There is a well known book by Stephen Covey called The Seven Habits of Highly Effective People. In this book, he describes one of the principles as “Begin with the End in Mind.” He means to begin each day, task, or project with a clear vision of your desired destination. This is true in life and is applicable to the topic of this chapter. Before you begin mixing, you should have a clear vision of the end product and anticipate the technical considerations that might apply.
In the prior era of making records (these were actually made of vinyl and played on a device known as a “record player”), you had to take into consideration everything about a mix as it applied to the record and the radio, and very occasionally, the television set. By today’s terms, this was fairly straightforward. You might have checked the mix on large speakers, small speakers (usually Auratones, which were very small, simple, and unflattering), and in both mono and stereo formats. But that was about it. Those were the good old days.
In the digital era of today, things become a bit more complicated, and in this chapter, I will explore some of those issues. Sure, I’ll talk about stereo and mono, but there is also the issue of compression. And compression, it turns out, can mean two entirely different processes: audio compression (also called “brick-wall limiting”), which can be used to make a track sound louder, and file compression, a process that squeezes your file size down until it screams “enough already.”
Yes, the digital age is much more technical. You need to understand sample rates, bit depth, codecs, and file formats—some of which apply to audio and others that apply to video. This chapter explores these issues, but you need to keep one thing in mind. No matter how technical or “tweaky” you get with your tracks, always ask yourself if the music itself sounds good enough.
Question: When is good enough not good enough?
Answer: When you’re putting your whole reputation and chance for success into a three-minute music video that represents the best possible you.
There was a day when the phrase “That’s good enough” represented an adequate, acceptable level of professionalism on any given project. That time period ended in the Stone Age with the production of the very last iron spear. Today is another story. Today presents a no holds barred, no excuses, better-be-great-or-you-lose scenario.
There are reasons for this. Among them, you are working in a very, very competitive field. While you read this last sentence, it’s quite possible that 14 music videos were completed and posted on the Internet. (Okay, it’s possible—I didn’t say it was an absolute fact.) I may not have the statistics, but it’s a well-known fact that people in the creative arts are facing more competition than ever before, including in the fields of music, video, music videos, film, television graphic arts, ballet—you name it.
You, as well as your competitors, have access to technology that allows you to create professional output. It’s a “no-excuses” world out there, with lots of people scrambling to make their dreams come true.
If your final product doesn’t absolutely floor you—and make you convinced that it cannot be beat—then it’s not good enough.
Think of it this way: In the “old days,” you could make a demo of a song and use that as your “calling card.” A demo implied, “When I get a real studio and a real budget, I can make the real thing.” For the most part, people are not making demos anymore—they’re making masters.
You can hear talk among musicians and engineers in the studio environment, some of which is relevant to the concept of “good enough.” The following table shows just a few examples.
One of the technicalities that didn’t apply to mixing in “the old days” is the topic of compression. You will see that compression can mean a couple of processes—using compression (or limiting) to increase the perceived loudness of a track, and the other type of compression—using specific algorithms to reduce file size while hopefully maintaining a decent amount of quality. I’d like to address the first type of compression first.
One of the trends in today’s music is making the tracks sound as loud as possible. By the use of “maximizers” or “brick-wall limiters” (see Figure 2.1), engineers and musicians work to get the apparent level so high that it seems louder than any other track out there. Indeed, it may “sound louder,” but at what price? The price can be the loss of dynamic range. Because the lower-level audio is maximized to sound louder, the louder sections cannot exceed a certain threshold without distorting. (For argument’s sake, say 0 dB.) So, if done properly, the audio hits a ceiling that may not contain distortion; however, the overall sound seems “squashed.” The apparent difference between the lower-level sounds and the louder ones is reduced to the point where dynamic range is severely compromised.
The sad truth, however, is that almost everyone is using this mastering technique to keep up with the rat race for producing louder tracks. So what do you do? The best answer is to find a compromise—a middle-of-the-road that doesn’t squash the track too much but is boosted enough to sound loud, even if not as loud as the loudest tracks out there.
This may take some experimentation, but the results can be worth it. And because I’m talking about music videos here, getting the right balance is critical so that you sound, at a minimum, competitive. I will caution, however, that if your music is orchestral in nature, it is best to give it the most natural dynamic range possible, with only the loudest peaks hitting the highest threshold before distortion. Nothing sounds worse than strings and horns squashed to only one level with no variations in dynamics.
