Q on MP3 Quality

Discussion in 'Windows Desktop Systems' started by WiredBrain, Dec 3, 2003.

  1. WiredBrain

    WiredBrain Guest

    2 questions on MP3 quality :

    1. If I convert a 128kbps MP3 file to WAV file before reconverting it back to MP3 file with 192kbps, will its quality be the same as a 192kbps MP3 file ripped straight away from the cd ?

    2. Comparison between 128kbps and 192kbps file, will we really hear the difference ?
     
  2. muzikool

    muzikool Act your wage. Political User

    1. Decompressing an MP3 and recompressing it at a higher bit rate will not give you better quality, but worse. Think of it this way: You reduced the quality of the WAV file when you compressed it to 128kbps, you can't take that same file and increase the quality. You need to rip the CD again and encode to 192kbps from that new file. By decompressing and recompressing the same file, you are reducing the quality of a file that has already had its quality reduced before.

    2. Absolutely. I don't encode into anything lower than 192kbps. If you have the disk space, I'd recommend 256kbps. I will admit that I'm somewhat of an audiophile, but still, I think that even the normal listener could tell a difference if they compared bitrates.
     
  3. vern

    vern Dominus Political User Folding Team

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    1. All I can say is ... garbage in, garbage out.

    2. If the source was of better quality than 192kbps, you should notice better sound quality with 192kbps over 128kbps.
     
  4. SPeedY_B

    SPeedY_B I may actually be insane.

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    What everyone else said really :)

    The first (compressed) format something is encoded to is what it will stay at, it wont magically de-compress back into it's original state.
    And 192 is much nicer than 128 :)
     
  5. dreamliner77

    dreamliner77 The Analog Kid

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    Noise is added (that you really can't hear) on the first encode. Re-encoding will only make the encoder try to encode that noise, which will make it audible.

    Suggestion: Use LAME with the command line --alt-preset standard

    Constant bitrate = varible quality
    Varible bitrate = constant quality
     
  6. lechtard

    lechtard Guest

    1: as everybody else said, compressing then decompressing, then compressing again is not good ...

    2: 192k or above (some use 256k or alt-preset-extreme) is true cd quality .. it's all based on preference .. but if you are going to make an MP3 cd then using 192 or higher is best. Remember though that the higher the bit rate the larger the file is ..
     
  7. WiredBrain

    WiredBrain Guest

    I'm using CDex 1.5.

    1. So, the normal audio cd I'm making from the MP3 will have a lower quality ?

    2. The recommended by you all is 192kbps or above. What's the most optimum and practical ?
     
  8. muzikool

    muzikool Act your wage. Political User

    1. If I'm understanding your question correctly, then yes, the cd you're making from the MP3 will have a lower quality than the original file.

    2. 320kbps is about the highest bit-rate you will see. I recommend 192 at the minimum, strongly recommend 256, and recommend 320 if you have plenty of disk space available.
     
  9. WiredBrain

    WiredBrain Guest

    Another 2 questions :

    1. Even if the MP3 files are at 320kbps, they'll still be of a lower quality than the original CD. Is this true ?

    2. I can only maintain the quality by using WAV format. Am I correct ?
     
  10. Xie

    Xie - geek - Subscribed User Folding Team

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    WAV format maintains a perfect copy but you could also use a compressed non-lossy version of the WAV file by converting it to something like SHN (or the many others out there).
     
  11. Xie

    Xie - geek - Subscribed User Folding Team

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    mp3 is a lossy format .. no matter what bitrate you are throwing out data to make an mp3 so yes it will be lower quality then cd :)
     
  12. muzikool

    muzikool Act your wage. Political User

    Because it's the highest MP3 bitrate, 320kbps will be the least noticeable reduction in quality. The loss of quality is worth it to those that want the small file size.
     
  13. WiredBrain

    WiredBrain Guest


    Can you tell me more about the other formats ?
     
  14. muzikool

    muzikool Act your wage. Political User

    Shorten (SHN) is a lossless compression format. In other words, you don't lose any quality when you convert from WAV --> SHN. The format compresses the WAV file, but not to a size as small as an MP3. While a normal length song can be compressed to around 4-5MB as an MP3, the same file would probably be 35-40MB as an SHN, and around 60MB as a WAV. These numbers aren't exact, I'm just using them to give you an idea concerning the difference in size. If quality is of the greatest importance, then compress with a lossless format. If space is most important, then encode to MP3 at a high bitrate.

    More SHN info and download:
    http://www.etree.org/shnutils/shorten/
     
  15. WiredBrain

    WiredBrain Guest

    Thanks for all the info.
     
  16. muzikool

    muzikool Act your wage. Political User

    Sure thing. :)
     
  17. dreamliner77

    dreamliner77 The Analog Kid

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    If you are gonna stick with mp3, try cdex using the lame .exe. This will allow you to use the command line "--alt-preset standard" This is a highly tuned setting. It used variable bitrate and will usually average less than 192kbps. It is almost always transparent (transparent= In blind listening tests, indistiguisable from the original cd. There is no such thing as cd quality as by definition only cd's can be cd quality)

    As for other file formats. For lossy encoding I highly recommend Musepack (.mpc)
    http://www.hydrogenaudio.org/index.php?showtopic=1927&

    For Lossless encoding most people choose Monkey's Audio or FLAC
    www.monkeysaudio.com
    http://flac.sourceforge.net/

    btw, Shorten isn't used much anymore except by trading groups.

    wavpack is also becoming popular because it combines lossless encoding with lossy encoding
     
  18. lechtard

    lechtard Guest

    Eac Does all that is mentioned also ...
     
  19. dreamliner77

    dreamliner77 The Analog Kid

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    I only said cdex because it was mentioned here before. I use EAC myself. And no, EAC doesn't do everything mentioned out of the box, but if you go to those sites and get the right codecs and stuff, it will
     
  20. WiredBrain

    WiredBrain Guest

    What is 'lossy encoding' and 'lame.exe' ?