This standard specifies certain parameters and technical characteristics of the picture and sound of 35mm and 70mm film post-production materials for international and domestic exchange, and also specifies a quality assessment method based on standard test pictures contained in post-production picture materials. GB/T 20231-2006 Exchange of film post-production materials GB/T20231-2006 standard download decompression password: www.bzxz.net
This standard specifies certain parameters and technical characteristics of the picture and sound of 35mm and 70mm film post-production materials for international and domestic exchange, and also specifies a quality assessment method based on standard test pictures contained in post-production picture materials.

ICS 37.060.20
National Standard of the People's Republic of China
GB/T20231—2006
Interchange of post-production materials
Cinematography-
Interchange of post-production materials(ISO12612:1997MOD)
Issued on April 21, 2006
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implementation on October 1, 2006
This standard modifies ISO12612:1997 "Exchange of post-production materials" (American version). The main differences between this standard and ISO12612:1997 are as follows: GB/T20231-2006
Most of the international standards in Chapter 2 "Normative References" are changed to corresponding national standards or industry standards: A.1 in Appendix A is deleted. A.2 is changed to A.1, A.3 is changed to A.2. Appendix B is changed to references.
Appendix A of this standard is an informative appendix.
This standard is proposed and coordinated by the State Administration of Radio, Film and Television. This standard is drafted by the China Film Science and Technology Research Institute. The main drafter of this standard is Gu Xintai.
1 Scope
Exchange of post-production materials of movies
GB/T202312006
1.1 This standard specifies certain parameters and technical characteristics of the picture and sound of post-production materials of 35mm and 70mm movies for international and domestic exchange.
1.2 This standard also specifies a quality assessment method based on standard test surfaces included in post-production image materials. 2 Normative references
The clauses in the following documents become clauses of this standard through reference in this standard. For any dated referenced document, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For any undated referenced document, the latest version applies to this standard. GB/T2926-2000 Technical specifications for the header and tail of 35mm and 16mm film distribution (eqyISO4241:1987) GB/T4635-2000 Position and size of the image formed by the film window of a 35mm movie camera on the film (eqV1S02906:1984)
GB/T4636-2000
Position and size of the maximum projectable image on a 35mm film (eq1S02907:1984) GB/T4637-1994 Position and width of the gap between the three-track, four-track and six-track magnetic heads on a 35mm magnetic film (eqvISO162:19853
GB/T4645-1994 Screen brightness for indoor cinemas and screening rooms (enVISO2910.1990) GB/T53 00-1994 Dimensions and positions of 70mm, 65mm, 35mm and 16mm film joints (negISO6038:1993)
GB/T6848-1986 Dimensions of film cores for film reels (eqvISO1039:1975) GB/T9048-1988 Position and dimensions of the image formed by the film windows of 65mm and 70mm movie cameras and the maximum projection screen of 70mm film copies (neqIS02467:1980) GB/T11500-1989 Geometric conditions for photographic transmission density measurements (neqISO512:1985) GB/T11501-1989 Optical harmonic conditions for photographic density measurements (neqIS0513:1984) GY/T190-2003 Film for exchange and its aldehyde (sound link) rope Minimum content of material container label HG/T2695-1995 Motion picture film size
ISO4834:1986 Motion picture magnetic sound test film other than magnetic coated release copy basic technical characteristics ISO9525:1988 Motion picture recording head gap position and width dimensions for two-channel recording on 17.5mm magnetic tape 3 Requirements for post-production picture materials
3.1 Cutting and punching dimensions
The cutting and punching dimensions of photographic film should be consistent with the industry standards given in 3.1.1 to 3.1.3. 3.1.1 35mm negatives, positives and negatives: HG/T2695-1995 (N-type perforations and 4.74mm hole spacing are preferred). 3.1.2 35mm projection copies: HG/T2695-1995 (P-type perforations and 4.75mm hole spacing). 3.1.3 65m m negatives, positives and negatives and 70mm projection prints: HG/T2695-1995. 3.2 Position and size of the picture
The position and size of the picture shall be consistent with the national standards given in 3.2.1 and 3.2.2. 3.2.1 35mm GB/T4635--2000 and GB/T4636-2000. 3.2.2 65mm and 70mm GB/T9048-19881
GB/T20231-2006
3.3 Connectors
The provisions for connecting and purchasing in the United States shall be consistent with the current provisions of GB/T5300-1994. 3.4 Requirements for photosensitive properties
