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Digital Recording Formats

Cecep SWP — Sun, 20 Sep 2009 07:15:29 +0000

Betacam SX format released by Sony Corporation in 1996. It’s a component digital format that has a sampling ratio of 4:2:2 and a 10 :1 MPEG 2 compression ratio. The recording is done on a 1/2-inch metal-particle videotape enclosed within a cassette. The format supports up to four digital audio tracks plus a time code. The maximum recording time for Betacam SX is 184 minutes, and the tape moves through the transport at a play speed of 59.6 millimeters/sec, or 2.3 inches/sec.

D-1 {4:2:2} component digital format was introduced in 1986 and has since become the industry standard for uncompressed digital video recording. The recording is made on a 3/4-inch-wide videotape enclosed within a cassette. The maximum recording time for the format is 90 minutes. The format supports up to four digital audio channels plus a cue track. For color correction of standard definition material, the D-1 format is by far the best format to use because it represents the highest quality available and has no video compression.

D-2 format is a composite digital format that records information onto a 3/4-inch-wide videotape enclosed within a cassette and runs at a speed of 5.185 inches/sec, or 131.7 millimeters/sec. The D-2 format has four digital audio channels and supports a maximum recording time of 126 minutes.

D-3 format is a composite digital format developed by the NHK in 1991. It records the information onto a 1/2-inch-wide videotape enclosed within a cassette at a speed of 3.28 inches/sec, or 83.88 millimeters/sec. It has a maximum recording time of 246 minutes. It supports up to four channels of digital audio and has one channel allocated for the time code. It’s a format that is widely used throughout the broadcast industry.

D-5 (4:2:2) component digital format was released in 1994 by the Panasonic corporation. The format uses the same type of cassette as the D-3 format, which uses a 1/2-inch-wide videotape enclosed within a cassette. The format also has four digital audio channels and a dedicated time-code channel. The maximum playing time for D-5 is 124 minutes. There is a high-definition television (HDTV) adapter, which can be added in order to permit HDTV recordings with a four-to-one compression ratio.

D-6 is a compression-free, component digital HDTV recording format developed by Philips and Toshiba. The recording is made onto a 3/4-inch-wide videotape enclosed within a cassette, providing a maximum recording time of 64 minutes. It also has twelve channels of audio along with a time-code channel.

D-7 (DVCPRO) format was developed by the Panasonic Corporation. The format was developed for use within industrial and broadcast applications, generally intended for ENG applications. It records the information using a special MP or metal-particle 6-mm videotape with a maximum recording time of 184 minutes. The format uses a digital sampling ratio of 4:1:1, which means that the luminance information is at full resolution; however, the chrominance resolution is half of what it is in 4:2:2. This is a component digital format that has a compression ratio of five to one and also has two digital audio tracks.

DCT (Digital Component Technology) format is a 4:2:2 component digital format developed by the Ampex Corporation. The format records onto a 3/4-inch- or 19-mm-wide videotape enclosed within a cassette. The format has a compression ratio of two to one and supports up to four channels of audio and a time-code channel. The DCT format has a maximum recording time of 208 minutes.

Digital Betacam format released by Sony Corporation in 1995. As with Betacam SP, Digital Betacam uses a 1/2-inch (12.7-mm) videotape enclosed within a cassette that is specially marked for use within a Digital Betacam machine. It is a 4:2:2 component digital format with a two-to-one compression ratio, along with four digital audio tracks and a time-code track. The maximum playing time is 124 minutes. This format is widely used throughout the industry and provides excellent results for color correction.

D-9 or Digital S format was developed by the JVC Corporation and is a component digital format. It has a sampling ratio of 4:2:2 and the recording is made on a 1/2-inch metal-particle videotape enclosed within a cassette. It actually uses the same cassette shell that is used for the VHS format. The format supports up to four digital audio tracks and the tape moves through the transport at a speed of 2.1 inches/sec. It has a compression ratio of 3.3 :1 and a maximum recording time of 104 minutes.

DV/DVC format is a component digital recording format that has a five-to-one compression ratio. It also supports up to two channels of digital audio. The information is recorded on a special 6-mm metal-evaporated videotape enclosed within a cassette. The format has a maximum recording time of 6.9 hours, using the long play mode with a DVCAM 184-minute videocassette. It has a sampling ratio of 4:1:1 in NTSC and 4:2:0 in PAL. It is widely used for consumer and professional applications.

