Model 585 Time Scaling Processor Issue 2 Part Number 91796
Model 585 Time Scaling Processor Dolby Laboratories, Inc. Corporate Headquarters Dolby Laboratories, Inc. 100 Potrero Avenue San Francisco, CA 94103-4813 Telephone 415-558-0200 Fax 415-863-1373 www.dolby.com European Headquarters Dolby Laboratories, Inc.
Model 585 Time Scaling Processor Table of Contents List of Figures................................................................................................................ v List of Tables ................................................................................................................. v Regulatory Notices ....................................................................................................... vi Fusing Information ......................................................
Model 585 Time Scaling Processor Chapter 6 Principles of Operation.........................................................................6-1 6.1 Multichannel Delivery ...................................................................6-1 6.2 Development of Time Scaling.......................................................6-2 6.2.1 Time-Domain Solutions ....................................................6-2 6.2.2 Frequency-Domain Solutions ...........................................6-2 6.2.
Model 585 Time Scaling Processor List of Figures Figure 1 Checking the Main Fuse..................................................................................viii Figure 2-1 Connections: Signal In and Out...................................................................2-2 Figure 2-2 Connections: Remote RS-232, GP I/O, Metadata In and Out .....................2-3 Figure 2-3 Model 585 Front Panel ................................................................................
Model 585 Time Scaling Processor Regulatory Notices USA This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
Model 585 Time Scaling Processor IMPORTANT SAFETY NOTICE This unit complies with the safety standard EN60065. The unit shall not be exposed to dripping or splashing and no objects filled with liquids, such as coffee cups, shall be placed on the equipment. To ensure safe operation and to guard against potential shock hazard or risk of fire, the following must be observed: o Ensure that your mains supply is in the correct range for the input power requirement of the unit.
Model 585 Time Scaling Processor Fusing Information WARNING: To reduce the risk of fire, replace fuses only with the same type and rating. The unit uses a universal switching power supply that handles the full range of nominal mains voltages between 90 and 264 VAC and any frequency between 50 and 60 Hz. Check Main Fuse The Main fuse rating is: T 1A L (1 Amp, 250 V, 20 mm, time-lag, low-breaking capacity) for all operating voltages.
Model 585 Time Scaling Processor Chapter 1 Introduction The Model 585 Time Scaling Processor delivers true time scaling and pitch shifting for the studio professional. A change in the playback speed of analog tape—or in the sample playback rate for digital formats—has always brought about a change in the audio pitch as well as the duration of the audio program being played. However, this fixed link between playback speed and pitch has often meant a compromise in audio quality.
Model 585 Time Scaling Processor Introduction Pitch shifting, sometimes referred to in other documents as pitch scaling, alters the perceived frequency of the audio signal from that of the original signal, while leaving the duration of the signal the same as the original. Pitch shifting and its implementation using Model 585 is covered in Chapter 4.
Model 585 Time Scaling Processor Chapter 2 Getting Started This chapter covers connection requirements for Model 585 and the basics of using the front-panel controls. 2.1 Unpacking and Inspection Before unpacking Model 585, inspect the outer carton for shipping damage. If the carton shows damage, inspect Model 585 in the associated areas. The BNC connectors on the rear panel are covered with protective plastic caps. The following items are provided with Model 585: • • • 2.
Model 585 Time Scaling Processor • • Getting Started Cables. We recommend standard 75Ω BNC cables for digital audio signal connections. To connect to digital equipment with 110Ω XLR connectors, use impedance-matching transformers (readily available from Canare, Neutrik, and other manufacturers). Input channel 1/2 must be connected to a valid digital audio signal for proper operation of the unit. Model 585 can be used between any two products that carry PCM audio.
Model 585 Time Scaling Processor Getting Started Figure 2-1 definitions: 1. Digital Inputs. Model 585 requires PCM audio input at a sample rate of 48 kHz ± 15%. Each input has two connectors; either connector can be used for the input or as a loop-through for that channel pair. If the loop-through connection is not being used, it must be fitted with a 75Ω termination. The last device in the loop-through signal chain must be terminated with 75Ω. Note: Ch 1/2 requires a valid PCM digital audio signal.
Model 585 Time Scaling Processor 2.3.3 Getting Started Remote Connection Ports The Remote (9-pin) In and Remote (9-pin) Out ports are reserved for future enhancements. 2.4 Front Panel The front panel is shown with feature definitions in Figure 2-3.
Model 585 Time Scaling Processor 2.4.1 Getting Started Reading the Display After powering up, Model 585 displays the main status menu. The factory default is: 5.1 + 2 Sens=5 +0.0 The main status menu shows you: 2.4.2 • On the upper line, the program configuration and the sensitivity level. In this example, 5.1 + 2 defines two programs: Program 1, a 5.1 mix; and Program 2, a two-channel mix. The sensitivity level is set to 5. • The amount of pitch shifting on the lower line, +0.
