Dolby® Professional Loudness Solutions Information for Prospective Licensees Issue 3
Table of Contents Introduction.................................................................................. 1 Technology Overview................................................................ 2 License Agreement.................................................................... 3 License Fees and Royalties..................................................... 4 Obtaining a License...................................................................
Introduction Broadcasters and content producers use Dolby® Professional Loudness solutions to help ensure consistent audio loudness levels. Because differences in levels provoke a large number of consumer complaints, all steps in the broadcast production chain require tools to help maintain uniformity.
Technology Overview The Dolby® Professional Loudness Metering solution combines the use of standards-based loudness estimation algorithms with Dolby Dialogue Intelligence™ technology. Supported algorithms are those most prominently in use worldwide: Leq(A), ITU-R BS.1770-1, ITU-R BS.1770-2, and EBU R 128.
License Agreement If you wish to develop products incorporating Dolby Professional Loudness Metering and Correction solutions, you are required to ® enter into a Dolby Professional Loudness Metering and Correction license agreement with Dolby Laboratories. Once the agreement has been signed and we have tested and approved your product, your license will be activated. (Please note that this document is not such a license or an offer of such.
License Fees and Royalties There is a one-time licensing fee for Dolby Professional Loudness Metering and Correction solutions. The license includes patent, ® copyright, and trademark rights; know-how; and the rights to sell your product to end users. It also includes an appropriate development kit, technical support, and our testing and certifying your products for one year from the time your license is activated.
Obtaining a License To obtain approval of your product incorporating Dolby Professional Loudness Metering and Correction solutions and activate your ® license, you must complete the following steps: 1. Email licensinginquiries@dolby.com and request the Questionnaire for Prospective Dolby Licensees form. This form will be emailed to you as an interactive PDF, which you can fill out onscreen. Please complete the form in English, then submit it to us.
Product Specification for Dolby® Professional Loudness Metering and Dolby Professional Loudness Correction This product specification is in two parts: Part One discusses Dolby® Professional Loudness Metering, and Part Two discusses Dolby Professional Loudness Correction for System and Implementation Licenses.
Tools or test materials provided as part of the deliverables may be used only for internal testing and development of the Licensed Product and not for any other purpose. Tools or test materials may not be used as part of the Licensed Product itself or provided to or used by any third party other than for the test development of the Licensed Product.
• If the Licensed Product is a file-based transcoder product, the provided test signals in PCM or WAV format are also supplied as Dolby Digital, Dolby Digital Plus, and Dolby E encoded files. The output encoded file will be checked for proper setting of metadata. • If the Licensed Product is a file-based transcoder or encoder product, proper setting of the dialogue-normalization value after loudness estimation is required and will be tested for in the compressed output file.
• For metering products, adherence to the requirements outlined in EBU Tech 3341 is recommended.5 {{ A reset control for real-time measurement products is required. Sample Rate All loudness-estimation products must support 48 kHz. Support for 32 kHz and 44.1 kHz is optional. Bit Depth Bit depths of 16, 20, and 24 bits are required to be supported, with a default of 24 bits.
Real-time functionality is as follows: • Real-time update of the dialnorm, DRC, and CRC bitstream parameters of Dolby Digital and Dolby Digital Plus bitstreams, from a previously available loudness measurement Tools or test materials that are provided as part of the deliverables may not be used as part of the Licensed Product itself.
• Dialnorm update: Occasionally, it is necessary to update a Dolby Digital or Dolby Digital Plus stream with a new dialnorm value. This occurs when the loudness of the content has been previously measured or is otherwise known a priori. The dialnorm-update function inserts a new dialnorm-parameter value into a Dolby Digital or Dolby Digital Plus bitstream. This is a one-pass or real-time process.
Licensed Product Requirements Licensed Products must be developed in accordance with the terms in Tables 3 through 19. Table 3 General Requirements and Recommendations Category Specification 1. Logos and Trademarks Complies with the guidelines in the appropriate Dolby logos and trademarks guide. Only the logos and markings specified there are acceptable for inclusion. 2. Core Processing The library object code delivered with the kit cannot be modified. 3.
Table 5 Loudness Metering Mode Parameter Mode Settings Default Loudness metering mode (R) ITU-R BS.1770-2 plus Dialogue Intelligence (R) ITU-R BS.1770-1 plus Dialogue Intelligence (O) ITU-R BS.1770-2 (O) Leq(A) plus Dialogue Intelligence (O) ITU-R BS.
Table 12 Normalization Target Parameter Setting Values Default Setting Normalization target (R) –31 to–8 LKFS/LUFS/dBFS, in 1 dB increments or finer –24 LKFS/LUFS/dBFS R = Required parameter Note: The normalization target parameter is relevant only when the mode is set to Loudness Normalization. This parameter must be disabled or hidden from the user when the mode is set to Bitstream Loudness Correction.
Table 15 File-Based Loudness Correction Logging Log Parameter Description Rate Number of streams (R) Products must report the number of streams found in each file by DPLC. Per file Number of programs (R) Products must report the number of programs found in each stream by DPLC. Per stream CRC counts (R) Products must report the number of CRC checks found (passed and failed) in each stream.
Input and output DRC profiles: Line mode (R) RF mode (R) Input and output: Products must report both the Line mode and RF mode DRC profiles of the input and output bitstream: None, Film Standard, Film Light, Music Standard, Music Light, Speech, or Not Present. Correction (indicator only) (R) Output: Correction indicates the section of parameter values that are DPLC output results.
Dialnorm Update Requirements If implementing dialnorm updating, the requirements in Tables 17 through 19 apply. Table 17 Dialnorm Update User-Interface Parameter Requirements Parameter User-Interface Settings and Description Default Setting dialnorm update mode (R) The two types of dialnorm update: Absolute mode (R) Relative mode (R) Absolute mode dialnorm value (R) (main program) In Absolute mode, this parameter selects the dialnorm value (1–31) to write into the output bitstream.
Table 19 Log Warnings for Dialnorm Update Log Warnings (All Required) Description Partial frame A partial frame was detected in the bitstream. Unsupported frame An unsupported frame was detected. CRC error A CRC error was detected. Input dialnorm changed The input dialnorm changed. Output dialnorm saturated The output dialnorm is saturated. Additional information The input stream contains additional information.
General Licensing Requirements OEM DEVELOPMENT KITS If the Licensed Product is to be an OEM development kit, either as a board or software library, the Licensee will act as an implementer and may sell such Licensed Products only to Qualified Recipients that Dolby has licensed and authorized to receive such Implementations.
Appendix DOLBY PROFESSIONAL PRODUCTS Dolby Laboratories manufactures a variety of professional products ideally suited for broadcast, DVD mastering, and other applications. Dolby DP569 Multichannel Dolby Digital Encoder The DP569 encodes up to 5.1 channels for DTV transmissions and DVD mastering applications.
Dolby Media Producer Software Suite Dolby Media Producer is a suite of professional software that supports all Dolby audio codecs used in mastering DVD-Video and Blu-ray DiscTM formats. It supports multichannel non-real-time encoding and file decoding of Dolby Digital Plus, Dolby Digital, Dolby TrueHD, and MLP LosslessTM formats via an intuitive user interface. The suite comprises six separate software products, including Dolby Media Encoder, Dolby Media Decoder, Dolby Media Tools, and Dolby Media Meter.
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