DVCAM format from Sony is a component digital recording format. It supports up to two channels of digital audio and has a maximum recording time of 184 minutes, recording on a special 6-mm metal-evaporated cassetteenclosed videotape. The format is generally intended for professional or industrial applications. In NTSC, it records with a sampling ratio of 4:1:1, which means that the luminance information is at full resolution; however, the chrominance resolution is half of what it is in 4:2:2. When used in PAL, the sampling ratio is 4:2:0, which means that there is full luminance resolution as in 4:2:2; however, the chrominance only has half resolution on every other scanning line.

DVCPRO 50 format is a component digital format that uses a sampling ratio of 4:2:2 and has a compression ratio of 3.3 : 1. It has a maximum recording time of 90 minutes and supports up to four channels of digital audio. The information is recorded on a cassette-enclosed 6.35-mm-wide videotape.

Digital 8 format from Sony is a component digital format that has a sampling ratio of 4:1:1 in NTSC and 4:2:0 in PAL. It uses a compression ratio of five to one. The format records the information onto an 8-mm-wide videotape enclosed within a cassette running at a speed of 28.666 millimeters/sec, or 1.12 inches/sec. The maximum recording time is 90 minutes on either a metal-evaporated or metal-particle videotape, and it supports up to two channels of digital audio.

HDCAM is an HDTV format that records a digital HDTV signal plus four channels of audio onto a 1/2-inch-wide videotape enclosed within a cassette, with a compression ratio of 4.4 to 1. The HDCAM format was introduced in 1997 and is basically to HDTV what Digital Betacam is to standard-definition television (SDTV). The maximum recording time for HDCAM is 124 minutes.

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Analog Recording Formats

Cecep SWP — Sat, 19 Sep 2009 06:54:33 +0000

1-Inch Type C is an open-reel format that records a composite video signal onto a 1-inch-wide videotape. There are three audio tracks, two for the program audio and one for longitudinal time code. This format was introduced in 1978 and has been widely used throughout the production and postproduction industry. The maximum playing time available is 180 minutes, and the tape moves through the machine at a speed of 9.6 inches/sec.

8-mm format is a composite analog format. It was originally released by Eastman Kodak. It provides an image quality that is slightly superior to that of VHS. It makes the recording on an 8-mm metal-particle videotape enclosed within a cassette. It supports one stereo AFM and one stereo PCM audio track and has a maximum recording time in NTSC of 240 minutes, running at LP speed, using a P6–120 videocassette. In PAL, the format has a maximum recording time of 180 minutes, using a P5–90 videocassette, running at LP speed.

Betacam is an analog component format developed by Sony Corporation in 1982 and uses a 1/2-inch (12.7-mm) videotape enclosed within a cassette. The format supports a maximum recording time of 30 minutes. Besides being able to record composite video, the format has the option of recording a Y, R-Y, B-Y component signal and supports up to two channels of audio and a timecode track. This format has become extremely popular for electronic news gathering (ENG) applications.

Betacam SP (Superior Performance) format released by Sony Corporation in 1987. The format supports videocassettes with a longer running time than Betacam. As with its Betacam counterpart, Betacam SP uses 18 Video Color Correction for Nonlinear Editors a 1/2-inch (12.7-mm)-wide videotape enclosed within a cassette. The format supports a maximum recording time of 90 minutes and has four channels of audio, two of which are FM tracks, which provide high-quality audio reproduction. The change from Betacam to Betacam SP saw the format evolve from being used for news-gathering applications and industrial use to being widely used within the postproduction industry.

Betamax is an analog videocassette format intended for consumer use that was originally developed by Sony. It utilizes a half-inch (12.5-mm) ferro-chrome videotape enclosed within a cassette. It supports up to two channels of audio and has a maximum recording time of 300 minutes in NTSC. The maximum recording time in PAL is 215 minutes.

Hi-8 format is an analog format that can receive a video input in composite or Y/C mode, which separates the chrominance and luminance information. It was introduced by Sony in 1989. It records the information onto an 8-mm-wide metal-evaporated cassette-enclosed videotape. It is basically a consumer format; however, it is sometimes used for professional applications. The format has a maximum recording time of 240 minutes in NTSC, running at LP speed, using a P6–120ME videocassette. In PAL, the maximum recording time is 180 minutes in LP mode, using a P5–90ME videocassette.

S-VHS format utilizes a special high-energy videotape and provides superior resolution over its VHS counterpart by receiving the input video in Y/C mode, which separates the chrominance from the luminance information. The use of the Y/C input signal significantly improves the color reproduction. The format has a maximum recording time of 480 minutes, using an ST-160 videocassette running at EP speed in NTSC. The maximum recording time in PAL is 480 minutes at LP speed, using an SE-240 videocassette.

