Dolby LM100 Broadcast Loudness Meter User's Manual

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List of Tables Table 3-1 Special Function Button Combinations.................................................................................14 Table 3-2 Error Conditions and Indicators ............................................................................................15 Table 4-1 Common Reference Levels ..................................................................................................30 Table 4-2 Input Clipping Alarm Parameters..........................................................................................31 Table 4-3 Over Level Alarm Parameters ..............................................................................................33 Table 4-4 Under-Level Alarm Parameters ............................................................................................33 Table 4-5 Under-Level Alarm Parameters ............................................................................................33 Table 4-6 dialnorm Threshold Alarm Parameters.................................................................................33 Table 5-1 Application Examples for Short-Term and Infinite Methods .................................................42 Table 5-2 Available Alarm Types..........................................................................................................46 Table 5-3 Alarm Output Port.................................................................................................................47 Table 5-4 GP I/O Port ...........................................................................................................................49 Dolby ® LM100 Broadcast Loudness Meter User’s Manual xi
Chapter 1 Introduction This chapter introduces the updated Dolby ® LM100 Broadcast Loudness Meter and covers: • LM100 Front and Rear Panels • LM100 Configurations Beset by loudness discrepancies—between programs or channels of television services— the broadcast, satellite, and cable TV industries have long required a simple method for quantifying perceived audio levels. These industries have traditionally controlled their program levels using either a PPM or VU meter, neither of which measures subjective loudness. The LM100 features revolutionary measurement technologies capable of quantifying the subjective loudness of broadcast programming, eliminating the need for home listeners to adjust the volume. For details on Dolby metadata, see A Guide to Dolby Metadata, available at dolby.com. The LM100 measurement algorithms yield more consistent results than either PPM or VU meters with sources that primarily contain dialogue. They comply with EBU R128, ITU‐R BS.1770‐1, ITU‐R BS.1770‐2, and IEC 61672‐1 and 61672‐2. The LM100 can determine the unweighted true‐peak level per ITU‐R BS.1770‐1 Annex 2. The LM100 measures the loudness range in accordance with EBU Tech 3342, and displays measurements in an easy‐to‐understand numerical format. You can use the LM100 in applications ranging from postproduction and quality control to final transmission and program turnaround. The LM100 accepts stereo PCM, two‐channel analog (baseband), and multichannel Dolby E and Dolby Digital (AC‐3) audio inputs. For a facility working with analog or two‐channel PCM audio, the unit can accurately quantify the subjective loudness of dialogue (and therefore the overall program level), which is useful in almost any environment where audio levels must be assessed. For facilities working with Dolby Digital or Dolby E signals, the LM100 can also measure or validate the existing dialogue level (also known as dialogue normalization, or dialnorm) parameter value within a Dolby Digital or Dolby E program by making a direct, objective comparison to the actual measured dialogue level value. It can also display a range of other audio signal information. The unit includes a set of user‐definable alarms and monitoring functions that can inform an operator of input loss, signal clipping, RF overmodulation, high or low signal levels, silence, phase errors, and incorrectly set dialogue level values. A dedicated GPI/O port provides a tally of these alarm conditions, with more extensive monitoring available through the serial ports and an internal event log. Dolby ® LM100 Broadcast Loudness Meter User’s Manual 1
Page 1 and 2: ® Dolby LM100 Broadcast Loudness M
Page 3 and 4: Regulatory Notices FCC NOTE: This e
Page 5 and 6: Fuses WARNING: Check that the corre
Page 7 and 8: Table of Contents Chapter 1: Introd
Page 9: List of Figures Figure 2-1 LM100-NT
Page 13 and 14: Chapter 2 Getting Started This chap
Page 15 and 16: Getting Started Figure 2‐1 Analog
Page 17 and 18: Power 2.5 Power Warning: Before app
Page 19 and 20: Installing the Remote Software Use
Page 21: Installing the Remote Software Figu
Page 24 and 25: Front-Panel Controls incrementally.
Page 26 and 27: Front-Panel Controls Table 3-2 Erro
Page 28 and 29: Menus Figure 4‐1 Figure 4-1 Main
Page 30 and 31: Menus Figure 4‐8 Figure 4-8 Main
Page 32 and 33: Menus Figure 4‐10 Figure 4-10 Mai
Page 34 and 35: Menus If EBUis the selected measure
Page 36 and 37: Menus conditions are a loss of inpu
Page 38 and 39: Menus Short-Term Window Length When
Page 40 and 41: Menus Analog Input Calibration Use
Page 42 and 43: Menus Table 4-2 Input Clipping Alar
Page 44 and 45: Menus Table 4-6 dialnorm Threshold
Page 46 and 47: Menus To recall a preset follow the
Page 48 and 49: Menus Remote Mode When you select R
Page 50 and 51: Features • The main status screen
Page 52 and 53: Features Figure 5‐1 Figure 5-1 Li
Page 54 and 55: Features Figure 5‐2 :20 :19 :18 :
Page 56 and 57: Features The other selections are a
Page 58 and 59: Features In the System Log menu, to
Page 61 and 62:
Appendix LM100 Specifications Core
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