Model 585 Time Scaling Processor Getting Started Table 2-1 Front-Panel Button Definitions Button Result Shift Selects the alternate function for a button. To select Status or Bypass, hold down Shift and press the button under the selection you want. Setup From any status menu, displays the last setup menu viewed, or the Unit Setup menu if a setup menu has not been viewed in the previous five minutes. From any setup menu, displays the Unit Setup menu.
Model 585 Time Scaling Processor Getting Started Caution: Adjusting the pitch shift value or sensitivity level in the main status menu activates that value change immediately; pressing Enter is not required. You do not have the option to press Esc to return to the original setting, so note what that setting is before rotating the knob. In the Play menu, the knob triggers different functions than in all other menus. See Knob Function in Play Menu on page 3-4 for details. 2.
Model 585 Time Scaling Processor 2.6 Getting Started Setup Menu Options in the setup menu are: • Program Config • Operating Mode • Transport • System Settings Press Enter to view the menu for the option on the second line of the display. The Transport menu operates the time scaling function, and is described in Section 3.1, Transport Menu. The other three menus are described in this section. 2.6.1 Program Configuration The Program Config menu initially displays the active program configuration.
Model 585 Time Scaling Processor Getting Started Channel assignments within each program configuration follow standard mapping, as shown in Table 7-1 in Chapter 7, Reference Data. The only exception is the lowfrequency effects (LFE) channel, which can also be assigned manually, as described in Section 2.6.2, Operating Mode. 2.6.2 Operating Mode In the Operating Mode menu, you have six options: Sensitivity, Pitch, Processing Delay, Clock Source, DC Filter, and LFE Channel.
Model 585 Time Scaling Processor Getting Started Note: Sensitivity should remain at 5–high for most program material. If the setting must be changed, the change should be limited to the length of the specific passage that requires the change, and then returned to 5–high. Setting changes activate in real time when changed using the front-panel controls. Pitch You can use the Pitch menu to select a new scaling value by pressing the arrow buttons or rotating the knob.
Model 585 Time Scaling Processor 2.6.3 Getting Started System Settings In the System Settings menu, the options are Display Mode and Brightness. Brightness You can use the Brightness menu to adjust the intensity of the display. Changes you make in this menu are activated immediately, without pressing Enter. Display Mode Use Display Mode to choose the unit of adjustment displayed for pitch shifting: frames, ¢ (cents), or % (percent). Frame mode uses percent as the unit of adjustment.
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Model 585 Time Scaling Processor Chapter 3 Time Scaling Time scaling alters the duration of an audio signal, but leaves the perceived pitch unchanged from the original signal. Model 585 offers stand-alone, high-quality multichannel time scaling of short program segments by using the Transport menu. At the standard 48 kHz sampling rate, Model 585 can store approximately 23 minutes of mono, 11.5 minutes of stereo, 6 minutes of four-channel, 4 minutes of 5.
Model 585 Time Scaling Processor 3.1.1 Time Scaling Play Enter the Play menu to manipulate the time scaling of the clip stored in memory, or to simply play the clip, or any part of it. When you enter the Play menu, you see: ■ ■ /► 00:00.00 % In Out Status Setup Enter The upper line shows the transport status, the point in the stored clip where you last viewed the menu, and a clock symbol. When you enter the play menu, the transport status is in stop mode, as shown here.
Model 585 Time Scaling Processor Time Scaling When a clip is stored in the Model 585 memory, the Play menu displays the scaled time value of that clip. If you change the scaling percentage, the length of the scaled clip changes to reflect that, and the Play menu display, In point, and Out point all update accordingly. Stop/Play In the Play menu, Setup acts as a Stop/Play toggle. When you enter the Play menu, Model 585 is in stop mode. When you press Setup in stop mode, playback of the clip starts.
Model 585 Time Scaling Processor Time Scaling In Point The In point is the point in the audio clip when playback starts. If the transport position is at or before the In point when you press Play, playback begins at the In point. When the transport is at the In point, the display shows a dot before the word In: ·In. To set or reset the In point to the current transport position, press Shift + set the In point in either play or stop mode. .
Model 585 Time Scaling Processor Time Scaling you release Shift, the transport returns to stop mode at the position in the clip when you release Shift. Holding Shift makes it particularly easy to move through the clip rapidly, but it also allows you to move slowly at a steady pace, without having to manually turn the knob. 3.1.2 Record When you enter the Record menu, you see: ■ ■ /z 00:00.00 P1 Status Setup Enter In this menu, the Setup button is a Stop/Record toggle.
Model 585 Time Scaling Processor Time Scaling all eight channels will be recorded, and the available recording memory is slightly less than three minutes at 48 kHz. To select which program to record, use the arrow buttons, then press Enter. 3.2 Time Scaling of Longer Programs While stand-alone time scaling using the Transport menu works well on short audio segments, it is performed offline, using the precision of the Transport menu controls.
