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- Page 1 ® Dolby LM100 Broadcast Loudness Meter User’s Manual Issue 4 Part Number 91846...
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Page 2: Corporate Headquarters
European Headquarters Dolby Laboratories, Inc. Wootton Bassett Wiltshire SN4 8QJ England Telephone 44‐1793‐842100 Fax 44‐1793‐842101 DISCLAIMER OF WARRANTIES: EQUIPMENT MANUFACTURED BY DOLBY LABORATORIES IS WARRANTED AGAINST DEFECTS IN MATERIALS AND WORKMANSHIP FOR A PERIOD OF ONE YEAR FROM THE DATE OF PURCHASE. THERE ARE NO OTHER EXPRESS OR IMPLIED WARRANTIES AND NO WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, OR OF NONINFRINGEMENT OF THIRD‐PARTY RIGHTS (INCLUDING, BUT NOT LIMITED TO, COPYRIGHT AND PATENT RIGHTS). LIMITATION OF LIABILITY: IT IS UNDERSTOOD AND AGREED THAT DOLBY LABORATORIES’ LIABILITY, WHETHER IN CONTRACT, IN TORT, UNDER ANY WARRANTY, IN NEGLIGENCE, OR OTHERWISE, SHALL NOT EXCEED THE COST OF REPAIR OR REPLACEMENT OF THE DEFECTIVE COMPONENTS OR ACCUSED INFRINGING DEVICES, AND UNDER NO CIRCUMSTANCES SHALL DOLBY LABORATORIES BE LIABLE FOR INCIDENTAL, SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, DAMAGE TO SOFTWARE OR RECORDED AUDIO OR VISUAL MATERIAL), COST OF DEFENSE, OR LOSS OF USE, REVENUE, OR PROFIT, EVEN IF DOLBY LABORATORIES OR ITS AGENTS HAVE BEEN ADVISED, ORALLY OR IN WRITING, OF THE POSSIBILITY OF SUCH DAMAGES. . Dolby and the double‐D symbol are registered trademarks of Dolby Laboratories. Dialogue Intelligence is a Part Number 91846 trademark of Dolby Laboratories. All other trademarks remain the property of their respective owners. Issue 4 © 2008 Dolby Laboratories. All rights reserved. S08/17486/19783 ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 3: Regulatory Notices
Important Safety Instructions Read these instructions. Keep these instructions. Heed all warnings. Follow all instructions. Do not use this apparatus near water. WARNING: To reduce the risk of fire or electric shock, do not expose this apparatus to rain or moisture. Clean only with dry cloth. Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat. No naked flame sources, such as lighted candles, should be placed on the apparatus. 10. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus. 11. Only use attachments/accessories specified by the manufacturer. 12. Unplug this apparatus during lightning storms or when unused for long periods of time. 13. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as the power‐supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped. 14. Do not expose the apparatus to dripping or splashing; no objects filled with liquids, such as vases, shall be placed on the apparatus. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... - Page 4 22. The power cord with CEE7/7 plug supplied with this unit for use in Continental Europe must be connected to a polarised mains socket, or the socket must be supplied via a residual current breaker (RCD). This power cord is not suitable for use in the UK. To use the cord in the UK cut off the CEE7/7 plug and replace with an approved BS 1363 13A plug: • The green and yellow core must be connected to the terminal in the plug identified by the letter E, or by the earth symbol , or colored green, or green and yellow. • The blue core must be connected to the terminal marked with the letter N or colored black. • The brown core must be connected to the terminal marked with the letter L or colored red. 23. This apparatus must be earthed. Fuses WARNING: Check that the correct fuses have been installed. For continued protection against risk of fire, replace only with fuses of the same type and rating. For details on fuse rating and instructions on fuse replacement, see Main Fuse on page 6. WEEE PRODUCT END‐OF‐LIFE INFORMATION This product was designed and built by Dolby Laboratories to provide many years of service, and is backed by our commitment to provide high‐quality support. When it eventually reaches the end of its serviceable life, it should be disposed of in accordance with local or national legislation. For current information, please visit our website at: www.dolby.com/environment. ® Dolby LM100 Broadcast Loudness Meter User’s Manual...
