max is where your video only occasionally hits and the same with the Min. The default is a pretty lousy default setting. Use the NTSC DVD setting (if you're not in PAL land). It should read something like: Max 8,000.000, Average 6000,000 and Min. 192,000 bps, then check your 'video quality slider', just above those settings, and Max it out to 31. I've never had any problems with these settings, but I've heard others argue about going above 7,500,000 bps.
BillyBoy wrote on 1/3/2005, 6:10 AM
For what its worth IF you use the default settings your DVD disk will be able to hold roughly 90 minutes, allowing for a typical menu system and up to two or three dozen chapters and special effects like having animated thumbnails and menu background music if you use DVD-A.

It can only be a rough guess, but I've made many both single file and multiple file projects and that's typically what I get away with. Roughtly a hour and a half worth that maxes out the disc at 3.8 GB or a tad more. Much depends on the contents, so if lots of action may result in the "average" bitrate creeping higher meaning you'll get less on the disc.

Me too... rarely go above the default bitrate... almost always just results in wasted space and can cause more problems with some DVD players.
mbryant wrote on 1/4/2005, 7:43 AM
Be very careful with defaults.

The "Default DVD Architect NTSC (or PAL) Video Stream" templates are fine; they have an average rate of 6000 which is around 90 mins.

But the one just called "Default", has an average of 4000, and other settings set to poorer quality. This should never be used.

As an earlier post said, it is the average rate you need to check and change. If your average is 6000, then I wouldn't worry about the file size. But I wonder if you used this default and are actually using 4000 for the average.

Mark