MST 230: Online Media Production Two
'The Digital Producer' Readings
CHAPTER 4 - 'Preparing to Shoot'
-In the late 1980s, D1 and D2 digital video decks (digital recording and playback of component and composite video, respectively) started appearing in broadcast facilities around the same time that digital nonlinear editors started creating a stir at NAB con-ventions. QuickTime became a hit in the realm of multimedia soon afterward.
New Formats to Consider
DV, DigitalĐS, and Digital Betacam: New Life for Videotape
• Digital Betacam: As you might expect, the digital version of the venerated Betacam SP format.
• DigitalĐS: A high-quality digital format that uses the same size cassettes as S-VHS. You might think of it as the next generation of S-VHS.
• DV formats (including DVCAM, DVCPro, and MiniDV): A new format that has made a big splash in recent years, replacing analog formats in many news operations due to the ever popular combination of high quality with low cost.
• Digital 8: Another new format that is just recently coming into use. Like DigitalĐS, Digital 8 is the next generation of another popular "prosumer" format, Hi8.
• Designed with consumer cameras in mind, MiniDV cassettes are smaller, lighter, and less robust than DVCAM tapes. They are also more subject to damage during heavy use, for example when edit-ing from tape.
• One often overlooked fact is that with MiniDV tapes, audio tracks are not locked to video. DVCam has a higher tape speed, which allows audio to be locked to video and produces less dropout in the audio channels. With MiniDV you will experience more pops and mutes in the tracks. If first-rate audio is important to your shoot, choose DVCam.
THE DIGITAL ADVANTAGE:
- The big gain with a digital format, if handled properly, is that you can do away with generation loss. Digital formats allow you to basi-cally make pristine copies of the data from tape to disk drive and back to tape again with no loss of image quality.
• Check for postproduction compatibility: Before choosing a digital format, make sure your posting facilities can handle the format in its native form.
• Consider your nonlinear editing requirements: If you are working with one of the DV formats, consider that most DV-native editing systems are not as full-featured as high-end editing systems such as the Avid Media Composer, although new DV editing systems appearing Fall of 1999 from Avid and others aim to change that.
• Consider your effects editing requirements: The benefits of digital copies can also be undone by multiple passes that require encoding and re-encoding of signals when applying, rendering, and reapplying effects.
FIREWIRES:
Firewire is the colorful trademark name Apple gave to the connection and transfer technology it pioneered in the mid-1980s which was adopted industry-wide in 1995 as the IEEE 1394 standard. A number of IEEE 1394 products are now available including digital camcorders with the IEEE 1394 link, IEEE 1394 digital video editing equipment, digital VCRs, digital cameras, digital audio players, 1394 ICs, and a wealth of other infrastruc-ture products such as connectors, cables, test equipment, software tool-kits, and emulation models.
• Many of the digital cameras nowadays allow you to record your standard-resolution source footage in the 16:9 aspect ratio of HDTV. You don't capture all the pixels of a true HDTV signal, but you do have the option of "up-rezing" (as they say) to high defini-tion for future broadcasts. • A "halfway there" option that is slightly more expensive than video but not as expensive as HDTV is film. Yes indeed, it's back to the future with a format like Super16 that allows you to capture high-quality ("high-definition" by default) footage
COMPRESSION:
Compression involves applying mathematical algorithms to reduce the size of digital data -- by reducing or eliminating duplicate information, for example. There are many different formulae for performing this digital magic -- Motion JPEG and MPEG are two common standards. The loss of quality can range from imperceptible to severe. Damage to the image results in so-called "artifacts" which look like tiny blocky areas where sharper detail once existed.
-Here's the basic rundown of the types of compression you can expect with the major digital video formats described in this chapter.
Format Color Sampling Compression Ratio Data Rate (mega-bits per sec-ond)
D1, D5 4:2:2 1:1 (none) approx.160 mbps
Digital Betacam 4:2:2 1.6:1 approx.100 mbps
DigitalĐS 4:1:1 3.3:1 50 mbps
DV formats 4:1:1 5:1 25 mbps
Digital 8 4:1:1 5:1 25 mbps
DIGITAL REVOLUTION:
• Random access in the field:
• Deleting clips and saving storage:
• Editing in the field:
• No need to transfer or digitize:
• Environmental resistance: Environmental performance prob-lems often encountered by VTR are controlled by the disk's char-acteristics. Stable operation is ensured against dust, sand and salt, and humidity.
- Smaller Digital Technologies = lighter, easier to transport, set up in the field.