- Page 5 Assicurarsi che il selettore di cambio tensione sia posizionato sul valore corretto. Assicurarsi che la portata ed il tipo di fusibili siano quelli prescritti dalla casa costruttrice. Lʹapparecchiatura deve avere un collegamento di messa a terra ben eseguito; anche la connessione rete deve avere un collegamento a terra. Il cavo di alimentazione a corredo dellʹapparecchiatura deve essere collegato come segue: Filo tensione—Marrone Neutro—Blu Massa—Verde/Giallo AVISO IMPORTANTE DE SEGURIDAD Esta unidad cumple con la norma de seguridad EN60065. La unidad no debe ser expuesta a goteos o salpicaduras y no deben colocarse sobre el equipo recipientes con liquidos, como tazas de cafe. Para asegurarse un funcionamiento seguro y prevenir cualquier posible peligro de descarga o riesgo de incendio, se han de observar las siguientes precauciones: Asegúrese que el selector de tensión esté ajustado a la tensión correcta para su alimentación. Asegúrese que los fusibles colocados son del tipo y valor correctos, tal como se marca en la unidad. La unidad debe ser puesta a tierra, conectándola a un conector de red correctamente cableado y puesto a tierra. El cable de red suministrado con esta unidad, debe ser cableado como sigue: Vivo—Marrón Neutro—Azul Tierra—Verde/Amarillo VIKTIGA SÄKERHETSÅTGÄRDER! Denna enhet uppfyller säkerhetsstandard EN60065. Enheten får ej utsättas för yttre åverkan samt föremål innehållande vätska, såsom kaffemuggar, får ej placeras på utrustningen. För att garantera säkerheten och gardera mot eventuell elchock eller brandrisk, måste följande observeras: Kontrollera att spänningsväljaren är inställd på korrekt nätspänning. Konrollera att säkringarna är av rätt typ och för rätt strömstyrka så som anvisningarna på enheten föreskriver. Enheten måste vara jordad genom anslutning till ett korrekt kopplat och jordat el‐uttag. El‐sladden som medföljer denna enhet måste kopplas enligt foljande: Fas—Brun Neutral—Blå Jord—Grön/Gul BELANGRIJK VEILIGHEIDS‐VOORSCHRIFT: Deze unit voldoet aan de EN60065 veiligheids‐standaards. Dit apparaat mag niet worden blootgesteld aan vocht. Vanwege het risico dat er druppels in het apparaat vallen, dient u er geen vloeistoffen in bekers op te plaatsen. Voor een veilig gebruik en om het gevaar van electrische schokken en het risico van brand te vermijden, dienen de volgende regels in acht te worden genomen: Controleer of de spanningscaroussel op het juiste Voltage staat. Gebruik alleen zekeringen van de aangegeven typen en waarden. Aansluiting van de unit alleen aan een geaarde wandcontactdoos. De netkabel die met de unit wordt geleverd, moet als volgt worden aangesloten: Fase—Bruin Nul—Blauw Aarde—Groen/Geel ® Dolby LM100 Broadcast Loudness Meter User’s Manual...
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Page 7: Table Of Contents
Table of Contents Chapter 1 Introduction 1.1 LM100 Front and Rear Panels ......................2 1.2 LM100 Configurations ........................2 Chapter 2 Getting Started 2.1 Unpacking and Inspection ....................... 3 2.2 Safety Information ........................... 3 2.3 Mounting............................4 2.4 Rear-Panel Connections ......................... 4 2.4.1 Analog Inputs .......................... - Page 8 5.4 Channels for Measurement ......................38 5.5 Alarms............................38 5.6 System Log............................39 5.7 Serial Ports ............................40 5.8 GP I/O Port ............................41 5.9 NTSC Model ..........................41 5.10 LTC Model ...........................41 ....................43 Appendix LM100 Specifications ® viii Dolby LM100 Broadcast Loudness Meter User’s Manual...
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Page 9: List Of Figures
Listening Icon Display before Dialogue Intelligence Computes........... 35 Figure 5-2 Short Term Measurements....................36 Figure 5-3 Short Term Dialogue Level History Example Using LM100 Logging Features ....37 Figure 5-4 System Log Status Menu ....................40 Figure 5-5 System Log Entry Detail Display ..................40 ®... -
Page 11: List Of Tables
Table 5-1 Application Examples for Short Term and Infinite Term Measurement Methods ....37 Table 5-2 Available Alarm Types......................38 Table 5-3 Alarm Output Port......................... 39 Table 5-4 GP I/O Port ........................... 41 ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 13: Chapter 1 Introduction
features a revolutionary measurement technology capable of quantifying the subjective loudness of speech in broadcast programming. This technology has been specifically developed to analyze the input signal and make measurements only when dialogue is present. Quantifying the dialogue level simplifies a crucial step in broadcasting. When switching between programs, most home listeners adjust their television volume controls in an effort to achieve consistency in dialogue levels between programs. By properly quantifying the level of dialogue, you can ensure that the Dolby Dialogue Level metadata parameter is accurate. Setting this parameter accurately standardizes the loudness for all programs, eliminating the need for home listeners to adjust the volume. For details on Dolby metadata, see A Guide to Dolby Metadata, available at www.dolby.com/assets/pdf/tech_library/18_Metadata.Guide.pdf . The LM100 measurement algorithms yield more consistent results than either PPM or VU meters with sources that primarily contain dialogue. They comply with either ITU‐R BS.1770 Annex 1 or IEC 60804. The LM100 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 ) parameter value within a Dolby Digital or Dolby E program dialnorm by making a direct, objective comparison to the actual measured dialogue level value. The LM100 can determine the unweighted true‐peak level per ITU‐R BS.1770 Annex 2. 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, ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 14: Lm100 Front And Rear Panels
• Dedicated controls to pause and reset the measurement function • LEDs that indicate fault, error, and audio alarm conditions • A headphone jack with volume control For detailed information on the LM100 front panel, see Chapter The rear panel provides the following: • AES3 digital input connectors with loop‐through • Two balanced analog inputs on combination XLR/quarter‐inch TRS connectors • A pair of RCA connectors for confidence and signal‐presence monitoring of the selected source • GPI/O status and alarm connectors For detailed information on the LM100 rear panel, see Chapter Note: The LM100 front‐ and rear‐panel serial interfaces provide remote control, status logging, and a means for updating software. LM100 Configurations The unit is available in the following two configurations: • The LM100‐LTC includes a linear timecode input that allows signal‐condition alarm events to be logged against an external timecode (LTC) input. • The LM100‐NTSC includes an RF input specifically for CATV and NTSC “off air” television measurement applications. The RF tuner also includes a composite video output. The RF input replaces the timecode input, therefore logging in this version is referenced to the internal clock. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 15: Chapter 2 Getting Started