Model 585 Time Scaling Processor Chapter 4 Pitch Shifting Pitch shifting, sometimes referred to in other documents as pitch scaling, alters the perceived frequency of the audio signal from that of the original signal without altering the duration of the signal. Pitch shifting is most often used to compensate for a required change in playback rate of a program, so that the audio is reproduced at the original pitch in spite of the rate change.
Model 585 Time Scaling Processor Pitch Shifting 2. Use the knob or arrow buttons to scroll through the second line display until you get to Pitch, then press Enter. 3. Use the knob or arrow buttons to adjust the value on the second line. A flashing block displays as you change the value. The new value activates only when you press Enter. To leave the active value in effect and return the display to that value, press Esc.
Model 585 Time Scaling Processor Chapter 5 Applications Model 585 can be used to compensate for pitch changes in many applications, such as: • • • When changing from 24 to 25 fps (for example, when converting a film source to video for broadcast or DVD release) When changing from 25 to 24 fps (for example, when converting a video source to 35 mm film for theatrical exhibition) When changing the duration of content to fit an allotted broadcast time slot Model 585 can also be used in many equipment configu
Model 585 Time Scaling Processor Applications Source Audio Model 585 2. Model 585 Adjust using Transport menu, In/Out point 3. Model 585 Audio recorder or straight to broadcast 1. Record Play Figure 5-1 Stand-Alone Time Scaling For details on how to operate Model 585 to perform stand-alone time scaling, see Section 3.1, Transport Menu. 5.
Model 585 Time Scaling Processor Applications Figure 5-2 Single-Pass Pitch Shifting In Figure 5-2, the source program video and audio are delivered separately. The playback VTR is used to adjust the speed of the program to conform to the requirements for final delivery. The playback VTR also sends timecode to the multitrack DTRS, which adjusts the speed of the multichannel audio. Model 585 compensates for the speed change by adjusting the pitch shifting to the opposite value, as discussed in section 4.2.
Virtual Dolby Technologies Test DVD Track List iv
Model 585 Time Scaling Processor Chapter 6 Principles of Operation Time scaling of audio has been accomplished previously using a variety of approaches. Model 585 differs from previous products in two fundamental ways: • • 6.1 It provides phase-synchronous multichannel processing in addition to processing of simpler programs. It steps away from the weaknesses of the various previous approaches.
Model 585 Time Scaling Processor 6.2 Principles of Operation Development of Time Scaling Time scaling of audio was first achieved in the 1950s with the invention by Fairbanks, Everitt, and Jaeger1 of a modified tape recorder. Their modified machine discarded and repeated sections of audio signal by using a rotating playback head, and became known as the sampling or splicing technique. 6.2.
Model 585 Time Scaling Processor Principles of Operation Frequency-domain solutions proved useful in certain situations, particularly where processing time was not a major factor. However, they also produced characteristic artifacts, and could only be used for a limited selection of material. Artifacts of frequency-domain solutions often include audible phase artifacts and the loss of definition of transient material. 6.2.
Model 585 Time Scaling Processor Principles of Operation same characteristics (such as common onset, common harmonic properties, or in multichannel audio, common spatial location), and breaks down the complete sound into its component parts before discarding or adding samples. Model 585 also takes advantage of psychoacoustic phenomena that have been studied previously for use in audio coding schemes. For example, at smaller time scales, the human brain focuses on a single auditory event at a given time.
Model 585 Time Scaling Processor Chapter 7 Reference Data 7.1 Channel Mapping Table 7-1 Channel Mapping according to Program Configuration The program number (1–8) identifies the individual programs associated with each channel. So, the entry 2C/2S means “Program 2, Center channel/Program 2, Surround channel.” Channel Program Configuration 1/2 3/4 5/6 7/8 5.1 + 2 1L/1R 1C/1LFE 1Ls/1Rs 2L/2R 5.
Model 585 Time Scaling Processor Reference Data Note: In multichannel audio, the LFE channel is bandwidth-limited, so to properly process the complete program audio, the LFE channel must be assigned according to standard channel mapping. 7.2 Specifications Time Scaling/Pitch Correction Process Dolby proprietary, real-time processing Channel Modes/Program Configurations Processes up to eight discrete channels of audio; supports all Dolby® E program configurations, including 5.1, 5.
Model 585 Time Scaling Processor Reference Data Dynamic Range >110 dB Delay 400 to 480 ms, user-selectable Digital Audio Inputs Four BNC female connectors with loop-through, 75Ω, unbalanced, signal levels per AES-3ID-1995/SMPTE 276M specifications Digital Audio Outputs Four BNC female connectors, 75Ω, unbalanced, signal levels per AES-3ID1995/SMPTE 276M specifications AES Reference Input BNC female with loop-through, 75Ω, unbalanced, signal levels per AES3-ID Audio Word Length Up to 24 bits Serial Remote
Model 585 Time Scaling Processor Reference Data Dimensions and Weight 2-U rack-mount: 88 × 483 × 324 mm (3.5 × 19 × 12.75 inches) Net: 6.5 kg (14.
