1、SMPTE RECOMMENDED PRACTICE RP 79-1 999 Revision of RP 79-1994 SDecifications for Flutter Test Film for 35-mm Four-Track Striped Release Print Audio Reproducers, Magnetic Type 1 Scope This practice specifies a test film for determining the presence of flutter in 35-mm motion-picture mag- netic audio
2、reproducers operating at 96 perforations per second or approximately 90 ft (27 m) per minute designed for four-track magnetic audio release prints. Page 1 of 2 pages 3 Test film signal 3.1 Frequency The audio record shall be an original recording which will reproduce at a frequency of 31 50 Hz f 25
3、Hz when the linear speed of the film is 96 perforations per second or approximately 90 ft (27 m) per minute (18 in or 46 cm per second). 2 Normative references 3.2 Distortion The following standards contain provisions which, through reference in this text, constitute provisions of this practice. At
4、the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this practice are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. ANSI S4.3-1982 (R1992), Method for M
5、easurement of Weighted Peak Flutter of Sound Recording and Reproducing Equipment ANSI S4.6-1982 (R1992), Method of Measuring Recorded Flux of Magnetic Sound Records at Medium Wavelengths ANSVSMPTE 102-1 997, Motion-Picture Film (35- mm) - Perforated CS-1 870 ANWSMPTE 137-1 994, Motion-Picture Film (
6、35- mm) - Release Prints - Four Magnetic Audio Records ANSVSMPTE 177-1 995, Motion-Picture Film (35- mm) - Four-Track Magnetic Audio Release Prints - Magnetic Striping ANSI/SMPTE 223M-1996, Motion-Picture Film - Safety Film The total harmonic distortion of the recorded signal shall not exceed 0.2%.
7、3.3 Audio record 3.3.1 Full-coat The audio record on full-coat material shall be re- corded so that it extends from one edge of the film to the other. 3.3.2 Striped release print For release prints that are striped in accordance with ANSI/SMPTE 177, the audio record shall be recorded in accordance w
8、ith ANSVSMPTE 137. 3.4 Recorded level The flutter test tone shall be not less than 6 dB down from the equivalent reference level of 1 kHz at 185 nanowebers per meter after correct equalization of 35 ps and 31 80 ps. 3.5 Flutter The weighted peak flutter of the audio record shall not exceed tr 0.04% when measured in accordance with ANSI S4.3. Copyright O 1999 by the SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved April 22, 1999