Although brick-wall limiting may not have been a consideration in the making of records, the issues of mixing for stereo and mono in the digital age can sometimes apply. In “ancient” times, when studios were producing records for radio or music videos for television, the topic of creating a stereo mix along with a mono-compatible mix came up often. You didn’t know if your music would be heard on an old record player, CD player, or television set that didn’t have stereo sound (although, admittedly, it would have been difficult to find CDs that were being played on mono systems). So, because of issues like phasing—or the stereo channels getting out of phase—many steps were taken to ensure that the final stereo mix sounded good on a mono system. Some simply played the stereo mix on a mono system to check it out, while others used mixing boards that had a “mono switch,” allowing them to hear a sum of the left and right channels to ensure that the audio was up to par.
While you might choose to take these extra steps, it is fairly unlikely that you would have to. If your music video is going to be posted on the Internet, the playback systems are likely to be PC speakers hooked up to the computer’s audio output, which is stereo. If it is played on a Mac, it has stereo audio outputs as well as internal stereo speakers. The plain fact is that for the most part, mono has gone the way of a dinosaur. If you are going to spend extra work cycles on your final mix, focus your energy on something else, such as sample rates and file formats.
A wide variety of sample rates are used in today’s audio recordings, and it can sometimes be confusing to know which ones to use (let alone understand what sample rates actually mean). Briefly, a sample rate refers to the number of “snapshots” that are taken of an audio signal every second. Higher sample rates provide more detail in an audio signal. Common sample rates are 44.1 kHz, popularized by the compact disc, and 48 kHz, popularized by the DAT (digital audio recorder). In recent years, higher sample rates such as 96 kHz and 192 kHz have entered the picture, spurred on by the advent of the audio DVD and the never-ending quest to have higher quality sound. Most modern interfaces that convert audio from the analog world into a computer use a variety of sample rates, including some of the higher ones.
Another aspect of sound quality is determined by bit depth. Higher bit depths yield higher audio resolution in terms of dynamic range. Low-quality audio, such as appeared in the first computer games on the PC, usually had a bit depth of eight bits. CD audio is 16-bit. And like the higher sampling rates that provide high-quality audio, higher bit rates contribute to better audio and have appeared in the form of 24-bit resolution. That’s why you may see audio specs today that advertise 96 kHz/24-bit resolution and other high-end sample rates and bit depths.
When all is said and done, however, CDs can play back only in 44.1 kHz/16-bit resolution, and the audio tracks for video play back at 48 kHz/16-bit. So why all the fuss about using higher rates for recording if it’s going to be down-sampled when you’re done? The reasoning is that using higher sample and bit rates will yield a better audio recording, even if it has to be down-sampled at the end of the process.
What you decide to use in your recording is ultimately up to you. You might try auditioning DVD audio discs and other audio programs that play back at higher rates to see if you can hear the difference. Some people swear by it, meaning they can hear much better quality in these formats. Others attest that there is no audible difference.
The bottom line is that you should never go below the lowest and most common spec for video, which is 48 kHz/16-bit.
Never before in the history of mankind has there been anything so gloriously confusing as audio and video file formats, bit depths, and compression algorithms. Okay, maybe there are things more confusing somewhere (such as the credit crisis that began in the fall of 2008, for example). But, for certain, these bits of technology are in the top ten. To make things even more interesting, there are codecs, file types, and container formats—some of which are used interchangeably or simultaneously to mean the same thing, or even different things. Confused yet?
You don’t need to become an expert in these topics—unless you want to, of course—but you do need to have enough of an understanding to make the right choices at the right time for your audio and video production needs. I hope the following discussion will give you enough ammunition to put up a good fight in the format jungle.
What, you might ask, is a codec, and what’s its purpose? First, I discuss its purpose. Because of the large size of audio and video files, compression is necessary, and you reduce their size by use of a codec. The compression side or coding aspect of the term is the co of codec, whereas the decompression or decoding side of the process is the dec. Put them together and you have a codec. Using compression, by means of a codec, you make video manageable in terms of its file size. This process also optimizes a file’s bandwidth so that it can be streamed efficiently over the Internet.
A variety of codecs have certain advantages or disadvantages for audio and video files, depending on the specific applications of the digital media file. There are also two major categories of codec—lossy and lossless.
Lossy codecs reduce the actual size of the data in order to achieve compression while utilizing specific algorithms to give the impression that all of the data is there. To put it another way, a lossy codec shrinks the file size in a sneaky way so that no one (hopefully) will notice it.
A lossless codec compresses a file without discarding any data. The choice of what codec to use in a given situation usually depends on whether a small file size is of great importance (in which case, a lossy codec is used) or whether quality is of paramount importance (in which case, a lossless codec is the better choice).
One source of confusion when attempting to understand codecs is that some of them are actually a specific type of algorithm for compressing/decompressing a file and some are file format. To make life more interesting, some of them are both.
