Welcome Guest ( Log In | Register )

Vorbis RC3 quality settings
Jon Ingram
post Dec 22 2001, 15:42
Post #1

Group: Members
Posts: 315
Joined: 29-September 01
Member No.: 53

RC3 is almost ready to do, and now has two ways to specify encoding:
1) -m minimum -M -maximum b nominal
2) -q quality

The quality indication goes from 0, which is nominally 64 kpbs, to 10, which is nominally 480kpbs, and is a floating point number.

To get some indication of how bitrate changes as you change the quality setting, take a look here:


I (along with xercist from the #vorbis IRC channel) graphed bitrate-vs-quality for several well known samples, including hard-to-encode ones such as applaud.wav and fatboy.wav. The overall graph is as follows:


The big jump at q=5 is mainly down to the switching to lossless channel coupling. You'll also notice that the bitrate for q=n.99 is generally *larger* than that for q=n+1-- this is because the same settings are used for q in [n, n+1), and they are tuned for the lower end of that range.

Have fun.
Go to the top of the page
+Quote Post

Posts in this topic

Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:


RSS Lo-Fi Version Time is now: 26th November 2015 - 16:48