The photosensitive properties of the post-production picture materials to be exchanged shall be evaluated by density measurement of the standard test high and high density measured by connecting to the original negative film roll and duplicating it according to the steps. The control method is based on the photofinishing control target density system (LAD system), which assigns a specific density value to the control block portion of the standard frame that is connected to the original photographic film, and then reads it at each stage of the copy production. All images in the film will be matched to the conditions of the standard frame that is considered to be "perfect". The target value of density should be selected so that the equivalent print-through neutral density value of each roll of film falls roughly at the middle point of the straight line portion of the film characteristic curve throughout the post-production process of copy production. This can achieve the following two self-interests:
-most of the image information falls on the linear portion of the characteristic curve of the copy film, maximizing the information of the highlights and shadows;
-a uniform neutral gray gradient can be maintained throughout the post-production color matching. A picture suitable for LAD control should be a picture shot by a camera, which should include a large enough area of ​​neutral gray to facilitate density measurement. This neutral gray area should be placed in a position in the scene that is suitable for subjective evaluation. Under the lighting conditions of the scene, a plate with an 18% time reversal is usually suitable. This LAD control image will be inserted into the original film reel as specified in 3.5.3. Ultimately, the quality of the picture needs to be evaluated subjectively by humans, but as long as the characteristics of common films, printers and processes, and specific film reproduction systems are kept within the permissible tolerance range, the target measurement of the LAD system will help us obtain stable copies with good tonal and color reproduction characteristics.
3.4.1 Density Measurement
Standard The density of all picture materials used for reproduction will be measured by the non-transmission density measurement method specified in GB/T11500-1989 and GB/T11501-1989 in the M state. The density of pictures prepared for skin viewing will be measured by the diffuse radiation density measurement method specified in GB/T11500-1989 and GB/T11501-1989 in the A state. 3.4.2 Density of the original photographic negative on the LAD standard pattern The density of the LA control portion of the LAD control block (see Appendix A) should be selected so that it can represent the center value of the density of a normal, photosensitive color film roll.
3.4.3 Density of the LAD standard pattern on the original negative The control portion of the LAD should be printed at the center of the usable straight line portion of the duplication film, the target density specified by the film manufacturer for that particular duplication film.
3.4.4 Density of the LAD standard pattern on the duplication film The control portion of the LAD should be printed at the target density specified by the manufacturer for that particular duplication film. These densities are usually close to the center point of the usable straight line portion of the characteristic curve and may be different from that of the duplication film to increase interoperability with the original negative film shot by the camera and to facilitate rapid printing.
3.4.5 Density of the LAD standard picture when the control part of the LAD is printed on the copy, it should be 1.00 middle gray density (1.00 equivalent neutral density), the A state density corresponding to 1.00 middle gray is specified by the film manufacturer, and it is also determined according to the dye in the copy film and the viewing brightness specified in GB/T4645-1994:
3.5 Trailer of picture material
3.5.1 The head and tail trailers of the picture should be consistent with the provisions of GB/T2926-2000. 3.5.2 A sync mark clearly marked with "head sync" should be placed on the "gate" frame (frame 192) of the head traction film. The mark mentioned in 3.5.33.4 should be placed somewhere in or in front of the head traction film and ensure that the printer speed has reached full speed and stabilized when it is finished. It is recommended to replace 1 to 6 frames from frames 97 to 102 in the head traction film with test pictures. 2
3.5.4 Additional requirements for head and tail traction films will be determined based on the cooperation of the production parties. 4 Requirements for post-production sound materials
4.1 Cutting and perforation size
GB/T20231-2006
The cutting and perforation size of 35mm movie disks should be consistent with HG/ T26951995 (P-type perforations and 4.75mm hole spacing
Note: 17.5mm magnetic tape is only allowed with the prior agreement of both parties. 4.2 Position, size and allocation of sound tracks
The position, size and allocation of sound tracks shall be consistent with the provisions of GB/T4637-1994 for 35mm magnetic tape and ISO9525:1988 for 17.5mm magnetic tape. 4.3 Nominal rate
The nominal rate of recording of 35mm magnetic soundtracks shall be the same as the projection rate of the corresponding pictures, usually 24 frames per second, that is, 96 sprocket holes per second or about 456mm/s
4.4 Recording
The recorded material shall be made on magnetic tape without joints. , no more than two splices are permitted on any one disc. 4.5 Recordings of sound for exchange to make a mono release copy The recordings of sound shall be made using the following standards: - single-track sound on separate discs; - three- or four-track sound on a single disc. 4.5.1 The recording of three tracks of sound on a single disc shall follow the following track allocation: a) 1 track - dialogue:
b) 2 tracks - music:
c) 3 tracks - sound effects.