• Using the Default Measurement Display • Using the Dialogue and All Display • Installing the Remote Software Unpacking and Inspection Before unpacking the unit, inspect the outer carton for shipping damage. If the carton shows damage, inspect the unit in those areas. Several essential items are provided with the unit, including: • Power cords for use in the United States and Continental Europe • A CD‐R containing the Universal Remote application and its documentation • A bag containing 75 ohm terminators, rackmount screws and washers, and a serial connection cable for the front‐panel RS‐232 port • Safety notices • Warranty information—fill out the warranty card and return it to Dolby Laboratories Note: To maintain your eligibility for software upgrades, register your product on the www.dolbysupport.com software upgrades page at Safety Information Before you begin installing your LM100, refer to the Important Safety Instructions on page iii. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 16: Mounting
GP I/O Remote RS-485 Remote RS-485 Rear-Panel Audio and Data Ports Figure 2-1 2.4.1 Analog Inputs Each analog audio input jack accepts either a male XLR connector or a quarter‐inch TRS connector. The maximum input signal level is +22 dBu. 2.4.2 Analog Outputs The and are provided on standard RCA connectors for Left Right Analog Outputs confidence monitoring of the active audio program. They carry a two‐channel audio signal automatically downmixed from a multichannel signal if necessary. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 17: Digital Inputs
GPI/O Specific LM100 status information and control inputs are provided through the port. GP I/O You can use a GPI/O device with the LM100 without setting it to Remote mode. For details, see Section 5.8. 2.4.7 NTSC The LM100‐NTSC includes a standard port. Use a standard 75 ohm RF cable to RF Input connect the LM100 to either a cable TV input or an antenna receiving off‐air signals. The LM100‐NTSC is a standard composite video signal available on a female Video Output BNC connector. It allows confidence monitoring of the video for the active program. 2.4.8 The LM100‐LTC includes a port that can read linear timecode per the Timecode Input SMPTE 12M specification. 2.4.9 Power Warning: Before applying power, check the main fuse using the following procedure. The LM100 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. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 18: Internal Fuse
Internal Fuse The switching power supply contains a separate fuse. Most fault conditions should be protected by the main fuse. If you find it necessary to replace the internal fuse, be certain to replace it with a fuse of the same type and rating as printed on the switching power supply board. No Power Switch There is no power switch on the LM100. To apply power, connect the power cord to a live outlet. Using the Default Measurement Display As soon as power is applied, the LM100 is ready to measure. The unit uses Dialogue ™ Intelligence to compute Infinite Term loudness for all channels measured according to ITU‐R BS.1770 Annex 1, and the loudest true‐peak level computed according to ITU‐R BS.1770 Annex 2 for any current channel. True‐peak measurements have an instant attack, a peak hold of 0.75 second, and a constant decay of 12 dB ± 2 dB per second following the peak hold. Figure 2‐2 shows an example screen. Figure 2‐2 Default Measurement Display Example Figure 2-2 ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 19: Using The Dialogue And All Display
Installing the Remote Software We strongly recommend that you continue on to install the remote management software. Universal Remote provides quick access to the LM100ʹs functions, including some that are not available from the unit front panel. Use of Universal Remote allows the LM100 to be located in another room or at a distance from the operator. While Universal Remote is in operation, the button on the front Remote panel of the unit is lit and access to the setup menu via the front‐panel buttons is disabled. Note: The RS‐232 specification limits serial cable length to 50 feet. Using low capacitance cables can, however, extend this limit up to 147 feet. Refer to the specification for exact information. 2.7.1 System Requirements Universal Remote can be run on a PC that meets these minimum requirements: ® • 166 MHz Pentium processor • 32 MB RAM • 10 MB available hard drive storage • Super VGA video card with at least 800 × 600 resolution ™ ™ • JRE 1.5 or later installed ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 20: Installing The Software
You can change the default remote operation settings from the unit front panel on the System Settings portion of the Setup menu. Follow these steps. At the main status screen, press the button. Setup At the main Setup menu, press until the LCD second line reads System Settings (seven times). Press Enter Press . The second line reads Baud Rate. Press if you need to change it. Enter Then press until the baud rate you wish to use appears in the display. Then press to return to the main system settings menu. Press twice. The second line reads Unit Address. Press if you need to Enter change it. Enter a new unit address. 2.7.5 Beginning and Ending Remote Operation To begin remote operation, on the LM100 unit front panel, press and release once so Shift that the button lights up, then press . While in Remote mode, the front‐panel LED labeled ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 21: Starting The Universal Remote Software
Installing the Remote Software glows green, and setup commands cannot be made from the unit front panel. The Remote status menus continue to display accurate unit status in Remote mode. To end remote operation, press then again. Shift 2.7.6 Starting the Universal Remote Software ™ To start the remote software in Windows Go to Programs > Universal Remote. Click Universal Remote. The machine displays the main application screen shown in Figure 2‐4. Figure 2‐4 Universal Remote Main Screen Figure 2-4 Connect to one of your configured devices to begin work. See the online help for detailed information on using the Universal Remote effectively. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 23: Chapter 3 Front-Panel Controls
Shift Shift alternate function, press the LM100 button and then press the corresponding button. Shift The button lights when pressed, and remains lit until you press a button with an Shift associated shift command, press again, or press the LM100 button. Shift Remote Pressing scrolls through the status menus. In setup menus and the Dolby E Metadata and Dolby Digital Metadata status menus, when selecting an option, pressing returns the display to the next‐higher menu level without activating your selection. Pressing then activates remote operation. The button is lit, and the unit remains in Shift remote operation until the same combination is pressed again. In the Headphone Volume or Brightness menu, pressing decreases the setting incrementally. Pressing moves the selection from the current menu option to the one above. In the Headphone Volume or Brightness menu, pressing increases the setting incrementally. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 24: Special Function Button Combinations
