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Verify that FLAC file is still an accurate rip a year later

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  • arohl
    • Jan 2021
    • 3

    Verify that FLAC file is still an accurate rip a year later

    Hi

    I am hoping to verify that my FLAC file is the same as it was when I ripped it a year ago (using XLD). From the log file of my RIP I know:

    CRC32 hash : FA5DDF0A
    CRC32 hash (skip zero) : 5E8732E4
    AccurateRip v1 signature : 8C0BCA19
    AccurateRip v2 signature : E6EE3E8E

    Is it possible to calculate any of these from my FLAC to ensure that no bitrot has set in?

    Many thanks

    Andrew
  • garym
    dBpoweramp Guru
    • Nov 2007
    • 5773

    #2
    Re: Verify that FLAC file is still an accurate rip a year later

    Originally posted by arohl
    Hi

    I am hoping to verify that my FLAC file is the same as it was when I ripped it a year ago (using XLD). From the log file of my RIP I know:

    CRC32 hash : FA5DDF0A
    CRC32 hash (skip zero) : 5E8732E4
    AccurateRip v1 signature : 8C0BCA19
    AccurateRip v2 signature : E6EE3E8E

    Is it possible to calculate any of these from my FLAC to ensure that no bitrot has set in?

    Many thanks

    Andrew
    Edit: of course to make sure the FLAC file is not corrupted, you can simply use dbpa CONVERTER and "convert to" [TEST CONVERSION]

    yes, the dbpa related program PerfectTunes can do an AccurateRip database match check post-ripping. That's the main reason I purchased PerfectTunes.
    https://www.dbpoweramp.com/perfecttunes.htm

    Comment

    • arohl
      • Jan 2021
      • 3

      #3
      Re: Verify that FLAC file is still an accurate rip a year later

      Originally posted by garym
      Edit: of course to make sure the FLAC file is not corrupted, you can simply use dbpa CONVERTER and "convert to" [TEST CONVERSION]

      yes, the dbpa related program PerfectTunes can do an AccurateRip database match check post-ripping. That's the main reason I purchased PerfectTunes.
      https://www.dbpoweramp.com/perfecttunes.htm

      I was hoping to write some code to do it myself :-) I am not sure what file the CRC32 checksum has been done on - obviously not the flac file - do you know?

      Many thanks

      Andrew

      Comment

      • Spoon
        Administrator
        • Apr 2002
        • 44098

        #4
        Re: Verify that FLAC file is still an accurate rip a year later

        Flac internally has an MD5 hash of the audio, this is compared each time FLAC is decoded in dBpoweramp, any miss-match and dBpoweramp would inform you. All CRCs are on the decoded audio data.
        Spoon
        www.dbpoweramp.com

        Comment

        • garym
          dBpoweramp Guru
          • Nov 2007
          • 5773

          #5
          Re: Verify that FLAC file is still an accurate rip a year later

          Originally posted by arohl
          I was hoping to write some code to do it myself :-) I am not sure what file the CRC32 checksum has been done on - obviously not the flac file - do you know?

          Many thanks

          Andrew

          when you convert a FLAC to [TEST CONVERSION] it is decoding the FLAC file and comparing the embedded checksum with the calculated checksum. So you know the FLAC file is the same as originally encoded. And this can be done in an automatic batch. After moving my collection to a new backup drive, I often run batch convert to [TEST CONVERSION] on the library on the new drive to make sure nothing went wrong in the transfer. This seems to easily do what you desire with only a couple of mouse clicks, so not sure of the reason to write code to do the same thing.

          Comment

          • arohl
            • Jan 2021
            • 3

            #6
            Re: Verify that FLAC file is still an accurate rip a year later

            Many thanks both - I have learned something about the flac format now! I can simply use flac --test on all my files.

            Andrew

            Comment

            • garym
              dBpoweramp Guru
              • Nov 2007
              • 5773

              #7
              Re: Verify that FLAC file is still an accurate rip a year later

              Originally posted by arohl
              Many thanks both - I have learned something about the flac format now! I can simply use flac --test on all my files.

              Andrew
              And this built in ability to do the checksum test is one of the most important aspects of FLAC. I often have to try to explain this to people who think using WAV or AIFF format is "better" (it's not for any sound quality reason by the way). They say, "disk space is cheap, so why not use WAV/AIFF?" But when I point out that I can confirm with a few mouse clicks in a batch manner whether any of my 116,000 flac files are corrupted, but with WAV files, one would have to check each file one at a time, this gives them pause at least.

