1、 Table of contents Foreword Introduction 1 Scope 2 Normative references 3 Parameter values Annex A Bibliography Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United Sta
2、tes of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in t
3、heir work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices. SMPTE Standard SMPTE 428-2 was prepared by Technology Committee DC28
4、. Introduction This standard addresses interoperability of equipment used to deliver audio in digital cinema theaters by defining the sample rate, bit depth, channel count and reference level of the digital audio. Page 1 of 3 pages SMPTE 428-2-2006 SMPTE STANDARD D-Cinema Distribution Master Audio C
5、haracteristics Copyright 2006 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved August 16, 2006 SMPTE 428-2-2006 Page 2 of 3 pages 1 Scope For interoperability of digital cinema equipment used to create an Audio D-Cinema Distrib
6、ution Master. The necessary characteristics of digital audio to be specified are bit depth, sample rate, minimum channel count, and reference levels. 2 Normative references The following standard contains provisions which, through reference in this text, constitute provisions of this standard. At th
7、e time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent edition of the standard indicated below. AES3-2003, AES Recommended Practice for D
8、igital Audio Engineering Serial Transmission Format for Two-Channel Linearly Represented Digital Audio Data 3 Parameter values 3.1 Bit depth The bit depth shall be a maximum of 24 bits per sample. Material having other bit depths shall be justified to the most significant bit (AES3, clause 4.1.1). T
9、he audio sample word shall be linear 2s complement representation as defined in AES3, clause 4.1.1. 3.2 Sample rate Irrespective of the associated image frame rate or rates, the delivered audio sample rate contained within the D-Cinema Distribution Master (DCDM) shall be either forty-eight thousand
10、samples per second per channel, commonly expressed as 48.000 kHz, or ninety-six thousand samples per second per channel, commonly expressed as 96.000 kHz. Audio sample rate jitter shall be as specified in AES3. NOTE The called out sample rates are an average over time. Instantaneous deviation of the
11、 sample rates from their average (jitter) affects the quality of the audio output in digital-to-analog conversions and so must be considered in implementation designs. 3.3 Channel count The digital cinema distribution master (DCDM) shall support a channel count of sixteen full-bandwidth channels. No
12、t all sixteen channels need be used on any given title. 3.4 Reference level, Digital Digital inputs and outputs shall have a reference level of 20 dB FS. SMPTE 428-2-2006 Page 3 of 3 pages Annex A (informative) Bibliography AES5-2003, AES Recommended Practice for Professional Digital Audio Preferred
13、 Sampling Frequencies for Applications Employing Pulse-Code Modulation AES11-2003, AES Recommended Practice for Digital Audio Engineering Synchronization of Digital Audio Equipment in Studio Operations AES-R2-2004, AES Project Report for Articles on Professional Audio and for Equipment Specifications
