1、 The attached SMPTE Engineering Document has been declared “Stable” by the controlling Technology Committee. The SMPTE Operations Manual for Standards states: A document should be stabilized if it is believed to be substantially correct, does not contain harmful or misleading recommendations, may st
2、ill be relevant to equipment or practices in use, is stable, but does not represent current technology, and need not be subject to future reviews. A Stable document shall still be made available and offered for sale by the Society, but it shall be prefaced by a cover page explaining its current stat
3、us. At any time, a Technology Committee may revise, amend, or otherwise initiate a new Project on a Stable document. A Stable document is “In Force”, and not deprecated or withdrawn. * * * * * * * * * * Note: SMPTE “Stable” documents were previously described as “Archived” and the attached document
4、may be marked as “Archived”. The status of a SMPTE document described as “Archived” is exactly as described above for a “Stable” document. Stable documents may not adhere to the latest style and format of SMPTE documents, or to current usage of normative language. Suitable care should be taken in in
5、terpretation. SMPTE STABLE DOCUMENT Page 23 of 26 pages Table of Contents Page Foreword 2 Intellectual Property 2 1 Scope 3 2 Normative References 3 3 Definitions 4 4 File . 8 5 Generic Headers . 10 5.1 File Information Header . 10 5.2 Image Information Header 11 5.3 Image Source Information Header
6、11 6 Industry-Specific Headers . 12 6.1 Motion-Picture Film Information Header . 12 6.2 Television Information Header 12 7 User Defined Data . 13 8 Image Data 13 9 Application Specific Header Value Constraints . 18 9.1 General 18 9.2 Academy Density Exchange Encoding (ADX) 18 Annex A Structure of SM
7、PTE ST 268 File and Representation in Documents (Informative) . 20 Annex B Byte-Order Conventions (Informative) 21 Annex C Data-Packing Diagrams (Figures C.1 through C.8) (Informative) 22 Annex D Relationship of Metadata Items to SMPTE Metadata Dictionary SMPTE RP 210 (Informative) . 25 Annex E Bibl
8、iography (Informative) . 26 Page 1 of 26 pages SMPTE ST 268:2014 Revision of SMPTE 268M-2003 Copyright 2014 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 SMPTE STANDARD File Format for Digital Moving- Picture Exchange (DPX) Approved
9、November 1, 2014 Correction to Table 5B made on January 15, 2015 SMPTE ST 268:2014 Page 2 of 26 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of Ame
10、rica, 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 their work
11、. 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 its Standards Operations Manual. SMPTE ST 268 was prepared by Technology Committee 31FS. Intellectual Property At the ti
12、me of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Engineering Document. However, attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. SMPTE shall not be held responsib
13、le for identifying any or all such patent rights. SMPTE ST 268:2014 Page 3 of 26 pages 1 Scope 1.1 This standard defines a file format for the exchange of digital moving pictures on a variety of media between computer-based systems. It does not define the characteristics of input or output devices o
14、r displays. This format will be known as the SMPTE digital picture exchange format version 2.0, or DPX in short form. The file extension will be .dpx. 1.2 This flexible, resolution-independent file format describes pixel-based (raster) images with attributes defined in the binary file header. Each f
15、ile represents a single image with up to eight image elements. Image elements are defined as a single component (e.g. luma) or multiple components (e.g. red, green, and blue) as defined by Table 1. 1.3 Image data is packed for efficient storage with the option to pad to 32-bit word boundaries (two a
16、lternative padding formats are allowed: see table 3B and annex B). Multibyte quantities may be stored with either the most significant byte first or the least significant byte first, where first means in the location with the lowest address, or the first byte in sequence from a byte-serial data chan
17、nel. Both byte-order conventions are supported. The magic number in field 1 of the file information section is used to distinguish the byte order (annex A provides an historical perspective for the existence of the two byte-order conventions). 2 Normative References Note: All references in this docu
18、ment to other SMPTE documents use the current numbering style (e.g. SMPTE ST 240:1999) although, during a transitional phase, the document as published (printed or PDF) may bear an older designation (such as SMPTE 240M-1999). Documents with the same root number (e.g. 240) and publication year (e.g.