              Comment

              • Johnnyb
                • Jun 2022
                • 43

                #8
                Re: Verify that FLAC file is still an accurate rip a year later

                Hi! How do I use batch converter to do a test conversion? I have almost 1T of flac files to check. Is batch converter the way to go? I have reviewed the menus and the help files, but can&*8217;t figure out how to do it. Thanks
                Last edited by Johnnyb; March 05, 2023, 07:20 PM.

                Comment

                • Spoon
                  Administrator
                  • Apr 2002
                  • 44098

                  #9
                  Re: Verify that FLAC file is still an accurate rip a year later

                  Open batch converter, click to select the root music folder, click Convert, choose Test Conversion as the encoder, and convert, no error = all ok.
                  Spoon
                  www.dbpoweramp.com

                  Comment

                  • Johnnyb
                    • Jun 2022
                    • 43

                    #10
                    Re: Verify that FLAC file is still an accurate rip a year later

                    Thanks so much, Spoon. I feel like a real dummy when I can&*8217;t find this stuff. You all are so helpful. Cool. So I can just run a check on all of my files once I get them moved. Do you think I need to run Accuraterip in Perfect Tunes as well? Or is that overkill?

                    Comment

                    • garym
                      dBpoweramp Guru
                      • Nov 2007
                      • 5773

                      #11
                      Re: Verify that FLAC file is still an accurate rip a year later

                      Originally posted by Johnnyb
                      Thanks so much, Spoon. I feel like a real dummy when I can&*8217;t find this stuff. You all are so helpful. Cool. So I can just run a check on all of my files once I get them moved. Do you think I need to run Accuraterip in Perfect Tunes as well? Or is that overkill?
                      Can't hurt to run accuraterip in Ptunes. Not really needed if TEST CONVERSION didn't report an error. Note that with TEST CONVERSION, "no error" really means it just ends and returns to your screen with the selected file list. It doesn't say NO ERROR. It is only if there is an actual error that you will get a popup screen telling you that there was an error.

                      Comment

                      • Johnnyb
                        • Jun 2022
                        • 43

                        #12
                        Re: Verify that FLAC file is still an accurate rip a year later

                        Thanks Gary. Now I just have to figure out the best way to get the 1T of music onto my external drive from the internal hard drive. Does anyone know of any software that would make that easier or more secure? Then I have to set up my backups &*8230;

                        Comment

                        • garym
                          dBpoweramp Guru
                          • Nov 2007
                          • 5773

                          #13
                          Re: Verify that FLAC file is still an accurate rip a year later

                          Originally posted by Johnnyb
                          Thanks Gary. Now I just have to figure out the best way to get the 1T of music onto my external drive from the internal hard drive. Does anyone know of any software that would make that easier or more secure? Then I have to set up my backups &*8230;
                          easy, assuming the external drive is a USB drive, just plug the external drive into your PC or Mac and select the top directory of your internal drive music files, select copy, then paste to your external drive. Windows and Mac file programs have built in error checking, etc. to detect any problems. And then just to be sure nothing odd happened, after you transfer to the external drive run TEST CONVERSION on all those newly copied files. This will confirm that nothing got corrupted.

                          For incremental backup I use (for windows), a program called freefilesync. Does a nice job of keeping my backup libraries synched with main library (and it is efficient, because it only addresses changed or new files).

                          Comment

                          • Dat Ei
                            dBpoweramp Guru
                            • Feb 2014
                            • 1754

                            #14
                            Re: Verify that FLAC file is still an accurate rip a year later

                            For a Windows environment I would recommend the use of robocopy, a very capable Windows built in tool. I use it to synchronize my music files to several storages.

                            Dat Ei

                            Comment

                            • Johnnyb
                              • Jun 2022
                              • 43

                              #15
                              Re: Verify that FLAC file is still an accurate rip a year later

                              Thanks guys! I&*8217;m going to use the largest USB SSD drive I can afford. My digital library is growing exponentially!

                              I&*8217;m in a Mac environment, BTW. So, I&*8217;ll look for other software options. I know they are out there.

                              Comment

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