mp3: Different codecs/params -> Quality

Most people don't know much about mp3 encodings other than that there are different bitrates (e.g. 128kbps, 192kbps etc).

Every now and then I read comments about how bad mp3s sound in comparison to the CD ... but it highly depends on many things:
 

• How was the audio data extracted from the CD? Analog, Digital, Digital + Error Correction?
• Was volume normalizing done when ripping the CD?
  
• Which codec was used to create the mp3 files? Fraunhofer, Lame, Blade etc.
• Fixed bitrate / VBR?
• If VBR - which method?
  
• Joint Stereo?

I'll show you how I rip CDs:

http://sourceforge.net/projects/cdexos/

First of all - in settings -> CD Drive choose "Ripping Method = Paranoia, Full". This will ensure that the audio data will be extracted correctly even if the CD is badly scratched ... if the CD should be beyond repair, it will be shown during the extraction process.

In settings -> Encoder, choose the Lame encoder (default) and these settings:

• Version: MPEG 1
• Bitrate Min: 64kbps
• Bitrate Max: 320kbps
• Mode: J-stereo
• Quality: Very High Quality (q=0)
• VBR Method: VBR-MTRH
• VBR Quality: VBR 0

Have a try ... with these settings it takes a bit longer to create the mp3 files - but they sound much better, and their size is much smaller than that of 320kbps fixed bitrate files.




Edited by MikeEnRegalia - December 03 2006 at 09:45

I use Exact Audio Copy + LAME.

i'm the MASTER... 

i rip audio cds to .wav files with EAC (Exact Audio Copy), which, because of it's corrector, makes perfect copies of the audio information (beating the hell out of any other audio ripper). then i encode the tracks to loseless formats (my favourite is .flac) and backup them on dvds which are kept safe, and for my portable mp3player i make an .mp3 version of the album; usually at variable bitrate or at 190kbps. these proceedings keep my original audio cd out of danger because of little usage but i am also covered with the loseless backup for "just in case".

andu wrote: i'm the MASTER...  i rip audio cds to .wav files with EAC (Exact Audio Copy), which, because of it's corrector, makes perfect copies of the audio information (beating the hell out of any other audio ripper).

In fact most rippers make exact copies ... Windows Media Player, CDex, and many others. You just have to adjust the settings.

Can't think of any right now ... the best tip is to use a sane ripper program, either EAC or CDex. At least if you want to rip to mp3 it's really good to have access to the mp3 encoding parameters - they have a really big influence on the sound of the mp3s.

The two most important things to check are:

1. Does the ripper software really make exact digital copies of the CD? Ripping CDs to mp3 is always done in two steps: First extract the audio information from the CD "as is", then convert it into mp3. Some old computers still use analog extraction, which severely damages the quality of the audio files. Others use digital extraction, but no error detection/correction, and you might end up with clicks/pops in the files without being informed by the software, or it tries to interpolate the missing information which also degrades the quality.

2. Use proper settings for the mp3 encoder. Most of you (including me) prefer audio quality over file size reduction, and if you use rippers which don't give you access to all the settings you might want to choose 192kbps, it's a good compromise. But variable bitrate really sounds much, much better for certain files. Variable bitrate means that the encoder analyzes the signal and determines the complexity, and then chooses the appropriate bitrate for the different parts of the track (it may in fact choose different bandwidths for each mp3 frame - that's a fraction of a second).

I use bitrates from 64kpbs to 320kpbs, and this is really the best of both worlds ... tracks which don't contain much info (e.g. only limited frequency range, a lot of silence) result in small files, tracks with very complex info (many instruments at once, much drums/percussion/cymbals/distorted guitars (square waveforms) result in quite big files but in turn sound much better than 192kbps fixed bitrate files.

^ I'm glad you like it. Of course the files are also much bigger ... but the storage capacity of the mp3 players is always increasing, so it shouldn't be much of a problem.

I will try it after...how do the file sizes compare to say ripping to Windows Lossless? I got two files 450mb each when I ripped the 2 CD "Stars Die" (PT) the other day...

I won't listen to files that are less than 160kbps. You can really hear the difference all the way up to 192. After that, you have to have pretty high quality stereo equipment to hear differences.

I just standardise on 256KBps for MP3. There's plenty of room on my Walkman (20GB)

MikeEnRegalia wrote: In fact most rippers make exact copies ... Windows Media Player, CDex, and many others. You just have to adjust the settings.

yeah, they all say that...

anyway, i only use mp3 because of the mp3players... i wish there were OGGplayers or MusepackPlayers, but popularity brings the real bussiness so...