U-Matic or 3/4-inch format as it’s sometimes known, is essentially an industrial format released in 1968 and has been widely used throughout the production and postproduction industry due to its compact size and quality. It was widely used within the news business for field ENG. It records using a 3/4-inch-wide videotape enclosed within a cassette and has a maximum recording time of 75 minutes. The U-Matic format is a composite analog video format that has two audio tracks, one of which is frequently used for the time code. In order to maintain superior color rendition, the chrominance and luminance information is separated during recording and restored during playback. There are also certain professional models that have their own dedicated time-code channel, which is known as “address track time code.”

VHS is a consumer format that records an analog composite signal along with two channels of audio. The format records using a 1/2-inch-wide videotape enclosed within a specially designed cassette. There are three speeds available. These are: 1.94 inches per second (known as SP or standard play), which yields the best results; LP (long play) mode, which records at 0.66 inches/sec; and finally, SLP (super long play), which records at 0.44 inches per second. The best quality is of course achieved when using the SP mode. The format has a maximum recording time of 320 minutes in LP mode, using a T-160 videocassette in NTSC, and 600 minutes using an E-300 in PAL at LP mode.

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Recording Voice-Overs

Cecep SWP — Sun, 05 Oct 2008 18:40:08 +0000

Need to setup a home studio to record voice narration for home videos, indie
productions, commercials, and more? Here’s how …

Do you already have a computer with a sound card that can act as your
digital recorder? You just need to add some inexpensive recording equipment
and software to your PC, and you can produce high-quality, effective voice
recordings easily. What other gear do you need?

Microphone.
To get your voice into the computer, you need a microphone. Don’t use
the crummy little one that came with your computer. High-quality,
inexpensive mics abound and sound far better than that trash. For basic
voice work, I’d suggest either the Shure SM57 or SM58. These are rugged,
good-sounding dynamic microphones. The ‘58 is especially suited for female
voice as it reduces sibilance (excessive esses) somewhat. Males can choose
either. Both mics are available from music or audio equipment suppliers for
under $100 (American Musical Supply, BH Photo/Video, Musician’s Friend,
and others). Also, get a proper mic cable and a desk stand to hold the mic
while you’re speaking.

Microphone preamp.
Microphones put out such a low amount of electricity that their signal needs to
be boosted. The sound card’s mic input includes the necessary preamplifier.
Unfortunately, much like the cheapo mic that shipped with your box, most sound
card mic preamps are too noisy for serious work. In a pinch you could use it, but
at least, use it with a better mic.

For the preamp, you can choose either a small mixer to work with your mic or
a dedicated device. Mixers essentially let you connect several microphones and
other devices (such as a CD player) to one place and adjust their volumes
independently. The Behringer Eurorack MX602A 6 Input Mixer has microphone
inputs, level controls, and costs less than $60. Alternately, two good choices for
stand-alone preamps include the DBX Mini-Pre Tube Mic Pre-amp and the ART
Tube MP Studio V3 Mic Pre-amp. Both are under $125 and available from the
same sources listed above.

If you do a lot of recording invest in higher quality mics, preamps, and a
dedicated computer audio interface. Two better mic choices include the
Marshall 2003 and the Rode NT1. For preamp needs, choose a combination preamp
and computer audio interface device such as the Edirol UA-5 or M-Audio Duo.

Speakers and headphones.
While computer speakers are adequate for recording, editing, and finishing
basic recordings, those built-in to laptops are useless.
Invest in some decent powered speakers, such as the Roland MA-8 Micro
Monitors, and use them instead. Play your recordings on a variety of
systems–home stereo, car, etc.–to check how they translate to other listening
environments. Also, you can’t listen on speakers when recording because they’ll
feedback when the microphone is on. Wear closed-ear headphones that keep
sound leaking from them from being picked up by the mic.

Recording software.
Choose recording software with editing facilities for fixing mistakes, compiling
the best bits, adding music and/or sound effects, creating special effects, and
delivering your finished voice tracks in the formats you need.
A “light” version of a professional recording program is Sonic Foundry’s Sound
Forge Studio 6.0

Quiet recording space.
Your goal is to record a clear, intimate voice track, and that means keeping noise
and the sound of the room OUT of the finished recording. Professionals record in
a sound booth specially designed to keep noises out and make their voice sound
good. These costs thousands of dollars and are a bit impractical for occasional work.
A clothing-filled, walk-in closet works as a makeshift sound booth, though.