and are dedicated controls for measuring loudness. For details on loudness Reset Pause measurement functions, see Section 5.1. 3.1.2 Special Function Button Combinations In special cases, you may need to reset the LM100 or upgrade the firmware. Table 3‐1 shows the button combinations to press for each of these special functions. Special Function Button Combinations Table 3-1 Function Action/Result Press Shift, Esc and simultaneously to reboot the LM100. Hardware Reset During reboot, press and hold Setup; the status display Firmware Upgrade provides you with the option of upgrading the unit firmware or completing the boot sequence. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 25: Led Indicators
Dolby Digital. Input is missing. Change the input selection or check No Input the input source. The input is a valid Dolby E signal, but the Check the channel mode configuration Invld Ch Md metadata indicates more channels than exist in parameter within the selected (Invalid channel mode) the selected program. program in the Dolby E stream. The Dolby E metadata RF overmodulation Check the Dolby E stream. RF Ov Prot protection parameter is enabled in one or more (RF overmodulation protection of the programs. enabled) Dolby E metadata does not contain Dolby Check the Dolby E stream. No DD Md Digital metadata. (No Dolby Digital metadata) ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 26: The Rs-232 Connection
Corrective Action The unit is uncalibrated. Return the unit to the factory for Uncal calibration. (Uncalibrated) The RS-232 Connection The port can be used for software upgrades, to connect to a custom‐built Remote RS-232 remote‐control software interface, or to send LM100 system log file entries to any device that can receive ASCII text strings using RS‐232 protocol. For details, see Section 5.7 Serial Ports. Note: Connecting a cable to this port disables the rear‐panel port. Remote RS-485 The Headphone Connection You can connect headphones to the LM100 for confidence monitoring of the active program. To adjust headphone volume, press the front‐panel button combination Shift then Enter. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 27: Chapter 4 Menus
To view a status menu when a setup Setup. menu is displayed, press the button combination: then Shift Setup. Note: If you do not press a front‐panel button within the interval set on the Screen Saver Timeout setup menu, the LM100 displays a screen saver that inverts the display. Pressing any front‐panel button returns the screen to normal. The Status Menus The status menus display the current measurement values and active settings for a selection of setup parameters and the condition and content of input signals. The main status screen shows the current measured loudness value and information regarding the input stream status. You can display additional input stream status information by pressing the and buttons to scroll through the other status menus. 4.2.1 Main Status Screen When you power on the LM100, the main status screen appears. It is the most important LM100 screen, as it shows the measured loudness values. This menu is usually divided into three sections, although one display option divides the screen into two sections. Examples of the main status screen appear in Figure 4‐1, Figure 4‐2, and Figure 4‐3. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 28: Figure 4-1 Main Status Screen Receiving A Dolby Digital Stream In Default Mode
Main Status Screen with No Input Signal Figure 4-3 Input Identifier The input stream is identified in the upper left section of the display. When the source is Dolby Digital, the channel mode appears. If an LFE channel is included, it is indicated by an L to the right of the channel mode. Immediately next to the channel mode, the data rate in kbps appears. When the source is Dolby E, the screen displays the program configuration, the bit depth of the Dolby E stream, and the currently selected program, as shown in Figure 4‐4. Figure 4‐4 Main Status Screen when Receiving a Dolby E Stream Figure 4-4 When the source is PCM, the sample rate appears, as shown in Figure 4‐5. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 29: Figure 4-5 Main Status Screen When Receiving A Pcm Signal
Main Status Screen when Receiving an RF Signal Figure 4-7 Measurement Timer If the LM100 is in Infinite measurement mode, a time counter appears in the lower left portion of the screen, as shown in Figure 4‐1. This indicates the amount of time that has elapsed since the measurement was reset. If you pause the measurement, that area flashes paused, and the button also flashes. Pause When the LM100 is in Short‐term mode with Dialogue Intelligence™ enabled, the time counter appears when dialogue is not detected, indicating the amount of time elapsed since dialogue was last detected. While dialogue remains undetected, the measurement value in the center section flashes and a second value appears at the bottom of the center section. That value shows the current non‐dialogue‐based measurement; the flashing value shows the last valid dialogue‐based measurement, and the counter shows the time elapsed since the dialogue‐based measurement stopped. When dialogue‐based measurement resumes, the time counter and the second value no longer display. Measurement Displays The remainder of the screen displays information relative to the current measurements. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... - Page 30 ± 2 dB/second following the peak hold. The main status screen also provides different display modes. Press to scroll through Enter these different modes on the right side of the screen. When measuring Dolby Digital or Dolby E signals, the far right section of the default screen shows the setting for the dialnorm value contained in the metadata stream. If you press , this section of the display shows the largest peak value. If you press Enter again, the Enter screen displays only a single, larger magnification of the loudness measurement. Pressing one more time displays the default screen where the dialnorm value appears on the Enter far right. If the LM100 is in Infinite mode with Dialogue Intelligence enabled and dialogue is not detected, the measurement value holds and begins to flash until the unit detects dialogue again. In Short‐term mode with Dialogue Intelligence enabled, if dialogue is not detected, the measurement value flashes and a second value appears at the bottom of the center section, as previously discussed. That value shows the current non‐dialogue‐based measurement; the flashing value shows the last valid dialogue‐based measurement, and the time counter in the lower left section shows the time elapsed since the dialogue‐based measurement stopped. When dialogue‐based measurement resumes, the time counter and the second value no longer appear. When you select the Analog input, an additional display mode is now available. This additional mode displays the recommended value for setting the dialogue level parameter in downstream Dolby Digital or Dolby E encoding equipment; this recommended value allows the operator to simply calculate a value when dialnorm measuring analog sources. Figure 4‐8 shows an example of this display. ® Dolby LM100 Broadcast Loudness Meter User’s Manual...
