Secure ripping

From Hydrogenaudio Knowledgebase
Revision as of 22:08, 12 August 2008 by HotshotGG (Talk | contribs)

Jump to: navigation, search

Secure Ripping

What is Secure Ripping?

Secure ripping is the process of making sure there were no errors during the extraction of audio from a CD. Popular Windows CD rippers, such as CDex and EAC try to ensure a bit-perfect rip for every track by checking the results, and re-reading any bad areas (from scratches) as many times as needed using read offsets, etc. Max and Rubyripper provide similiar results as alternative secure rippers for Mac OS/X and Linux/BSD respectively using their own effective correction mechanisms.

A bit-perfect rip may not always be possible, and so these programs (EAC especially) will report on any errors that could not be corrected for various reasons, allowing you to examine or attempt to correct the problems by analyzing a log file, using AccurateRip, or by looking at other drive databases.

Secure Ripping Comparison

EAC and dBPowerAMP

EAC and dbPowerAMP both feature powerful correction mechanisms that works with your CD-ROM drive. Some of these features include AccurateStream, Caching, C2 error pointers, and AccurateRip.

EAC has two additional modes that can be configured. One is known as "Secure Mode" and the other is known as "Burst Mode". Secure Mode is the recommended mode to use as it goes through the pain staking process of over-anaylzing CD's that may have scratches on them and correcting any bad sectors of audio data. Burst Mode is used for CD's that either have "copy protection" on them or are extremely scratched. It's considered a last ditch effort to recover the audio data from your CD's.

Accurate Stream

Accurate Stream is the ability to avoid jitter. Each CD drive reads audio discs slightly out (a number of samples), if your CD drive supports 'Accurate Stream' it will be a constant value, this should be the same for each particular make and model of CD-ROM Drive

Caching

Caching is the ability of the CD-ROM drive to hold a certain amount of samples in a buffer. Every CD-ROM cache can be "flushed".

C2 Error Pointers

CD-ROM's have differing levels or error recognition and correction. C2 error pointers are read errors by a compact disc that can usually be detected by error detecting and correction scheme.

AccurateRip

AccurateRip is a drive database that stores read offsets for a number of user submitted drives that allows you compare your CD rips to other people's. You can anaylze offset corrections on each drive and discover how it varies from drive to drive. AccurateRip database also lists what drives have AccurateStream, cache audio data, and use C2 error pointers.

Note: AccurateRip due to it's liscensing agreement only works with EAC and dbPowerAMP.

CDex

CDex externally uses the cdparanoia libraries. It is a bit different than most other CD-DA extration tools. It contains few-to-no extra features ("Too many features spoil the broth"), concentrating only on the ripping process and knowing as much as possible about the hardware performing it. cdparanoia will read correct, rock-solid audio data from inexpensive drives prone to misalignment, frame jitter, and loss of streaming during atomic reads. cdparanoia will also read and repair data from CDs that have been damaged in some way using interpolation and padding sectors with silence or 0 bytes.

Accurate Stream

Question: Does cdparanoia work on drives that support AccurateStream?
Yes: cdparanoia works on drive that support AccurateStream

Caching

Question: Does cdparanoia work on drives that support caching? No: cdparanoia works best on drives that don't support caching.

C2 error pointers

No: The current existing libraries do not utilize or support C2 error pointers

Max

Rubyripper

External links