4.5.2 The recording of four tracks of sound on a single disc shall follow the following track allocation: a) 1 track
b) 2 tracks
e) 3 tracks
Dialogue:
Music:
Number of sound effects:
Special sound components (see Note)
Note! Special sound components may include original or reference dialogue, or may be live sound that is consistent with the original dialogue and needs to be used separately in the later stage, such as group or live music, laughter or special sound effects, etc. (see A.2 in Appendix A) 4.6 Exchange of recorded sound for the purpose of making a stereo release copy shall be carried out in a three-track or four-track matrix coded format or in a separate channel format in the track allocation method specified in 4.6.1 or 4.6.2.
4.6.1 Stereo Matrix Coded Components
a) Track 1 - Special sound components (see Note 1) b) Track 2 Left Coded Component Music and Effects! e) Track 3 - Right Coded Component Music and Effects. It is customary to provide the original dialogue channel (the original dialogue channel is usually provided as a separate monophonic disc) for use by the interpreter and lip sync, which can be provided as a monophonic magnetic or optical soundtrack on the standard print. Suggestion 1: Special sound effects include original dialogue or reference dialogue, which may also be consistent with the dialogue at the same time, live noise that needs to be used separately in the later stage, live music with a chorus, beautiful voice or special sound effects, etc. Note 2: Internationally, some countries also dare to adopt the following track allocation: 3
GB/T20231-2006
a) 1 track
b32 tracks
e) 3 tracks
Music and dynamic effects of left coded components:
Music and dynamic effects of end coded components:
Special sound components (see Note 1)),
4.6.2 Track allocation for stereo sound
a) 1 track
b) 2 tracks
d) 4 tracks
Music and dynamic effects of left channel
Music and dynamic effects of center channel:
Music and dynamic effects of right channel:
Surround music and dynamic effects.
Sound exchange can also be carried out in the format of six tracks given below! a1
d)4 track
e)5 track
D6 track one
Music and animation for left channel!
Music and animation for center channel:
Music and animation for right channel:
Surround music and animation:
Special sound components:
Special sound components.
For the original sound source containing two-way surround sound, the distribution of sound tracks shall be determined by negotiation between the parties concerned. It is customary to provide the original dialogue channel for translation and lip syncing as a reference. It can be provided as a mono magnetic link or optical soundtrack on a standard copy.
4.7 Recordings of sound for exchange to make 70mm release prints Recordings of sound will be exchanged in a six-track format with the following track allocation:a) 1 track
b) 2 tracks
e) 3 tracks
1 Left channel music and effects:
Left center channel music and effects:
Center channel music and effects:
Right center channel music and effects!
Right channel music and effects:
Encircled music and effects.
The original dialogue channel is usually provided on a separate mono disk for reference. Track allocation may be made in other ways, but it must be clearly marked. 4.8 Requirements for sound recording characteristics
The peak level of the individual sound channels should be controlled so that the sum of the individual sound levels does not exceed the tolerance of the sound format of the print to be shown in the cinema.
4.8.1 Frequency range and should: as specified in ISO4834:1986. 4.8.2 Recording level The sound of each sound track should be recorded at the standard level specified in ISO4834:1986. 4.8.3 The relationship between the sound levels of each channel during mixing should be based on ensuring the clarity of the dialogue. 4.8.4 When recording, all situations that damage the sound quality should be avoided. Obvious frequency range and response limitations, non-linear distortion, sound color fluctuations and external noise should be avoided during the recording process. 4.8.5 The sound crosstalk on the multi-track magnetic disc should be reduced to less than 40dB between 100Hz and 10kHz. 4.8.6 A complete set of magnetic sound track materials should include a special test film, which contains the following signals and is recorded on all sound tracks in a synchronous non-noise-reduced manner!