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Page 31: Figure 4-8 Main Status Screen Displaying A Recommended Dialnorm Setting For An Analog Input
4.2.2 Level Meters Figure 4‐9 shows a sample level meter display. This display provides a more familiar PPM‐style meter for each input channel. The meters have an instant attack time and a constant decay of 12 dB/second ± 2 dB/second. Each channel signal is identified at the bottom of the screen. The scale is displayed on the left side and represents LKFS, dBFS, dBu, or dBr, depending on the input signal type and processing mode. Figure 4‐9 Level Meter Displaying a Dolby E 7.1 Input Figure 4-9 Press to zoom in on the upper portion of the scale. Enter 4.2.3 Metadata Status The metadata status menu enables you to check the settings of key metadata parameters in either a Dolby E or Dolby Digital input stream. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 32: Digital Input Status
Level, Dialnorm, Phase Error, and Digital Input Loss. For the LM100‐NTSC, there are two additional alarms: RF Overmodulation and RF Input Loss. To reset the alarm count on a single alarm type, press to view the Alarm Detail Enter menu, then again to reset the count to zero. Enter To reset all alarm counts, select Clear All Alarms and press A confirmation Enter. prompt appears. Press to confirm the global reset, or to exit the prompt without Enter resetting the counts. Alarm statistics can also be sent as a text log to a device connected to a serial port. For details, see Section 5.5. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 33: System Log
The Main Setup Menu In the Main Setup menu, you can configure the LM100 to suit your needs. When viewing a status menu, or any setup menu, pressing displays the Main Setup menu. If any Setup setup menu display is unchanged for five minutes, the display reverts to the Main Setup menu. 4.3.1 Measurement Control In the Measurement Control menu you can configure the following: • Channel Select • Measurement Method • Dialogue Intelligence • Measurement Type The proper settings are determined by factors such as whether the LM100 is being used in a live or postproduction environment, for multichannel or stereo material, for quality control or off‐air monitoring, or for aligning the loudness of multiple services. It is important that you understand how to set these parameters. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 34: Input Control
Dolby E Program • AES3 Channel Select mode • Analog Input Cal (calibration) settings Input Source In the Input Source menu, you can select the input to use for a measurement. A special mode (RF/Digital) expects RF input by default, but automatically switches to digital input if a valid Dolby E or Dolby Digital signal is present on the Digital Input connector. This mode is used when the LM100‐NTSC is simultaneously connected to the digital audio and the channel 3/4 remodulated outputs of a digital cable set‐top box. Thus, when the set‐top box is tuned to an analog tiered service, the unit measures the signal directly from the RF tuner; when the set‐top box is tuned to a digitally tiered service, the unit autodetects the presence of a Dolby Digital stream from the S/PDIF output on the digital set‐top box, and measures it. Decode Format Use the Decode Format menu to select the bitstream type you want the LM100 to decode. This parameter is normally set to Autodetect. However, if required, you can override this setting and specify that the LM100 decodes only one bitstream type. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 35: Analog Input Calibration
Table 4-1 Reference Analog Loudness Ref Volts Digital Loudness Ref SMPTE RP155 +4 dBu 1.23 V –20 dBFS EBU R68 0 dBu 0.775 V –18 dBFS RF Tuning Mode This feature is available only on the LM100‐NTSC. Use the RF Tuning Mode menu to select the frequency plan (Off-Air, Cable STD, Cable HRC, or Cable IRC) used for tuning RF signals. RF Channel This feature is available only on the LM100‐NTSC. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 36: Monitor Control
DAC on Non-Audio The DAC on Non-Audio menu controls whether a digital input signal flagged as non‐audio (via the AES3 Channel Status Byte 0 bit 1) is muted or sent to the headphone and . Analog Outputs PCM Latency The PCM Latency menu allows the user to set the latency from the to the Digital Input for a PCM signal. Analog Outputs 4.3.4 Alarm Control The LM100 alarm capabilities are among its most useful and versatile functions, as described in Section 5.5. Use the Alarm Control menu to set the parameters that trigger alarms. Input Clipping Use the Input Clipping menu to configure the parameters of the input clipping alarm. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 37: Table 4-2 Input Clipping Alarm Parameters
Use the RF Overmodulation menu to enable or disable the overmodulation alarm for RF input signals. When enabled, any signal that modulates the aural carrier by more than 101 percent triggers the alarm. Digital Loudness Reference Use the Digital Loudness Ref menu to set the reference loudness level for digital input signals. This reference level is used by the over/under threshold alarms. Analog Loudness Reference Use the Analog Loudness Ref menu to set the reference loudness level for analog input signals. This reference level is used by the over/under threshold alarms. Note: When the Analog Loudness Ref setting is not zero, measurement for the analog input is expressed in dBr. When the setting is zero, the measurement is expressed in dBu, reflecting that 0 dBu = 0.775 V RF Loudness Reference This feature is available only on the LM100‐NTSC. Use the RF Loudness Ref menu to set the reference loudness level for RF sources. This reference level is used by the over/under threshold alarms. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 38: Table 4-3 Over Level Alarm Parameters
