Codec Testing

[TrueJournals]

DISCLAIMER: First of all, this is using my own build of rockbox on my iriver H10 20 GB. The only patch included that SHOULD affect audio codecs is the mpa_removed_iram.pat ch from http://www.rockbox.org/tracker/task/6705?histring=mpa. Second of all, I am NOT an audiophile. I would consider my ears... normal... if there is such a thing.

The song I am using is "Hold On" by Green Day on their CD Warning. It is 2:56 in length. All files were encoded straight from the CD using MediaMonkey3 Alpha 4.

The Sound Quality scale I'm using assumes that CBR - 128kbps - MP3 will be the lowest quality. All ratings are out of 5, and CBR - 128kbps - MP3 is automatically given a 1.

For comparison purposes, the iriver H10 has a PP5020 CPU that runs at 75 Megahertz. Anyway, on to the tests...

TrueJournals' H10 Audio Testing

FLAC:
  L0 - FLAC
    File size: 25.1 MB (26,326,270 bytes)
    Sound Quality: 4
    Decoding: 660.67% realtime
  L5 - FLAC
    File size: 23.7 MB (24,872,743 bytes)
    Sound Quality: 4
    Decoding: 473.45% realtime 
  L8 - FLAC
    File size: 23.6 MB (24,836,771 bytes)
    Sound Quality: 4
    Decoding: 386.14% realtime

OGG:
  Q4 - ~128kbps - OGG
    File size: 2.88 MB (3,025,123 bytes)
    Sound Quality: 2
    Decoding: 169.47% realtime
  Q7 - ~224kbps - OGG
    File size: 5.34 MB (5,605,922 bytes)
    Sound Quality: 3
    Decoding: 148.12% realtime
    NOTE: I think something went weird when encoding this one... so this test might not be accurate.  When I played it, I got a very weird noise at the very beginning...

MP3:
  CBR - 128kbps - MP3
    File size: 2.70 MB (2,832,512 bytes)
    Sound Quality: 1
    Decoding: 187.07% realtime
  CBR - 192kbps - MP3
    File Size: 4.05 MB (4,249,728 bytes)
    Sound Quality: 2 - Bass seemed stronger
    Decoding: 182.91% realtime
  ABR - 128kbps - MP3
    File Size: 2.58 MB (2,713,728 bytes)
    Sound Quality: 1
    Decoding: 187.07% realtime
  ABR - 192kbps - MP3
    File size: 3.93 MB (4,128,896 bytes)
    Sound Quality: 2 - Again, stronger bass
    Decoding: 182.83% realtime
  VBR - ~130kbps (V5) - MP3
    File size: 2.96 MB (3,113,088 bytes)
    Sound Quality: 2.5 - Seems a bit better...  but still not extroadinarily different than CBR
    Decoding: 185.05% realtime
  VBR - ~190kbps (V2) - MP3
    File size: 5.16 MB (5,415,040 bytes)
    Sound Quality: 3 - Bass better and a bit less overpowering
    Decoding: 176.95% realtime

WAV:
  WAV
    File size: 29.7 MB (31,211,242 bytes)
    Sound Quality: 5 - Sorry... I just had to...
    Decoding: File too large... would be over 1000% though.

So, there you have it... not even sure if FLAC really deserves the 4 it got for sound quality... oh well. What's the best format you ask me? Well, since I like to play games while listening to music... I would go for L5 FLAC. However, I also have 20 GB of space. Otherwise, I would just go to something like 128kbps. If there is a difference, it's small, and you might not even hear one. While I would love to distribute these files for you to test, I can't. I'll try making something that I can redistribute and hosting that somewhere for you who are eager to test.