Ripping your CD collection part 2 – building your library

In the first part of this series I discussed the history and  basic concepts of digital audio encoding. In this final part, I will explain the process of successfully ripping a CD collection to ensure optimal audio quality and portability.

Choosing the encoding format
So given the discussion in part one of this series, what format do you choose to encode all those hundreds of CDs in your collection? High bitrate MP3 would ensure compatibility but quality will not be perfect. FLAC will ensure no loss of quality but the files will only be playable on a small subset of players.

If you are an Apple domain user  you may want to consider the AAC (Advanced Audio Codec) or ALAC (Apple Lossless Audio Codec) formats which are supported by all Apple devices. Be aware though that your files will not be portable for playing outside the Apple domain (ie Windows, Linux etc).

It turns out EVERY format has these sorts of considerations so there is no one solution that fits all.

Faced with this dilemma and the considerable task of ripping my CD collection for the second time in five years, I chose a compromise solution. I ripped all my CDs in FLAC format. Once complete, I then coverted them to MP3 variable bit rate (VBR) v2  format (smallest files with good quality). I now maintain two digital music libraries:  my FLAC collection for archiving and high fidelity playback and an MP3 collection for playing in the car and on portable players. I share the MP3 library as read-only for the kids to use and to load on portable devices. I stream my FLAC files to my amplifier (via my XBOX 360) using Asset which conveniently converts the files back to the original uncompressed (PCM) format in real-time.

This “dual format” solution is not as elegant as I would have liked but does have many advantages:

  1. Storage. Disk storage on PCs is cheap so the cost storing a second compressed copy of my music collection is negligible.
  2. Quality. The quality of FLAC audio files cannot be appreciated through cheap computer speakers or headphones connected to a smartphone or iPad so MP3 format in these environments will suffice.
  3. Mobility. Storage on mobile devices is limited and expensive. Its therefore important to minimize file sizes to maximise the selection of music while mobile.
  4. Technology. Computing power and software allows FLAC files to be transcoded into any other audio format easily and quickly.
  5. Futureproofing. FLAC files can be used to recreate the original source CD audio files if needed – eg: if a better lossless format is developed or the original CDs are lost or stolen. This ensures I will never have to re-rip the CD collection again.

Folder and file naming
You will be creating one file per music track therefore if you have a substantial CD collection it is essential you come up with a good file and folder naming strategy that makes your tracks easy to find – and stick to it. Its much harder to reorganize thousands of files than to get it right when they are first created.

In my digital music library I use the following standard:

Music\Albums\<Artist>\<Album>\<track> <artist> - <track>.<type>
Music\Singles\<decade>\<artist> - <track>.<type>


Music\Albums\Dido\No Angel\06 Dido - Thank You.flac

Complete albums are stored in the Albums folder. Any singles or incomplete albums are stored in the Singles folder. I use the track number in the file name to ensure the files can always be played in the order they appeared on the album – even on systems that reply on file names rather than tags (eg: my car).

Ripping your first CD
The process of converting an audio CD to another digital format on a computer is colloquially known as “ripping”. In the Wintel domain, there are lots of really good free tools available to do this. I have tried Exact Audio Copy, MediaMonkey, Foobar2000, Fre:ac (formerly BonkEnc), and dbPowerAmp CD Ripper. They are all free, work with freedb and can all rip in FLAC format.

Exact Audio Copy (EAC) is the defacto standard for making high quality FLAC rips – mainly because it is so anal about being accurate. But the complexity of the user interface leaves a bit to be desired for a first time or novice user.

Fre:ac allows you to automate the ripping process to simply inserting the next CD to be ripped. At the completion of a rip, the CD will be ejected and it waits for the next. This is important if you have 100’s of CDs to rip.

dbPowerAmp cannot automate the process but does have the ability to rip in more than one format simultaneously. This is handy if you want to rip in FLAC and MP3 as I have chosen to do. It also allows for the album cover image to be added to the folder at time of ripping. Something the other tools do not support.

MediaMonkey and Foobar2000 are players that also support CD ripping. They are not dedicated rippers in their own right but do a good job of an adhoc rip now and then once the bulk ripping job has been complete.

I suggest you try a few sample rips with these tools before choosing the one that suits you best.

Album art
Once you have your freshly ripped digital music library you are going to want to add album covers so you can browse albums just like a physical collection. There are no standards in the storage and format of album covers each player does it differently. Some players want the art to be stored in the meta data for each file. Some expect to find a specially named file in the folder and others (like iTunes) just do their own thing.

I have found that storing album covers as 600×600 files named folder.jpg seems to work best for most applications. You can generally download covers from Google’s image database and edit/resize them with your favourite graphics editor.

Replay gain
Replay gain is a convention for normalising (making the relative  track volumes the same) digital audio tracks. Not all tracks have the same volume. More modern tracks are notably louder than older recordings. So shuffling between songs can result in varying track volumes – from inaudible to ear splitting. Most software players support replay gain where the relative track volume is stored in the meta data of the track and the volume of the track adjusted accordingly when played. The idea being that if all tracks use replay gain, they should all be played at a consistent volume – no matter when or how they were recorded. To work out the relative volume of a track, it must be examined for volume peaks. This can be time consuming so its best done once as part of the encoding process.

The process of changing digital audio formats (eg changing a FLAC encoded file to a MP3 encoded file) is known as transcoding. It is important to note that the quality of a track cannot be improved during the transcoding process even if the the bitrate is increased. A poor quality 128Kbps Mp3 track will continue to sound bad transcoded to  256Kbps AAC – or any other format. The only thing that happens in this transcoding process is the file gets bigger and the quality gets worse.

Its important therefore to only transcode from high quality to lower quality and never the other way. Bits cannot be created. Thats why its important to rip in the highest quality in the first place as any quality lost in the ripping process can never be reinstated. Lossless formats like FLAC – being the ultimate quality – means they are a perfect source for transcoding to any other format.

Transcoding is simply a process that converts a file back to its native format (eg wav) and then re-encodes it into the destination format.

Foobar2000 and MediaMonkey can be used to bulk transcode a FLAC library to MP3 VBR including album art and meta data.

I hope this series of articles has helped getting started ripping your CD collection and building your digital music library.

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