Quantcast CQ 'Narrowing in' Formula - digitalFAQ.com Forums [Archives]
  #1  
01-14-2003, 12:15 AM
Daagar Daagar is offline
Free Member
 
Join Date: May 2002
Posts: 158
Thanks: 0
Thanked 0 Times in 0 Posts
I know this was posted somewhere, but heck if I can find it. I'm looking for the current technique for 'narrowing in' on the correct CQ value to achieve a certain sample size (ie., sample 1 is 10.1meg at CQ60, so to get it close to 11.8meg I need to use CQ??) Right now I'm doing a horrible hit and miss job
Reply With Quote
Someday, 12:01 PM
admin's Avatar
Site Staff / Ad Manager
 
Join Date: Dec 2002
Posts: 42
Thanks: ∞
Thanked 42 Times in 42 Posts
  #2  
01-14-2003, 12:36 AM
kwag kwag is offline
Free Member
 
Join Date: Apr 2002
Location: Puerto Rico, USA
Posts: 13,537
Thanks: 0
Thanked 0 Times in 0 Posts
Hi Daagar,

Say you want 12MB and you started with CQ=60 and file size is 10.0MB. Try 12/10 = 1.2 and multiply current CQ (60) X 1.2 = 72. From now on, it will be easier, just half of half or double ( you're still with me ). So if at CQ=72 sample file size is over 12MB, just try half way between 60 and 72, so try CQ=66. Next run either 69 or 63. You get the point . You should hit target in 3 to 4 runs.

-kwag
Reply With Quote
  #3  
01-14-2003, 10:44 AM
Daagar Daagar is offline
Free Member
 
Join Date: May 2002
Posts: 158
Thanks: 0
Thanked 0 Times in 0 Posts
Excellent, thanks! Though I do notice that this method will get skewed very quickly if your CQ happens to hit 80+ But for most movies, this works great.
Reply With Quote
Reply




Similar Threads
Thread Thread Starter Forum Replies Last Post
KVCD: does this formula only work with CQ_VBR?? Adder Video Encoding and Conversion 1 01-22-2003 02:50 PM
File size prediction formula girv Avisynth Scripting 39 01-10-2003 05:23 PM
Another result from new formula SansGrip Avisynth Scripting 6 12-27-2002 03:09 AM

Thread Tools



 
All times are GMT -5. The time now is 05:11 PM  —  vBulletin © Jelsoft Enterprises Ltd