Under Level Alarm Parameters Table 4-4 Menu Item Controls Range Enables or disables the alarm. Enabled/Disabled Alarm The loudness threshold for the alarm. The alarm 1 to 31 dB Threshold triggers if the measured loudness value falls below the loudness reference minus the threshold for the duration specified in Time The duration of the under‐level condition required 0 to 300 seconds Time to trigger the alarm. Dialnorm Threshold The Dialnorm Threshold alarm is triggered when the measured loudness value of the input signal deviates from the value already carried within the Dolby E or Dolby dialnorm Digital input stream. This alarm is useful for identifying Dolby E and Dolby Digital bitstreams with incorrect dialogue level values. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 39: Table 4-5 Dialnorm Threshold Alarm Parameters
The DE RF Overmod Protect alarm is triggered when a Dolby E signal with the RF Overmod metadata field enabled is detected. Use the menu to enable or disable the alarm. Track Measurement You can control all the alarm counters using the front‐panel button or the GPI/O port. Reset If you set Track Measurement to Enabled, pressing the button clears all the alarm Reset counters simultaneously, as well as resetting the measurement. If you disable this setting, pressing has no effect on the alarm counters. Reset Alarm Output Polarity When an alarm is triggered, the LM100 generates a pulse on the associated port pin, Alarm as shown in Table 5‐3, as well as on the Alarm pin on the port. Use the Alarm GP I/O Output Polarity menu to set the polarity for the alarm outputs to either positive or negative. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 40: User Presets
Enter. The old preset name disappears. Use the arrow buttons to highlight each character in the new preset name, pressing after highlighting each character. Enter When the name is complete, highlight OK, then press Enter. The confirmation prompt in Figure 4‐11 appears. Figure 4‐12 Figure 4-11 Save Preset Prompt If the new preset name is correct, press to save the preset with that name. If not, Enter press and return to step 1. Esc, When the new name is saved, the display reverts to the main status screen, briefly showing the message in Figure 4‐12. Figure 4‐13 Figure 4-12 Preset Confirmation Message ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 41: System Log
Periodic Loudness The system log can store the current measured loudness value at regular (that is, periodic) time intervals, as set in the Periodic Loudness menu. This allows you to use the LM100 to simultaneously track and log the changes in the loudness of programs or services over many hours or days. Note: When measuring in Infinite mode, additional settings appear in the Periodic Loudness menu, which enables the measurement to automatically reset at the same time interval as the periodic measurement itself logs. For example, if you select 30 Seconds with Reset, the LM100 generates a “periodic loudness” system log entry based on the integrated level for the past 30 seconds, and then resets the infinite measurement before continuing. Metadata Log When this is enabled, the metadata parameters shown below within a Dolby E or Dolby Digital bitstream are added to the system log. This is done whenever a Dolby E or Dolby Digital bitstream is first detected, and subsequently when any of these parameters change value. Dolby Digital Channel Mode Dolby Digital LFE Channel Dolby Digital Data Rate Dolby Digital Dialogue Level Dolby E Program Configuration Dolby E Bit Depth Dolby E Frame Rate Dolby E Px Channel Mode Dolby E Px LFE Channel Dolby E Px Dialnorm ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 42: System Settings
Clear System Log When this is enabled, you can manually delete all entries in the system log. 4.3.7 System Settings The System Settings menus allow you to configure several unit behaviors. Remote Baud Rate This setting controls the speed (baud rate) of the RS‐232 and RS‐485 serial ports. Remote Mode When you select Remote, the LM100 can be controlled from a remote‐control application or device over the serial ports. When you select Logging, the serial ports output each system log entry as an ASCII text string as it is generated. This output can be displayed and stored by any standard terminal application. Unit Name You can name your unit using up to 12 characters. This is useful for identifying the LM100 from remote‐control applications. To enter a name, go to the Unit Name menu and use the procedure for text entry, as described in Section 4.3.5. Unit Address The unit address allows each LM100 to be uniquely identified when using a software remote‐control application over the serial connection, using either the or the RS-232 RS-485 ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 43: Screensaver Timeout
The Main Setup Menu connection. You can connect more than one LM100 to the same RS‐485 link, provided that each unit is assigned a unique address. Time/Date Use the Time/Date menu to set the internal real‐time clock. Screensaver Timeout After a defined period of inactivity, the LM100 applies a screen saver to prolong the life of the display screen. Use the Screensaver Timeout menu to set this period of inactivity. True Peak Channel ID Choose On to identify the channel in which the measured peak on the display occurred. Choose Off not to identify it. Enable Dialogue and All Display Choose Enable to display Dialogue and All measurements when the LM100 is making Infinite measurements of the ITU‐R type with Dialogue Intelligence on. Choose Disable to prevent this display. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... - Page 44 Menus ® Dolby LM100 Broadcast Loudness Meter User’s Manual...
