IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
why the difference in bitrate?, same compression setting, but two different bitrates when encoding wit
jmcguckin
post Jun 21 2008, 02:23
Post #1





Group: Members
Posts: 52
Joined: 2-January 08
Member No.: 50051



hey guys, I was comparing the results of files extracted with EAC vs. CDex earlier, and I noticed that while the process using EAC took much longer, the end bitrates of almost every track were 8kbps less than the exact same tracks extracted with CDex. for instance-

01 - Nothing Is Sound.flac
using EAC, bitrate = 1065kbps
using CDex, bitrate = 1073kbps
02 - Stars.flac
using EAC, bitrate = 1062kbps
using CDex, bitrate = 1071kbps

and so on...

what I can't figure out is why there is that big of a difference between the bitrates when I thought I was using the exact same compression setting with both programs... if someone could explain the difference or suggest a new parameter string for me to use with CDex to achieve the same bitrate results as EAC, I'd appreciate it (only because using EAC takes much more time than I have to work with).

if it helps, here are my parameter strings-
EAC-
CODE
-T "artist=%a" -T "title=%t" -T "album=%g" -T "date=%y" -T "tracknumber=%n" -T "genre=%m" -8 %s

CDex-
CODE
-8 -V -A tukey(0,5) -o %2 -T "artist=%a" -T "title=%t" -T "album=%b" -T "date=%y" -T "tracknumber=%tn" -T "genre=%g" -


thanks in advance for the help!


--------------------
Archive- FLAC (-v 8)
Portable- QuickTime AAC (True VBR/-q 77)
Go to the top of the page
+Quote Post
gib
post Jun 21 2008, 13:42
Post #2





Group: Members
Posts: 227
Joined: 20-January 03
From: A Tropical Isle
Member No.: 4640



The difference is the "-A tukey(0,5)" command.

Also, there really isn't any reason why EAC needs take so much longer than CDex. Perhaps you're using secure mode with cache flushing enabled? That'd certainly slow down EAC relative to CDex.
Go to the top of the page
+Quote Post
jmcguckin
post Jun 22 2008, 00:05
Post #3





Group: Members
Posts: 52
Joined: 2-January 08
Member No.: 50051



QUOTE (gib @ Jun 21 2008, 08:42) *
The difference is the "-A tukey(0,5)" command.

Also, there really isn't any reason why EAC needs take so much longer than CDex. Perhaps you're using secure mode with cache flushing enabled? That'd certainly slow down EAC relative to CDex.

ya, I went ahead and switched it over to the standard mode ("jitter-correction" mode) and it seems to be working much faster... I guess there really isn't much point in using error correction if I can see that the disc is clear of any major scratches, but I have a couple scratched discs I might compare extraction results of, just to see how different the sound quality is. anyways, thanks for the help!


--------------------
Archive- FLAC (-v 8)
Portable- QuickTime AAC (True VBR/-q 77)
Go to the top of the page
+Quote Post
gib
post Jun 22 2008, 02:45
Post #4





Group: Members
Posts: 227
Joined: 20-January 03
From: A Tropical Isle
Member No.: 4640



QUOTE (jmcguckin @ Jun 21 2008, 13:05) *
I guess there really isn't much point in using error correction if I can see that the disc is clear of any major scratches
Extracting audio is a funny thing. I've seen odd issues with pristine discs, so you never know. In any event, you should really enable AccurateRip if you haven't already. It is your friend.
Go to the top of the page
+Quote Post
jmcguckin
post Jun 23 2008, 22:07
Post #5





Group: Members
Posts: 52
Joined: 2-January 08
Member No.: 50051



QUOTE (gib @ Jun 21 2008, 21:45) *
QUOTE (jmcguckin @ Jun 21 2008, 13:05) *
I guess there really isn't much point in using error correction if I can see that the disc is clear of any major scratches
Extracting audio is a funny thing. I've seen odd issues with pristine discs, so you never know. In any event, you should really enable AccurateRip if you haven't already. It is your friend.

well, I'll assume AccurateRip is to EAC as "Paranoia, Full" mode is to CDex (obviously with EAC's version typically yielding better error correction results), and I've been using Paranoia for some time now, but I read somewhere that using it could damage my CD drive? granted, my laptop is under warranty, but I'd still like to use the optimum settings without inadvertently causing damage to my computer in the process.

---

on a side note, I just tried using CDex and none of the suggested parameter strings on here work (including the one that I listed above)... for some reason it rips the WAV to the hard drive and then skips to the next track without sending the WAV to the encoder. any idea why?


--------------------
Archive- FLAC (-v 8)
Portable- QuickTime AAC (True VBR/-q 77)
Go to the top of the page
+Quote Post
Dynamic
post Jun 24 2008, 00:47
Post #6





Group: Members
Posts: 795
Joined: 17-September 06
Member No.: 35307



EAC's Secure mode reads the CD at least twice and can involve shuttling the read-head back and forward numerous times. Test and Copy in non-secure can rip twice without the shuttling and still be secure when the CRCs match.

AccurateRip in EAC or dBpowerAmp will compare your rip against other people's rips of the same CD pressing and report a confidence rating (number of matching rips found). It should safeguard against that fairly rare error that gives rips with the same false bit sequence twice in succession.

It also allows you to use any non-secure mode like Burst Mode with confidence that if your rip is reported as accurate with sufficient matches (say 2 or more) then it will be fine. If it's 1 or fewer (or if errors are reported by EAC), then you should probably make a note of the CRC reported in non-secure mode (and/or the AccurateRip CRC) then re-rip in Secure mode to be more sure of accuracy.

A single read, like Burst Mode will probably put the least stress on the components, and if it's verified against numerous other rips by AccurateRip it should give you greater confidence than Secure mode without AccurateRip would alone. It's also very likely to be a good deal faster.

AccurateRip does require correct Read Offset setting but will probably be better than EAC alone at confirming the offset (i.e. wider selection of discs to verify it).
Go to the top of the page
+Quote Post
bhoar
post Jun 24 2008, 01:31
Post #7





Group: Members (Donating)
Posts: 612
Joined: 31-May 06
Member No.: 31326



QUOTE (jmcguckin @ Jun 23 2008, 17:07) *
QUOTE (gib @ Jun 21 2008, 21:45) *

QUOTE (jmcguckin @ Jun 21 2008, 13:05) *
I guess there really isn't much point in using error correction if I can see that the disc is clear of any major scratches
Extracting audio is a funny thing. I've seen odd issues with pristine discs, so you never know. In any event, you should really enable AccurateRip if you haven't already. It is your friend.

well, I'll assume AccurateRip is to EAC as "Paranoia, Full" mode is to CDex (obviously with EAC's version typically yielding better error correction results), and I've been using Paranoia for some time now, but I read somewhere that using it could damage my CD drive?


Actually, AccurateRip will save your drive from wear and tear.

AccurateRip is not a ripping strategy (like "secure" or "paranoia" modes) at all. Instead it is a online registry of computational hashes of ripped audio data. If you rip in burst mode *and* you get an AccurateRip match of 2 or higher, then there's probably no point in reading any of the track's data more than once. You end up with faster rips and less wear and tear on the disc and drive. Winning all around.

-brendan


--------------------
Hacking CD Robots & Autoloaders: http://hyperdiscs.pbwiki.com/
Go to the top of the page
+Quote Post

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: 23rd July 2014 - 12:41