Bitrates: CQ Problem

WOWIEGURL · #1 06-13-2004, 09:15 AM

I keep getting this no matter what tmpgenc template I use or how I load it in. I know for sure cq is supposed to be over 70 but this is sooo stupid.I usually get "low fence 70 and high fence 90" don't know why this time.

http://www.kvcd.net
CQMatic Version 1.2.06
Copyright Softronex Corporation, 2003.
All rights reserved.
Time: 23:50:00 Date: 06/13/2004
Ready!
Project: D:\script.tpr

what should I do?
Creating: CQMatic.tpr

D:\movie.mpg
Project resolution: 352x288
Execute.
Movie Time: 101
Average Bitrate: 861.8
Full Encode mode
Executing Prediction Phase...
Process started at 23:51:56
On 06/13/2004
Setting up initial sampling.
Using CQ of 70.00
Prediction cycle #1
Encoder started...
Process time: 12.50 minutes.
Encoder end.
File size difference = 0.658228
Low fence: 2.000000
High fence: 70.000000
Last CQ = 70.00
Current CQ = 46.08
CQ difference = 23.924026
Using CQ of 46.08
Prediction cycle #2
Encoder started...

kwag · #2 06-13-2004, 09:21 AM

Is that with one particular source

It seems that whatever it is you're trying to encode, is not very good material

-kwag

WOWIEGURL · #3 06-13-2004, 09:27 AM

its happened before but I have managed to get it back to to low 70 and high 90. Just that this is really pissing me off sinceI am using the exact same script for my previous conversions, and still having probs.

Dialhot · #4 06-13-2004, 10:05 AM

Quote:

Originally Posted by WOWIEGURL

Just that this is really pissing me off sinceI am using the exact same script for my previous conversions, and still having probs.

And what really piss me off is that you still doing things without understanding the slightest piece. Any video is different, any job need particular treatment and you will NEVER have something taht works in every situation

WOWIEGURL · #5 06-15-2004, 05:31 AM

its given me a high fence of 70 and low fence of 2 when I use the 352 * 240 ntsc template for 120mins... THis has happened 3 times now.... and the movie is in NTSC format . I don't understand why.

kwag · #6 06-15-2004, 09:50 AM

Quote:

Originally Posted by WOWIEGURL

THis has happened 3 times now.... and the movie is in NTSC format . I don't understand why.

When you say 3 times now, you mean with the same movie, or with 3 different movies

WOWIEGURL · #7 06-15-2004, 07:43 PM

3 movies

Dialhot · #8 06-15-2004, 08:13 PM

What are : min bitrate used, max bitrate used, avg bitrate set in CQMatic, audio bitrate configured in Calcumatic and length of the movie (in minutes) ?

kwag · #9 06-15-2004, 08:36 PM

And what script was used

WOWIEGURL · #10 06-17-2004, 06:57 AM

Okay I did a few experiments and realised that the only time there is a high 70 and low of 2 is when I use 2300 max and the result from .57*birate = aveerage bitrate as min. last time the avg bitrate was around 987. Thats when I began to get the weird readings. Also does the bitrate for audio affect the audio in the final product? Because lately when I do my encodings I find that when I play it on the tv the voices of the people are much deeper but on the computer it sounds fine.

Dialhot · #11 06-17-2004, 07:26 AM

Quote:

Originally Posted by WOWIEGURL

when I use 2300 max and the result from .57*birate = aveerage bitrate as min. last time the avg bitrate was around 987.

Okay in this case that means that your sources are so "slow" and easy to compress that with a min set to 0.57*AVG, the encoder waste a lot on bits in a lot of scenes and after this it doesn't have enought for encoding the rare action scenes that need them. That does not sound weird.
Personnaly I never used this 0.57*avg recommandation and always have correct results of CQMatic with the settings min=64 and max = 2300.

Quote:

Also does the bitrate for audio affect the audio in the final product? Because lately when I do my encodings I find that when I play it on the tv the voices of the people are much deeper but on the computer it sounds fine.

When you lower the audio bitrate, the first thing that is affected are the high frequencies. What you are calling "deep voice" is probably that : a lack of high frequencies that make voices sound "soft" and the words are hard to distinguish.
If you suffer really from this, do not use an audio bitrate under 160 kbps. But generally with 128 the human ear is correctly pleased.

kwag · #12 06-17-2004, 10:18 AM

Quote:

Originally Posted by WOWIEGURL

Also does the bitrate for audio affect the audio in the final product? Because lately when I do my encodings I find that when I play it on the tv the voices of the people are much deeper but on the computer it sounds fine.

Seems you encoded your audio at 48Khz instead of 44.1Khz.
Check that

-kwag

WOWIEGURL · #13 06-18-2004, 09:53 AM

yeah I encoded the sound at 48hz cause I thought thats what ntsc is.. I'll stick to 44100hz from now on. Also in my other thread where I had problems with the blurs with fast movement,pixelations and red & black boxes (Guides on using these programs? Newbie here) - thread, I was recommended to use the 2300 - max and .57*bitrate = avg bitrate - min bitrate in tmpgenc.It worked with the movie but when I found I had another movie to back up that also had fast movements thats when I found I had a high of 70 & low of 2 - when I assumed I need to adjust the max to 2300 and .57*bitrate = avg bitrate - min bitrate in tmpgenc . I also included the 2nd blockbuster linein the script as I was scared the end result would be blurry . when I reverted to the original settings of the template 352*240 - ntsc max 1800 & min 300m, everything was perfect except for the sound, which I realise now should be 44100hz at all times. I just want to know if I should continue using the max of 2300 and min of .57*bitrate = avg birate for movies that I want to backup that have fast moving scenes. I hope you understand what I said in this post.

Dialhot · #14 06-18-2004, 09:59 AM

Return to the thread where I told you that IT IS NOT POSSIBLE to give you min and max usable anytime. These values change according to the source.

No you can understand why I said that

So please, stop asking that. I repeat IT IS NOT POSSIBLE to answer to this question !

All I can tell you is that I have a min of 64 FOR ALL MY JOBS with no problem (on my standalone, things can be differents with yours). And I use 2300 as max for 90% of the time. A lower it to 2000 or even 1800 when I do extremly long movies (more than > 2h30)

I already said that to you a long time ago...

WOWIEGURL · #15 06-18-2004, 10:08 AM

but its sooo difficult to know what I should be uisng for max and min for movies that lots of action scenes. You don't when if you should upp the max or decrease the min to get the best quality possible. I guess I'll go back to using the template defaults then...

Dialhot · #16 06-18-2004, 10:24 AM

Quote:

Originally Posted by WOWIEGURL

but its sooo difficult to know what I should be uisng for max and min for movies that lots of action scenes.

The only help is called experience, and you earn it by doing... experiment.
Don't worry, one day you will do as I did : all your job in only ONE attempt.
But I am involved in the process since months

Quote:

You don't when if you should upp the max or decrease the min to get the best quality possible. I guess I'll go back to using the template defaults then...

I told you what I do personally. If in my sentence you do not see anything about the action scenes it's because I DON'T need to change anything in my settings for that ! All that count is the length of the movie.

I really don't see why you had these strange "red pixels", for me this has NOTHING to do with a problem of bitrate. I never see that anywhere ! So your situation is definitly special. And that is an other reason why we CAN'T answer to your question. Only you can.