At least 30s of pink noise 10dB below the standard level: - At least 30s of standard level for noise reduction system adjustment: Other additional signals agreed upon by the production parties. Note: The test piece is connected to the front of an aldehyde sound material. 4.9 Trailer of sound material
GB/T20231—2006
4.9.1 The beginning of each disk should have an unrecorded protective trailer of at least 8m in length. The end of the disk should have a protective trailer of at least 5m in length.
4.9.2 After the protective trailer of all disks, a 1000Hz standard level sine wave signal of at least 30 seconds in length should be recorded synchronously on each track.
4.9.3 After the 1000Hz standard level signal, a standard level pink noise signal of at least 30 seconds should be recorded synchronously on all sound tracks of each disk material. Www.bzxZ.net
4.9.4 Other signals (such as calibration signals for noise reduction systems, etc.) can also be included in the head trailer. 4.9.5 Except for the following cases, no test signal should be recorded at the position of the magnetic film corresponding to the picture traction film specified in GB/T2926-2000.
4.9.6 Each magnetic film material should have a sync mark clearly marked with "head sync" (see 3.5.2) at the position synchronized with the frame marked with 2\ (frame 48) in the picture traction film (as specified in GB/T2926-2000). 4.9.7 Each magnetic film material should record a standard level of 1000Hz at a position synchronized with the frame marked with 2\ (frame 48) in the picture traction film (as specified in GB/T2926-2000). 4.9.8 Each disc material should record a 1000H2 sine wave signal of standard level at a position synchronized with the end frame (48th frame) of the picture tail trailer (as specified in GB/T2926-2000). 4.9.9 The trailer should contain at least 30 frames of the beginning of the next sound track. 5 Packaging and Labeling
5.1 The picture film and sound film should be wound on the film reel specified in GB/T6848-1986. 5.2 The film boxes used for transporting or storing post-production materials shall be labeled with various information in accordance with the provisions of GY/T190-2003. For sound magnetic discs, the following information is required to be indicated on the label: Film name:
Book number:
Name of sound track:
Format of one sound track (track 1, track 3, track 4, track 6): For the allocation of sound tracks, see 4.5.4.6 and 4.7): Total length of the entire book including the head and tail traction sheets and protection sheets: Type of sound noise reduction system:
The test signal contained in the traction sheet between the protection sheet and the synchronization section. un
GB/T20231-2006
Appendix A
(Informative Appendix)
Additional information
A, 1 Specified density of LAD test sheets for post-production picture materials The specified density of LAD test sheets for post-production materials of various types and manufacturers is shown in Table A.1. Table A1 LAD Density
M Status Red
M Status Hall
M Status Blue
Screening Print
A.2 Notes on Language in Soundtrack
Kodak Film
0.80±0.02
1.60±0.02
As Specified by Manufacturer
Films with Other Mask Levels
(Density above Fog and Mask)
0.60±0.02
0.60±0.02
Heart60±0.02
Pay special attention to the language in the soundtrack, because not all language-related information appears in the Dialogue track. For example, in a crowd scene, the crowd noise may contain dialogue from the original film, but in post-production, these words are often treated as "crowd noise" and placed in the sound effect recording.
Putting all language-related information in the dialogue track will simplify the language replacement work, but it will increase the difficulty of dubbing because there will be a lot of new content to re-dub. There are no shortcuts here, and all problems must be solved step by step. [Gong
ISO70.1982
1SO543:1990
ISO1189:1986
ISO 2404:1986
ISO 2939.1986
1SO 3640:1982
ISO4246:1994
ISO 7343:1993
ISO8567.1986
ISO 8590:1994
ISO 8687.1987
［12]
References
GB/T20231—2006
Specification for 35 mm optical sound base position and maximum width dimensions for photographic safety films recorded on 35 mm motion picture film
ISO12611:2004
Specification for recording characteristics of magnetic sound recordings other than magnetic coated release prints
6-track magnetic sound recording positions and dimensions on 70 mm formaldehyde coated release prints for 35 mm motion picture release prints Image area and location and dimensions of optical recordings Vocabulary of specifications for film prints and recordings for international exchange of television programmes
Location and width dimensions of two-track optical recordings on 35 mm film prints Maximum area dimensions and locations of subtitles permitted on 35 mm and 16 mm film release copies Recording characteristics of magnetically coated 35 mm or 70 mm film release copies Methods of measuring the signal-to-noise ratio of variable-area optical recordings over 8 mm, 16 mm and 35 mm Film
Specifications and locations of test signals for the pull-through section of 35 mm magnetic substrates for international exchange
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