digitalFAQ.com Forums [Archives]

digitalFAQ.com Forums [Archives] (http://www.digitalfaq.com/archives/)
-   Video Encoding and Conversion (http://www.digitalfaq.com/archives/encode/)
-   -   what's the difference between CQ, CBR, VBR, and CQ VBR ? (http://www.digitalfaq.com/archives/encode/6411-difference-between-cq.html)

raven2707 10-30-2003 02:59 AM

what's the difference between CQ, CBR, VBR, and CQ VBR ?
 
Im using dvd2avi. And i was wondering, whats the difference between.
CQ
CBR
VBR
and CQ VBR.
And which one to use with a high motion movie?

Dialhot 10-30-2003 04:24 AM

CBR = constant birate. The bitrate used is the same in slow action scene than in high action. The last ones are very often blocky and pixelated because they need more bits but they aren't available.

All other modes are VBR modes (Variable Bitrate).

What you call "VBR" is probably "2-pass VBR" : the encoding is done in two passes, the second one using the first one to adjust the bitrate variation in order to match the final target size you want.

Problem : bitrate repartition accuracy is lesser than it is in CQ and you need twice the time for encoding.

CQ = constant quality = you fix the "visual quality" of your picture (0 = very bad, 100 = very good, like in jpg for images). The bitrate is adjusted in order to keep that quality.

Problem : you can't know the final filesize

CQ_VBR : a CQ mode using an other algorythm (for what I know).

We use CQ for res > VCD (352*240/288) and CQ_VBR below.
The results are far better that 2-pass VBR. And never use CBR :-)

raven2707 10-30-2003 05:02 AM

Ok thanks dailhot.
Now i have used CQ with a backup avi from dirty dancing. When i use dvd2avi the final result is a good quality movie but the movie sometimes freezes and the audio along with it.
Is there a sollution for this problem?

Dialhot 10-30-2003 06:13 AM

Where do you see this freezing ? ON your PC or your sandalone player ?

raven2707 10-30-2003 06:30 AM

Well it works perfect on the pc but it freezes on the standalone player.

Dialhot 10-30-2003 08:16 AM

That means that you standalone player do not support the particular settings you choosed for you KVCD.

Can you give use the complete parameters of your KVCD ?

MPEG1 or 2 ?
Muxed as VCD or SVCD ?
Burnt as VCD or SVCD ?
Min and Max bitrate used ?
Resolution used ?
Audio samplerate (in KHz) ?
Medium used ?
Authoring/Burning tool used ?
Burning speed ?

incredible 10-30-2003 11:07 AM

... lets add some:

Encoding Buffer Size?
Enabled "padding not to be lower than min Bitrate" ... on or off?

Dialhot 10-30-2003 11:14 AM

Quote:

Originally Posted by incredible
... lets add some:

Geez... I realise now why newbies always tell me that KVCD is a hard stuff. I never realize how much things have to be checked :-)

kvcd is for :i: that can :book:, not for :imstupid: that :drink: :-)

incredible 10-30-2003 11:23 AM

:D :lol: :lol: :lol:

jorel 10-30-2003 11:27 AM

Quote:

Originally Posted by Dialhot

kvcd is for :i: that can :book:, not for :imstupid: that :drink: :-)

Phil.....you can write in portuguese too!

:lol:

raven2707 10-30-2003 03:32 PM

Well thats a lot of info your asking from a newbie!
I now started using this guide: http://www.angelfire.com/film/kvcd/g.../index_en.html
But when i get high movement in the movie like dance scenes. It just keeps stuttering!

raven2707 10-30-2003 03:36 PM

## DLL Section ##
#
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\MPEG2Dec3.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\GripFit_YV12.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\STMedianFilter.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\asharp.dll")
LoadPlugin("C:\Program Files\AviSynth 2.5\plugins\undot.dll")
#
####

## Defined Variables and Constants ##
#
MaxTreshold = 1.50
scd_trigger = 30 # Scene change trigger value.
nf = 0 # Current frame.
#
####

