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Losless? Doesn't look like it.

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  • Neuromancer2791

    • Apr 2004
    • 6

    Losless? Doesn't look like it.

    I have an ape collection, but am pondering a wma9 conversion (because I bought a DiNovo keyboard and only Windows Player is 100% supported). Now here is a problem: it should be no danger to convert my entire collection from one losless (ape) to another losless (WMA9 losless) format. But if I convert to wma9 and back there is a difference in size! :(

    Original file (APE with APEv2 tag): 29,6 MB (31.075.840 bytes)
    Converted file (WMA9): 29,8 MB (31.266.816 bytes)
    Converted back to APE: 29,6 MB (31.082.496 bytes)

    Where exactly did 6.656 bytes come from?

    If you make more following convertions to the same file (to ape and back) size remains constant.

    Any explanations?
  • WavPack Man

    #2
    Re: Losless? Doesn't look like it.

    Originally posted by Neuromancer2791
    I have an ape collection, but am pondering a wma9 conversion (because I bought a DiNovo keyboard and only Windows Player is 100% supported). Now here is a problem: it should be no danger to convert my entire collection from one losless (ape) to another losless (WMA9 losless) format. But if I convert to wma9 and back there is a difference in size! :(

    Original file (APE with APEv2 tag): 29,6 MB (31.075.840 bytes)
    Converted file (WMA9): 29,8 MB (31.266.816 bytes)
    Converted back to APE: 29,6 MB (31.082.496 bytes)

    Where exactly did 6.656 bytes come from?

    If you make more following convertions to the same file (to ape and back) size remains constant.

    Any explanations?
    i seen such problem too.
    three files 42.6mb, one 37.2mb - four files the same original and some conversions in lossless and back to wav.

    besides, what is version number of WavPack codec?
    i meen your v1.1 is not real version of WavPack, isn't it?

    Comment

    • Spoon
      Administrator
      • Apr 2002
      • 44773

      #3
      Re: Losless? Doesn't look like it.

      You can only check lossless codecs by Converting Ape to wave and WMA Lossless to wave then comparing.
      Spoon
      www.dbpoweramp.com

      Comment

      • Neuromancer2791

        • Apr 2004
        • 6

        #4
        Re: Losless? Doesn't look like it.

        Originally posted by Spoon
        You can only check lossless codecs by Converting Ape to wave and WMA Lossless to wave then comparing.
        True. And when converting back to wave the file is identical. But where does that difference in question come from?

        Comment

        • JahSun
          dBpoweramp Enthusiast

          • Nov 2003
          • 69

          #5
          Re: Lossless? Doesn't look like it.

          It could be a few things. Perhaps you encoded your Monkey's Audio stuff with an older encoder, and then re-encoded with a newer version? Actually, it doesn't matter. The only thing we care about is the sound. The few bytes here and there could be from different tagging setups, i.e. using both Ape v2 & ID3 tags or ID3v1 & ID3v3 etc. or god knows what.

          If you really care about having 100% exact copies, you can use the Md5 feature with most lossless codecs. It started with SHN, but it works on FLAC & I believe even APE. (Md5 summer is freeware) This, and other "checksum" features that exist for ZIP & RAR files, creates small files (.md5) which can be stored with the compressed audio and checked against the file for errors, corruption, or bad encoding.

          The funny thing with lossless codecs is that they can produce different file sizes within the same codec based on the level of compression. In theory, the higher compression should take longer to encode, and leave you with a smaller file which will still decompress into the original wave file... However, my experience (and there are a few threads about this) shows that this is not always so. Despite taking longer to encode, high settings on FLAC and APE tend to produce similar sized files as the mid range settings... sometimes even bigger! This seems counter-intuitive, but I've played with it enough to satisfy myself that it is indeed true. It would seem that you should just set your lossless on the highest compression mode and forget about it, but currently the standard or medium settings tend to produce the best results...

          go figure:rolleyes:

          Comment

          • Spoon
            Administrator
            • Apr 2002
            • 44773

            #6
            Re: Lossless? Doesn't look like it.

            I am sure WMA have certain encoding serial numbers, unique to each encoding.
            Spoon
            www.dbpoweramp.com

            Comment

            • Neuromancer2791

              • Apr 2004
              • 6

              #7
              Re: Losless? Doesn't look like it.

              Thanks to all. By the way I have decided to stick with apes for time being, at least until DBpowerAMP supports APEv2 tags. Not for long it looks - because Matt Ashland is promising 3.99: "MAC 3.99 should be out before too long with compression improvements, so it may be worth the wait." But he wrote that in late january... (http://yabb.jriver.com/interact/inde...0093#msg130093)

              Comment

              • Spoon
                Administrator
                • Apr 2002
                • 44773

                #8
                Re: Losless? Doesn't look like it.

                There is an APE codec in 'Beta' of this forum that supports APEv2.
                Spoon
                www.dbpoweramp.com

                Comment

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