title
Products            Buy            Support Forum            Professional            About            Codec Central
 
Results 1 to 9 of 9

Thread: Checking Accuraterip retroactively does not work as should (OSX)

  1. #1

    Checking Accuraterip retroactively does not work as should (OSX)

    Hi there, I'm a long time user of dBpoweramp for ripping CDs on my mac. As most of you probably know, sometimes you get some discs that just don't want to play nicely with your drive, computer, software, or a combination of all three. When this happens, I tend to rip either on a different drive, or using iTunes. I am currently ripping a CD where this is the case. There are no serious scratches to the disc that I can see, but one track is not ripping accurately with dBpoweramp, whereas the others are. I have tried a different drive, to no effect, so I have now ripped the CD using iTunes (to .wav, 16 bit). Now, when I check the files ripped using iTunes with PerfectTunes, I get the message that the entire disc is not present in the AccurateRip database. I know this isn't true, as I had a number of tracks verified when I ripped with dBpoweramp. I've had a number of instances where PerfectTunes just doesn't seem to work with me. For example, I wanted to check the accuracy of a number of .flac files from albums that I ripped years ago, and PerfectTunes claimed that the files were not lossless. I don't know if it's still teething problems in the Mac version, or if I am somehow doing something to produce error messages, but PerfectTunes' AccurateRip section very seldom works for me in the way that it should, which is a shame. Can anyone suggest a way in which I may be making some idiotic mistake when using the software? As this does seem more likely than the software itself being flawed. Thanks!

  2. #2

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    Just to add to this, as I've just encountered it, I often get another error when attempting to check files: "Cannot Check: Track Different Length Than CD Original"

  3. #3
    Administrator
    Join Date
    Apr 2002
    Posts
    42,062

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    They are all different reasons why the lookup cannot take place:

    Cannot Check: Track Different Length Than CD Original

    This one is a fundamental, something has changed the track length, you are never going to get an accurate rip match if the track length has been altered.

    "PerfectTunes claimed that the files were not lossless"

    The tracks have to be 16 bit, 2 channel, 44KHz to be verified against accuraterip as it is CD based.

    About the first issue, the lookup requires the lead in track length, this is not present after ripping, normally it is 2 seconds so it can be guessed, we also have a database of millions of discs with the lead in times, but if it is not 2 seconds and not in our database then you cannot get the disc id to lookup correctly with a bunch of tracks.

    All these issues are not related to perfecttunes, but your files and how Accuraterip can be reverse lookedup.

  4. #4

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    Quote Originally Posted by Spoon View Post
    They are all different reasons why the lookup cannot take place:

    Cannot Check: Track Different Length Than CD Original

    This one is a fundamental, something has changed the track length, you are never going to get an accurate rip match if the track length has been altered.

    "PerfectTunes claimed that the files were not lossless"

    The tracks have to be 16 bit, 2 channel, 44KHz to be verified against accuraterip as it is CD based.

    About the first issue, the lookup requires the lead in track length, this is not present after ripping, normally it is 2 seconds so it can be guessed, we also have a database of millions of discs with the lead in times, but if it is not 2 seconds and not in our database then you cannot get the disc id to lookup correctly with a bunch of tracks.

    All these issues are not related to perfecttunes, but your files and how Accuraterip can be reverse lookedup.
    This is pretty much what I expected, thanks for your detailed reply. Is there any way that the lead in time for a rip can be "re-inserted" manually? As the error message is that the track is a different length rather than a more emphatic "album not in accuraterip" I assume those albums are present in the database?

    Also, about the tracks needing to be 16 bit/2 channel/44KHz: is this the minimum requirement or an exact one? For example I have some albums that are 24 bit/44.1KHz, as well as 24 bit/48KHz - if I "downgraded" these to 16 bit (which is what I would prefer anyway) is it more likely I will get a better result through PerfectTunes?

    Thanks again

  5. #5
    dBpoweramp Guru
    Join Date
    Feb 2014
    Posts
    1,540

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    AccurateRip is based on a database storing checksums for ripped Audio CDs (red book standard). Audio CDs have a resolution of 16bit per channel (2 channels ) and a sample rate of 44.1 kHz. So every other resolution or sample rate is not corresponding the Audio CD standard and can't be compared with AccurateRip checksums therefore.


    Dat Ei

  6. #6
    Administrator
    Join Date
    Apr 2002
    Posts
    42,062

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    It is not possible to enter the lead in time.

    There is no way of knowing if a track is present, they cannot be checked if the lengths are not correct.

    If the audio has changed from the CD source, then reconverting back to cd source will not give an accuraterip result, changing frequency and sometimes bit depth is a lossy process, the original 44KHz 16 bit track is lost.

  7. #7

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    Quote Originally Posted by Dat Ei View Post
    AccurateRip is based on a database storing checksums for ripped Audio CDs (red book standard). Audio CDs have a resolution of 16bit per channel (2 channels ) and a sample rate of 44.1 kHz. So every other resolution or sample rate is not corresponding the Audio CD standard and can't be compared with AccurateRip checksums therefore.


    Dat Ei
    Quote Originally Posted by Spoon View Post
    It is not possible to enter the lead in time.

    There is no way of knowing if a track is present, they cannot be checked if the lengths are not correct.

    If the audio has changed from the CD source, then reconverting back to cd source will not give an accuraterip result, changing frequency and sometimes bit depth is a lossy process, the original 44KHz 16 bit track is lost.
    Great, thanks for your input both - do either of you know why I'm getting a "not present in AccurateRip" message when I've ripped with iTunes in the correct CD format (16 bit .wav files at 44.1kHZ)? I've double checked with a CD I ripped using dBpoweramp last week which had a high AccurateRip confidence, but when I rip with iTunes and check using PerfectTunes I get a "not present" result.

  8. #8
    Administrator
    Join Date
    Apr 2002
    Posts
    42,062

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    Because of the missing lead in time.

  9. #9
    dBpoweramp Guru
    Join Date
    Nov 2007
    Location
    Florida, USA
    Posts
    5,170

    Re: Checking Accuraterip retroactively does not work as should (OSX)

    If you own dbpoweramp you should not be ripping CDs with iTunes. iTunes is not known as a secure ripper.

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •