Monday, December 3, 2007

The Value of the .Mp3

Now, In all of this, I certainly do not mean to demean the value of the .Mp3 file format, or any of its cousins, brothers, or sisters. For those of you for whom these posts are a revelation (if anyone currently knows of this blog at all, hahaha), I urge you not to re-purchase thousands of dollars worth of .Mp3 files on CDs and cause yourself financial trouble. I have no trouble listening to .Mp3's, myself. From now on I will buy the CDs, but for the .Mp3 and .AAC files that I currently own from iTunes or Rhapsody, I will not go out and waste good money that was spent on buying high quality digital files by buying the same songs on CDs, excepting a select few, which I would really like to have in lossless.

.Mp3's and .AAC's, in the proper encoding, such as iTunes or Rhapsody, are excellent. I would have no problem purchasing songs that I could not get on CD, or needed very quickly, from iTunes or Rhapsody, and continuing to listen to them. The quality is superb. Do not be afraid to continue purchasing in .mp3 format if it is really not too large of an issue for you. Their encoding is good, and they are designed to make you think that nothing is different.

One great advantage is that all songs are now widely available to everyone, whether they are popular or obscure. It is an interesting fact that Baroque, Classical, and Romantic music, all put under the broad and general term, "Classical," have benefited most from online purchasing, more than any other genre, in terms of circulation, as well as in, I believe so, at least, profits. They offer themselves as an excellent tool to people who prefer having lossless audio as well. One can, "test the waters," online, and then purchase the CD and rip to lossless later.

The .Mp3 is undoubtedly powerful, and I certainly see no decline in its popularity in the near future, unless it is in favor of a better lossy format, such as the .AAC file format.

However, for true study and listening, lossless and raw formats will always be superior to the .Mp3, .AAC, or any other lossy format.

On the Ease and Availability of Lossless Sound Files

I recently posted a comment on a post by a good friend of mine at Maria's Music. He raised an excellent point about the value of actually owning a physical CD. You should read his post here. I've already discussed on this blog the value of raw and lossless audio, but what I want to dive a little deeper into is the ease and availability of using lossless sound files.

The main reasons for the invention of the .mp3 and other lossy codecs were hard drive space conservation and faster internet downloads. Raw .wav files would take hours to download on 56k dial up connections. I remember back when the .mp3 was truly popularized with the rise of Napster in 1999. Our family owned a desktop which had a 10GB hard drive, which was considered good for that time. I now run a Macbook Pro with a 200GB hard drive, and that is considered moderately large today.

Space is no longer an issue. I recently purchased a 500GB external hard drive, which runs extremely well, for $100. I will not even come close to filling it for a very long time. A 500GB hard drive can hold approximately 1,667 CDs in lossless format; not songs, but CDs. One could hold their entire family's CD collection, and probably that of a neighbor or two on a hard drive of this size in full, lush, and clear lossless format. A somewhat outdated rule of thumb for buying storage was that if one was buying at a rate of $1 per GB, they were buying for a good price. I must admit that I purchased mine during a black Friday sale, but my father recently purchased one (and a better model at that) for $134. Storage is cheap and available, and most will not need 500GB. Most often, depending on the size of the CD collection, a 200GB HD or 350GB HD will be more than enough, selling for under $100.

The iPod classic can now hold either 80GB or 160GB of songs or other media files, depending on the model. That is enough space for (rough math) 267 CDs in Apple Lossless format on the 80GB model, or for 534 CDs in Apple Lossless format on the 160GB model. I believe that very few people personally own 534 CDs, much less even 100 CDs, and that is the space on a portable player!

Internet connection speed is no longer a problem either. Apple either has or will soon implement a service where one can pay a little extra and buy songs in lossless format. Most connections are either cable or DSL at this point, with speeds ranging, on average, from 1500k to 3000k.

One is now able to enjoy full quality media, safely secure and store it, and transfer it (legally with purchase) with great ease.

Wednesday, November 28, 2007

Sister Blog, Sonare Coeli

Hello everyone,
For everyone who came to this blog first, my primary blog is Sonare Coeli. There I discuss the nature of music and how it relates to our Lord and Savior. My primary goal there, and now here, is to find the best possible way to musically express praise to Our God. I hope you enjoy reading both of these blogs and gain something useful from them.

May God bless you and keep you!

Lossless Audio

I needed to find a solution for my mammoth library of .aiffs. I came upon, "lossless audio compression," and found my answer. Lossless audio compression works essentially like a .zip file. When a file is zipped, it is compressed, and when it is unzipped, it is uncompressed. No data is ever removed. I do not know how the actual processes work, but this is the general concept.

Lossless audio compression works in the same way. It will take a raw .wav file, and compress it to half its size WITHOUT removing any data at all. The files are still large, but much, much more manageable. In addition to that, you now have full CD quality sound files in their original, unaltered form. If one would like more proof, notice the difference between listening to a CD and listening to an .mp3. Simply sit and listen. You will be able to tell a larger difference than you would have thought possible.

I read about many different methods and file formats, including Monkey's Audio (.ape files) and Free Lossless Audio Codec (.flac files), but eventually ended up going with Apple Lossless Format. This is where true audiophiles will pick nits. However, all of these files are lossless, as they say, and will give you the same full quality. Here are the reasons I chose Apple Lossless:

- iTunes, Windows Media Player, Rhapsody (to the best of my knowledge), and Real Player (to the best of my knowledge), will not play .ape, .flac, or many other lossless formats.

- Apple Lossless can be played in iTunes on Windows and Mac.

- I wanted all of my music organized in once place, and on a Mac, iTunes is best for that.

So, then began the process of finding all of my CDs and ripping them into iTunes as Apple Lossless files. As I said before, a file that is compressed in an .mp3 like way cannot be converted upwards. You can make a .wav out of an .mp3, but it will only contain as much sound data as the .mp3, but expanded. So, one will end up with a lemon of a file; a .wav that is the same quality as an .mp3, but ten times as large (or more). The data that was selected for deletion is now gone and the data that was selected for editing is now irrevocably changed. One must re-rip the files from the original CD.

I've gone through about thirty CDs as of right now. It is actually a very easy process, and the result is wonderful, lush, full quality audio.

File Conversion Troubles

I recently switched to Mac, and unexpectedly, iTunes and Mac OS X abhored the .wma file format (made by Microsoft), which most of my sound files were ripped as. Take the last statement with a grain of salt, it is a harmless final jab while I switch to a new operating system. However, iTunes would not add my .wmas to the library, nor play them. There were alternatives, but they were inefficient, and for a reason. Apple does not want Windows files to play, and Windows does not want Apple files to play (until the recent years).

So, in my struggle to find a solution, I turned to conversion of my audio files. I downloaded an excellent program called Switch, which will convert between many popular music file formats, for Windows and Mac. I converted my entire collection to the .aac format, which I may speak on later. Basically, an .aac file is a better version of an .mp3. It was called the, "successor to the .mp3," by the creator of the .mp3 file format. All that you and I need to know is that is handles the psycho-acoustic processes better and more accurately, while giving the file a much reduced size. I set the encoding options at 256 kbps CBR, just so that there would be no chance of loss with my 192 kbps CBR encoded .wma files. After the conversion I tested the results. I had found a slightly tedious plugin for Quicktime which would play my .wmas on a Mac, but it did not support a playlist or library, and could only have one file open and ready to play at a time. I compared the .wma in Quicktime to the .aac equivalent of the same music file in iTunes. They were drastically different.

The .aac was, "crisper," but lacked the mid-range and low-range frequencies that the .wma was putting out. The type of crispness was not one that was desirable by my standards either. I need to hear my mid-range and low end, all music is lost without it (I'm a bassist ;) ). On a more serious note, the low end was in fact severely reduced. I cannot say for sure whether it was a difference in the two players, or the two files. Both players, as far as I could tell, were set to a flat EQ, so I am led to believe it was a difference in the actual files.

I then took a drastic route. I converted all of my .wmas to .aiffs. .aiff files are the same as .wavs, they are raw sound data, and include ALL things that were recorded. This ensured that there would be no loss in quality. However, the file format was huge in terms of file size. It was true overkill. While the format was that of a raw sound file, it can only take as much sound data as its given. Once a file is turned into an .mp3 .wma or .aac, the sound data that was removed is now gone forever from those files, and cannot be returned by upwards conversion. So, essentially I had a library full of . aiff files that sounded like 192 kbps .wma files. This would not do, considering the heavy demands on file storage. This led me to explore lossless audio.

The Nature of .mp3s and Why It Is Best to Avoid Them

The nature of MP3 compression is not a secret, but I'm sure many people do not know exactly how it works. It is quite amazing how a 50 MB raw .wav file can be compressed to a tenth of its size or less and still sound the same to most ears. Raw .wav data is essentially that, raw sound waves recorded into a digital device. The digital representations of their real-world counterparts are exact replicas (well, technically they aren't entirely exact, but the difference is actually indiscernible to the human ear). These files include ALL sounds recorded, even those which are hard or impossible for a human ear to hear.

To reduce the enormous file size of this raw sound data, and MP3 employs a science called psycho-acoustics (essentially how the mind interprets sound) to remove or change these frequencies which are hard to hear. Basically, an MP3 encoder will begin by removing sounds which the average human ear cannot hear by themselves; generally sounds above 20,000 Hz, and below 20 Hz if I am not mistaken. Next comes the true psycho-acoustic processes. The encoder will then remove sound data from the file based upon models that it is programed with. Scientists have studied how the mind interprets sound, and have programmed these encoders to edit sound data, based on what the human ear can hear well, or not so well.