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Page 45: Chapter 5 Features
The updated version of the LM100 also can use the new recommended algorithm published by the International Telecommunication Union’s Radiocommunication sector (ITU‐R) for use in estimating program loudness levels of digital broadcasting: ITU‐R Rec. BS.1770—Algorithms to Measure Audio Programme Loudness and True‐Peak Audio Level. This new algorithm also estimates loudness by computing the frequency weighted energy average over time similar to Leq(A), and produces a single value representing the overall loudness level. The core ITU‐R algorithm, however, is based on two filters in cascade : a prefilter (a high‐frequency shelving‐type filter) followed by the revised low B‐weighting filter (a type of highpass filter): Leq(RLB). Speech‐based measurements produced with the LM100’s Dialogue Intelligence feature enabled—using either Leq(A) and ITU‐R BS.1770—have shown that, while BS.1770 is slightly more accurate than Leq(A), the average difference when measuring dialogue is fairly small. Comparison of measurements made by the two methods suggests that the average absolute error (AAE) has decreased by only 0.27 dB and the maximum absolute error (MAE) has decreased by 1.3 dB for the samples used in this comparison. Therefore engineers may be uncertain about the particular benefits of the new ITU‐R algorithm. The answer can be derived in part from the findings of an ITU study group who determined that the BS.1770 algorithm was more effective than Leq(A) in determining appropriate levels for non‐speech–based material, such as music and soundtrack material. This improvement would be most applicable in concerts and other types of music programming are common, where LM100 users typically disable Dialogue Intelligence. Within broadcast programming the dialogue levels are especially important when considering how to determine the subjective loudness of a program. Research shows that most listeners at home use their volume controls in an effort to keep the dialogue levels uniform as they switch through multiple channels and as they listen through program‐to‐program and/or program‐to‐commercial transitions. It therefore follows that if listeners at home base their loudness judgment on the level of dialogue, then a loudness meter would certainly benefit from an algorithm that mirrors this behavior. Dialogue Intelligence in the LM100 provides exactly that feature, as described in Section 5.2. Leq(A) uses only a single frequency weighting filter. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 46: Measuring Digital Sources
twice from the main status screen). This can be useful when Enter dialnorm setting the parameter value prior to encoding the program for digital dialnorm distribution via Dolby E or Dolby Digital. This recommended value automates the process of calculating a value when measuring analog sources. The calculated (that is, dialnorm derived) value is based on the analog input calibration. See Figure 4‐8. Analog measurements, by default, are based on the dBu scale, or on a relative scale (expressed as dBr) if the analog calibration setting is not 0 dBu. 5.1.3 Measuring RF Modulated Sources When the is selected and a particular channel is tuned, the default main status RF Input screen indicates the measured loudness value side by side with the unweighted peak value. Measurements in the RF domain are referenced to 100 percent modulation of the monophonic sound carrier (25 kHz peak deviation) and are expressed in dBr. Dialogue Intelligence Dialogue Intelligence allows the LM100 to automatically base its measurement on the portions of the input signal that contain the characteristics of dialogue. This powerful feature provides users at all skill levels with the capability to easily quantify the level of dialogue within broadcast programs. By combining Dialogue Intelligence with extensive ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 47: Measurement Methods: Short Term Vs. Infinite Term
Figure 5-1 When you enable Dialogue Intelligence, the measurement is based solely on the portions of the input signal recognized as having the characteristics of speech. Portions of the input signal that do not primarily contain the characteristics of dialogue are not included in the measurement value. Note: The Dialogue Intelligence algorithm is designed to return a dialogue‐based measurement value only when this input signal primarily contains the characteristics of dialogue. Therefore, on rare occasions, the algorithm may ignore a section of the program that contains dialogue but may also be coincident with other types of signals and spectra, such as music or effects. This behavior increases the accuracy and confidence of the dialogue‐based measurement value. Measurement Methods: Short Term vs. Infinite Term The LM100 has two methods of operation relating to the measurement period, Infinite Term and Short Term. This section describes the behavior of both. Infinite Term Method Infinite measurements cover the entire period since the measurement was reset. Both ITU‐R and Leq(A) measurements are available using the Infinite Term method. Enabling Dialogue Intelligence allows you to simply quantify all the sections of the program that contain only dialogue and use the ending measurement value for analysis and normalization. This value is also commonly used to set the dialogue normalization parameter within Dolby Digital and Dolby E bitstreams. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 48: Figure 5-2 Short Term Measurements