## Main section and static filters ###
#
AviSource("D:\Films\Om te bewaren\dirty dancing.avi")
#
undot()
Limiter()
asharp(2, 4)
GripCrop(352, 288, overscan=2, source_anamorphic=false)
GripSize(resizer="BicubicResize")
STMedianFilter(8, 32, 0, 0 )
MergeChroma(blur(MaxTreshold))
MergeLuma(blur(0.2))
#
#

## Dynamic Linear Adaptive Filtering and Scene Change Detection ##
#
# ( Portions from AviSynth's manual ) - This will apply temporalsoften to
# very static scenes, and apply variable blur on moving scenes.
# We also assign a variable - and this is why a line break is inserted:

ScriptClip("nf = YDifferenceToNext()"+chr(13)+ "nf > 2.5 ? asharp( -(fmin((nf/30), 1)), 0 ) : \
TemporalSoften(2,7,7,3,2) ")

#
# Scene change detection ( kwag ) - If a scene change is detected, we
# blur heavily. This affects the scene before and the one after the
# scene change, thus providing a softer transition for the encoder instead
# of a sharp "spike".
# If it's not a scene change, then we just blur dynamically, depending on
# the action.

ScriptClip("nf > scd_trigger ? asharp( -2,0) : asharp(0,0) ")

#
#
#

GripBorders()
#LetterBox( Your_Values_Here ) # Depends on situation. Use MovieStacker!
Limiter()

#
#
## Functions ###

function fmin(float f1, float f2) {
return (f1<f2) ? f1 : f2
}

#
####

raven2707 10-30-2003 03:39 PM

mpeg1
i used a divx avi as my source file
I used Nero.
burning speed 8

incredible 10-30-2003 04:28 PM

Quote:

Originally Posted by raven2707
Well thats a lot of info your asking from a newbie!

But still we need the right answers which do belong to the questions above! ;-)

BTW: I don't gonna quote the script you postet but this is the "rare groove" version of the MA script and its out of date! And should not associated with your stuttering dancing scenes!

We asked you for the max and min bitrate you set in TmpgEnc BECAUSE "dancing scenes", therefore fast movement could mean high bitrate peaks!
And therefore I give you the hint to LOWER your max bitrate .... but this depends upon to which value your max bitarte is set actually!
So let us know, AND also the value of your VBV Buffer size *please*

Open TmpgEnc, watch the questions above about your settings in TmpgEnc ... look and post them here ... so we find a solution!

;-)

Jellygoose 10-30-2003 04:35 PM

Watch out Raven! That Script you're using is VERY OLD!
Check out the newest optimal script!

incredible 10-30-2003 04:50 PM

Thats why I called it "rare groove" :D

raven2707 10-30-2003 05:56 PM

Well guys, im totally lost here but i got the darn thing working. It was just a matter of burning it as svcd with vcd easy. But my next questions are: What is THE best script? and second, how to put subtitels in the movie? Could someone please help me one last time.
Its very nice of you all that you help this newbie out! BIG THANKS! :lol:

Dialhot 10-30-2003 06:27 PM

Quote:

Originally Posted by raven2707
It was just a matter of burning it as svcd with vcd easy

Now you understand why among all the questions there were "what is the burning mode" and "what is the authoring tool you used".
Every single thing is important for determining what can be the freezing problem.

Quote:

What is THE best script?
There is a section on the forum called "Optimal script". I let you guess why ;-)

Quote:

how to put subtitels in the movie? Could someone please help me one last time.
There is also a subtitle forum ;-). For this one I can tell you that you wll need a plugin called "Vsfilter". Do a search on the forum to find were you can find it.


All times are GMT -5. The time now is 06:31 PM  —  vBulletin © Jelsoft Enterprises Ltd

Site design, images and content © 2002-2024 The Digital FAQ, www.digitalFAQ.com
Forum Software by vBulletin · Copyright © 2024 Jelsoft Enterprises Ltd.