I will not delve into the depths of these processes, as I do not know enough myself, but one example would be that of a loud sound playing above a quiet sound. If the loud sound is loud enough, then human mind is said to focus on only the louder sound, and assume that the quieter sound it still playing underneath, until the loud sound ceases upon which time the ear then hears the quiet sound alone. An MP3 encoder would, in this situation, remove the sound data for the quieter sound while the louder sound was playing. The ear is said to interpret the quieter sound as continuing underneath, even if the data is not there. I think a diagram would help this explanation.


While .wav (raw sound data) data could be represented like this:

Louder Sound data: -------- -------- -------
Quieter sound data: ====================================



The .mp3 (edited sound data) rendering of the exact same
section of data would look like this in comparison:

Louder Sound data: -------- -------- -------
Quieter sound data: ======= ======


In this example, the quieter sound wave is represented by the === line, and the louder sound wave is represented by the --- line. In the .wav file representation above, the quieter sound continues, even while the louder sound is being played, as it would be in real-life. The human ear can still hear the quieter sound, but its focus is on the louder sound while it is playing. The .mp3 file representation takes advantage of this psycho-acoustic property. It removes the data for the quieter sound while the louder sound is playing, and leaves it alone elsewhere. The human ear is essentially "tricked" into thinking that it still hears the quieter sound. This applies at a very complex level.

I assume the next question by a reader might be, "Why can I hear the second guitar in my .mp3 file? The first guitar is much, much louder." The answer is that the sound an instrument produces is comprised of many sound waves that all come together to form its unique sound. This example speaks of two separate, pure frequencies. So, yes, you can still hear the second guitar under the first, but, in both instruments, you are not hearing all of the frequencies that would be there, because they are absent entirely in the .mp3 file.

Now obviously real-world applications of .mp3 files are not as black and white as this example. Obviously they sound very good, so the creators of the file format certainly knew what they were doing. That being said, it is an unnerving fact for people like me that I am not hearing every single bit of an instrument's tone quality and timbre when I am listening to an .mp3. The fact is that the difference between an .mp3 and a .wav file is actually very audible.

My first experience with this was with a comparison of a 128 kbps CBR .mp3 with a 192 kbps CBR .mp3. I knew the difference between 64 kbps and 128 kbps, but I thought after that it was near impossible to tell two files apart. I was ripping one of my own CDs and decided it would be best to go for "overkill" on quality, so I chose the 192 kbps format. In comparison with a similar 128 kbps, I could discern an audible difference. I bet that you, the reader, can as well; that is not great feat of the ear. Listen to the cymbals especially. They will sound more crystalline in lower quality files, and more clear in higher quality files. I invite you to test this. Take one song from a CD, and rip it in both 128 kbps and 192 kbps formats. If you cannot quite tell the difference, then start by comparing a 64 kbps and a 128 kbps file of the same song. I could not hear the difference of the 128 to 192 at first either. Even less discernible, but still very apparent to alert ears is the difference between a 192 kbps .mp3 and a 256 kbps .mp3. I began to rip everything at anywhere from 192 kbps to 320 kbps (I thought 320 was equal to CD quality at that time), but most commonly in the 192 kbps CBR .wma file format.

Now, after several years, what I was doing hit me. While 192 kbps is very high quality, it is still missing some of the sound data that would make a recording sound as close to the real setting as possible. There is a very audible difference between a raw sound file and a compressed .mp3, even of a bit rate as high as 192. So, now comes my plug for lossless audio file formats.

Tuesday, November 27, 2007

A New Audiophile

Hello everyone,
I hope for this to be the technological, and perhaps less formal, side of Sonare Coeli. Recently I've become aware of some interesting properties of digital audio. In this blog I'll discuss the nature of MP3s, why they should be avoided, and what should be sought when dealing with digital audio files.

Before I end this first post, I believe the term, "Audiophile," needs some explanation. Literally, a "Lover of Sound," this term refers to a person who strives at all measures to achieve the best possible quality of sound in whatever situation they may be involved in. These are the people that constantly adjust their home theatre surround sound system to get things just how they want them, and also the people who listen to raw .wav or .aiff files on their computer, for fear of losing quality in sound. I would consider myself only a second class audiophile, or maybe even third. I own good speakers, but not ridiculously-expensive Bose- engineered-to-perfection sound-of-the-gods speakers that some true audiophiles own. Once again, I have good speakers that are of excellent quality (and excellent price), and I think they sound wonderful. Now, for the real nuts and bolts.