Codecs are discussed in more detail in Chapter 10, “Making Your Video Internet-Ready,” especially as they apply to putting your video online.
Using compression accomplishes two main goals: It reduces the file size of the video and compresses it for smooth streaming on the Internet. Both of these tasks are necessary for the production of music videos for the Internet.
The multitude of file formats available for audio has been the result of many years of competition between different computer platforms (Apple and Microsoft come to mind), as well as surprising yet effective innovations, such as the ubiquitous MP3 format.
If I were to discuss every single file format that has emerged in the last decade due to the transition to digital media, I would have to write a separate book on the topic (and frankly, I’d rather not). So, I’ll keep the discussion focused on the file formats that relate to the making of music videos.
Here are the most common audio file formats that are of interest to you:
AAC—Advanced Audio Coding: Audio format popularized by Apple’s iTunes that uses sophisticated compression algorithms designed to improve the MP3 format. Files usually have an extension of .mp4 (because it is a version of the MPEG-4 standard).
AIFF—Audio Interchange File Format: Common audio format for both Mac and Windows, although it is much more common on the Mac.
AU—Audio Units: A system-level architecture for audio plug-ins used by Apple’s Core Audio in the Mac operating system.
WAV: The original audio file format from Microsoft.
MP3—MPEG-1, Audio Level 3: A popular audio file format that uses a great deal of compression to make files roughly one-tenth of their original size. MP3 uses effective compression algorithms that eliminate or reduce sound outside the range of human hearing.
WMA—Windows Media Audio: An audio codec and file format from Microsoft that is their answer to MP3.
The variety of video formats has also been the result of computer platform wars. Added to that, several innovations have come from the video and film industries. Listed here are the most common and relevant to the process of making music videos:
AVI—Audio/Video Interleaved: One of the first video file formats. It was developed by Microsoft.
DivX: A video codec often used for downloading video from the Internet. It is based on MPEG-4 and uses AVI as its container format. (I told you this topic is confusing!)
WMV—Windows Media Video: Microsoft’s current video file format.
QT—QuickTime: As close to a standard as you can get that works on both the Mac and the Windows operating systems.
MPEG-4: A container format for audio and video. If both audio and video are present, the filename .mp4 will be present. If it is audio only, the file has an .m4a extension.
H.264: An advancement of MPEG-4 that provides high-quality video frames up to four times the original size.
As of this writing, H.264 is one of the most popular formats along with Apple’s QuickTime. Very often, a QuickTime movie (of which you will be making many) is reduced in size to the H.264 format, which most often uses AAC for the audio portion of your program. During the compression process, you will have options for choosing what kind of file format, file size, screen size, and audio compression method you want to use.
Try to familiarize yourself with the file formats mentioned in this section. However, if you are in a hurry (who isn’t?) and want to cut to the chase, the following section can be used as a reliable “one-stop” guideline for which file formats and compression methods to use.
If you study codecs, file formats, container formats, and fractals long enough, rest assured you will get a migraine headache. So, to simplify this topic, here are some helpful hints about compressing video:
Watch and rewatch your video before compressing it. The compression process can take a long time and the last thing you want is to find a couple of small errors in the original video that require you to start over. Watch, rewatch, compress.
Use QuickTime to compress your video. More specifically, use QuickTime Pro, which is the professional version that contains all of the tools you need for compression and is available for both the Mac operating system and for Windows. If you already have the regular version of QuickTime, you already have QuickTime Pro, because when you purchase the Pro version, you’re given a code that unlocks it.
Use H.264 for compression. Set the data rate somewhere between 500 Kbps (kilobytes per second) and 7500 Kbps, keeping in mind that the larger numbers also mean larger file sizes. With compression comes experimentation—it’s the law.
If your aspect ratio is standard (4 × 3), then your screen dimensions should be 640 × 480 (or an exact equivalent of that). If your aspect ratio is widescreen at 16 × 9, then choose 720 by a number from 405 to 480 (experiment with this as your mileage may vary). Finally, if you’re working with HD, then you’re probably looking at 1280 × 720. Whatever the case, especially with letterbox format, make sure you select Preserve Aspect Ratio using either letterbox or crop.
Make sure you select Optimize for Streaming. This is important for posting video on the Internet. With this setting, viewers can start watching the video while it’s still downloading.
For audio, use the AAC codec. Set the bit rate no lower than 128 Kbps and ideally 160 or 192 Kbps.
Compression can be a daunting task, even for professionals in the business. But it is a critical process that can help to ensure that your video looks and sounds its best. When it comes to music videos, that’s very, very important.
See Chapter 10 for additional details on compression and file formats that are used to make your music video Internet-ready.