Short Term Method Short Term method displays a measurement value for the previous ten‐second period as a sliding window. For example, the first measurement value displayed corresponds to the – 10 seconds time interval, the next to the 1 – 11 seconds time interval, the next to the 2 – 12 seconds time interval, and so forth, as shown in Figure 5‐2. Figure 5‐2 Short Term Measurements Figure 5-2 As the Short Term measurement only considers the last ten seconds of program material, the measurement value has the potential (depending on the program) to be much more dynamic than that measured in Infinite mode. (Highly processed channels and programming will most likely not exhibit this type of behavior.) The benefit of this measurement method is that it allows the operator to see short‐term variations within a program in loudness level or in dialogue level when Dialogue Intelligence is enabled. Many skilled audio operators prefer to use the Short Term measurement, as they find the information on near‐term dynamics to be very useful when mixing or producing a program and they are capable of managing overall program loudness by reading the Short Term measurement. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 49: Figure 5-3 Short Term Dialogue Level History Example Using Lm100 Logging Features
5‐3 clearly reveals an hour when speech levels were elevated (~5 dB on average), whereas the programming that preceded and followed this particular program clearly had lower speech levels. Figure 5‐3 - 10 - 15 Ti m e Short Term Dialogue Level History Example Using LM100 Logging Features Figure 5-3 Each data point represents an individual speech measurement. Table 5‐1 shows application examples that best utilize Short Term and Infinite Term methods. Application Examples for Short Term and Infinite Term Measurement Methods Table 5-1... -
Page 50: Channels For Measurement
The measured loudness level falls below the user‐defined threshold for Under Level Loudness below threshold a user‐defined duration. This can be used as a silence alarm. Digital AES3 input is required but missing. Digital Input Loss The value carried within the Dolby E or Dolby Digital Dialnorm Threshold dialnorm bitstream input differs from the user‐defined threshold for a user‐defined duration. The stereo signal’s Left and Right channels are out of phase. Phase Error The DE RF Overmod metadata field is enabled. DE RF Ov Protect Dolby E RF overmodulation protection Use the Alarm Control setup menu to control the alarm parameters, as described in Section 4.3.4. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 51: System Log
19 Feb 2003 13:50:30 | 2002 | Measurement Pause | Peak: -3.0 dB 19 Feb 2003 13:50:32 | 2003 | Measurement Resume | 19 Feb 2003 13:51:19 | 3002 | LM100 OK | 19 Feb 2003 13:51:34 | 4000 | Dolby Digital Channel Mode | 3/2 ... -
Page 52: Serial Ports
Figure 5-5 Serial Ports You can use the rear‐panel port or the front‐panel port for Remote RS-485 Remote RS-232 software upgrades, to connect to a custom‐built remote‐control software interface, or to send system log events to any device that can receive ASCII text strings through the remote interface cable you connect to the LM100. Note: The port is deactivated if a cable is connected to the Remote RS-485 Remote RS-232 port. For any use, the settings on the System Settings menu must match the connected computer, as described in Section 4.3.7. To generate a text‐based error log to a remote device, set Remote Mode to Logging. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 53: Gp I/O Port
0 = Paused Running 1 = Running — Signal Ground To be recognized, input signals must be asserted for at least 50 ms. The pin 2 and pin 3 functions are provided only on the LM100‐NTSC. Each time either of these pins is grounded, the RF channel number increases incrementally (pin 2) or decreases incrementally (pin 3) by one. If the input remains grounded for more than 500 ms, the RF channel number increases or decreases continuously until the pin is released. Pins 4, 5, and 6 duplicate the functions of the front‐panel and buttons and the Pause Reset LED, respectively. Alarm NTSC Model The LM100‐NTSC enables you to monitor program audio from either cable or off‐air sources using the This allows you to use the LM100 on program material in its RF Input. final delivery format. 5.10 LTC Model The LM100‐LTC receives linear timecode at rates of 23.98, 24, 25, 29.97, and 30 Hz, and supports drop‐ and non‐drop‐frame modes. You can set up the system log to record events by time of day or by timecode stamp by using the System Log setup menu. ® Dolby LM100 Broadcast Loudness Meter User’s Manual... -
Page 55: Appendix Lm100 Specifications
Digital Audio Input BNC female connector with loop‐through, 75, unbalanced, AES‐3id (SMPTE 276M) ® Formats supported: PCM data up to 24 bits; Dolby E data supported in 16‐, 20‐, and 24‐bit modes at 48 kHz; Dolby Digital (AC‐3) data at 32, 44.1, and 48 kHz sample rates Analog Audio Inputs ® Two Neutrik combination XLR/quarter‐inch TRS connectors, electronically balanced Maximum input level: ~ +22 dBu Input impedance: 10k ohm User‐definable nominal operating levels Analog Audio Output Two RCA‐type connectors, unbalanced, stereo Maximum output level: 2 V into a 10k ohm load per IEC 61938 RF Input Only on the LM100‐NTSC F‐type female connector with internal 75 ohm termination Tuner frequency range: 55.25 to 801.25 MHz Supports BTSC‐encoded stereo signals Selectable CATV or “off‐air” modes CATV mode supports the Cable Television Channel Identification Plan per EIA 542 (User‐selectable: Standard, HRC, or IRC channel identification plans) ® Dolby LM100 Broadcast Loudness Meter User’s Manual... - Page 56 Alarm Port 9‐pin female D‐connector, 0–5 V TTL level User‐definable alarms: input clip detection, modulation overload, loudness above threshold, loudness below threshold (silence), threshold, and AES input loss dialnorm General Purpose Input/Output (GP I/O) Port 9‐pin female D‐connector, 0–5 V TTL level Measurement/Analysis System Log 480 events stored in internal nonvolatile RAM (Unlimited event storage and retrieval via serial ports) Power Requirements 90–264 VAC, 50–60 Hz, auto‐sensing, 15 W maximum; unit designed to operate from a centrally switched power source Dimensions and Weight 1‐U rackmount: 44 × 483 × 375 mm (1.75 × 19 × 14.75 inches) Net: 2.5 kg (5.5 lb) Environmental Conditions Operating: 0°C to 50°C (32°F to 122°F), natural convection cooling, 0% to 98% relative humidity (noncondensing) Nonoperating: –20°C to +70°C (–4°F to +158°F) ® Dolby LM100 Broadcast Loudness Meter User’s Manual...
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