Getting a good level
Even the most basic onboard sound card has three connections: mic in, line in,
and line (or headphone) out. Hook up your equipment by plugging your mic into
the mixer (or preamp) and plug the output of that device into your sound card’s
line in. Connect your headphones, too. (If you’re using a dedicted external
interface, you’d plug into that. It connects to the computer through a USB port.)

Next, set your volume at the mixer (or preamp) using its controls and level
meters. Start speaking, watch the meters, and slowly raise the volume until you
get close to 0 (zero) without going over.

Launch the software that controls your sound card (it’s usually the little speaker
icon in the system tray). Here is where you select your recording source (line in)
and adjust its volume. Set this at 100%–all the way up–and then control your
recording level with your external mixer or preamp.

Start your audio recording software and get into record ready. Record in mono,
not stereo, and at CD-quality (16 bits and 44kHz sampling rate). You’ll notice that
the audio software doesn’t have controls for setting levels, but you do rely on its
meters when recording. Never, EVER exceed 0 (zero) on your digital level meters.
Anything above that level will sound horribly distorted. You want any loud sound
to fall below digital 0 with the majority of your level well below that
(between -6 to -15 dB).

Mic technique
To greatly improve the sound of your recordings, get closer to the mic.
The farther away you are from it, the more you pick up the room around you.
Your voice starts to sound thin and distant, like a home video. Get closer and
your voice is more intimate–the prototypical narrator sound. Another advantage
to getting closer is the microphone itself may accentuate the lower frequencies
in your voice and that can make you sound more powerful. How close? Put your
lips between four and six inches away, about the width of your hand. Don’t talk
down into the mic. Instead position it above your nose pointed down at your lips.
Also, don’t position the mic dead center of your lips. Move it over to the right
slightly, say 20 degrees, off axis. This leaves a clear view of your script, too.

Obviously, locate your recording area away from noisy equipment, such as
computer fans. Put a little distance between the mic and the noise source.
Also, avoid salty foods immediately before your recording session. Have some
tepid water nearby and apply a little lip balm. These will keep your mouth and
lips lubricated. Nibbling on some sliced apples can help overcome dry mouth, too.

When you’re ready to record, turn away from the microphone. Take a deep
breath. Exhale. Take another deep breath. Open you mouth, turn back to
the microphone and begin to speak. This technique eliminates the sharp intake
of breath and lip smack that often occur when starting to speak.

Speak clearly and slowly. You can always tighten up your recording during
the editing stage. If you make a mistake, go back to the nearest sentence start
and continue on again, even if you flub just a word or two. Cutting in a single
word or phrase is difficult and doesn’t sound natural.

Editing the recordings
You don’t have to nail everything in one take. Record as many run-throughs as
needed and compile the best parts into the final recording. Listen back and
evaluate what you did. Is everything there that you need? Does it sound good?
Is the level right (not too low; not distorted)? If not, go back and re-record
the bits you need, listen back again, and repeat the process until you’re satisfied.

Editing sound is much like editing in a word processor. You can’t see the words,
but you do see a two-dimensional representation of the words as sound
waveforms. And you can hear the words as you play them. You manipulate these
waveforms just like you move words around in your word processor. Cutting, copying, pasting–all the techniques you’re already familiar with apply when editing sound.

Before you begin editing, turn off the mic, disconnect the headphones, and
switch to speakers. Obviously, delete what’s not needed, such as a throat clear
before you started speaking, any chatter between takes, extraneous noises,
and so forth. Once you’ve eliminated the junk, move toward improving your
performance. If you did multiple attempts at the script, find the best takes and
build your final version from them.

Listen critically to any changes you make. I find that taking a long break let’s you
approach the recording once again with fresh ears. Can you make it better?
Is the volume consistent? Are there any noises, background sounds, or other
unwanted parts that you could eliminate or reduce?

After editing the voice, you can add music or sound effects to sweeten the final
version. To add music using Sound Forge, open the music file in your audio
software, select, and copy it to the clipboard. You may need to trim the music
to match the length of your voice recording, first. Then, position the cursor at
the start of your voice recording, and select Edit > Paste Special > Mix.
Here you can control the level of the music (source) in relation to your
voice (destination). Double-check the mix to make sure you can hear your voice
recording clearly with the music playing in the background.

As a final step, use your audio software’s normalization process to maximize
the recording’s volume. Select the entire waveform and normalize it to
-0.10 dB (98.86%). Save this file to the audio format you need, for instance, MP3.

###Jeffrey P. Fisher

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