19、1999) are functionally identical. The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this st
20、andard are encouraged to investigate the possibility of applying the most recent edition of the standards indicated below. ANSI/IEEE 754-1985 (R1991), Binary Floating-Point Arithmetic SMPTE ST 12-1:2014, Time and Control Code SMPTE ST 125:2013, SDTV Component Video Signal Coding 4:4:4 and 4:2:2 for
21、13.5 MHz and 18 MHz Systems SMPTE ST 240:1999, Television 1125-Line High-Definition Production Systems Signal Parameters SMPTE ST 254:2008, Motion-Picture Film (35-mm) Manufacturer-Printed, Latent Image Identification Information SMPTE ST 274:2008, Television 1920 x 1080 Image Sample Structure, Digi
22、tal Representation and Digital Timing Reference Sequences for Multiple Picture Rates SMPTE ST 296:2012, 1280x720 Progressive Image 4:2:2 and 4:4:4 Sample Structure Analog and Digital Representation and Analog Interface SMPTE ST 2065-3:2012, Academy Density Exchange Encoding (ADX) Encoding Academy Pr
23、inting Density (APD) Values ISO 8601:2004, Data Elements and Interchange Formats Information Interchange Representation of Time and Dates ISO/IEC 8859-1:1998, Information Processing 8-Bit Single-Byte Coded Graphics Character Sets Latin Alphabets 1 SMPTE ST 268:2014 Page 4 of 26 pages ITU-R BT.601-5
24、(10/95), Studio Encoding Parameters of Digital Television for Standard 4:3 and Wide-Screen 16:9 Aspect Ratios ITU-R BT.709-5 (04/02), Parameter Values for the HDTV Standards for Production and International Programme Exchange 3 Definitions The reference field number from Sections 5 and 6 is indicate
25、d in brackets at the end of each definition: 3.1 magic number Indicates the start of the image file and is used to determine byte order. The file format allows machines to create files in either of the two most common byte orders, whichever is easier for that machine. Byte-order translation is only
26、required for machines reading files that were created on a machine with reverse byte order. Programs creating DPX files should write the magic number with the ASCII value of SDPX (0x53445058 hex). Programs reading DPX files should use the first four bytes to determine the byte order of the file. The
27、 first four bytes will be S, D, P, X if the byte order is most significant byte first, or X, P, D, S if the byte order is least significant byte first. 1 3.2 image file size Indicates the size of the entire file; i.e. containing both header and image data. 4 3.3 ditto key Indicates that all fields a
28、re the same as the previous frame in the sequence except for fields related to the frame number (48, 50, 58, 61). Also, the offsets to the image data (21.12) will change if run-length encoding is used. The ditto key is a read-time shortcut only, and the other fields in the header must still be fille
29、d in when the file is created. 5 3.4 creation date/time Defined as yyyy:mm:dd:hh:mm:ssLTZ, formatted according to ISO 8601. 10 “LTZ” means “Local Time Zone;” format is: LTZ = Z (time zone = UTC), or LTZ = +/hh, or LTZ = +/hhmm (local time is offset from UTC) 3.5 encryption key Indicates that the ima
30、ge data is encrypted to prevent unauthorized use. The default is FFFFFFFF for no encryption. Any other value indicates that the image data is encrypted and this value can be used as the encryption key. Note that the header data is not encrypted. 15 3.6 image orientation Indicates the orientation of
31、the image data required for display. The possible orientations are listed in Table 2. The standard orientation for core set images (code 0) is left to right (line direction) and top to bottom (frame direction). 17 3.7 image element data structure A data structure (group of fields) is repeated for ea
32、ch image element. An image element can contain a single component or multiple components, as defined in Table 1. The presentation order of both whole elements SMPTE ST 268:2014 Page 5 of 26 pages and components of multi-component image elements is also defined in Table 1. All components in an image
33、element must have the same number of bits, transfer function, and colorimetric specification. 21 3.8 reference low data code value Defines the minimum expected code value for image data. For printing density, the default value is 0. For ITU-R 601-5 luma, the default value is 16. 21.2 3.9 reference l
34、ow quantity represented Defines the corresponding signal level or measured value to the reference low data code value. For printing density, the default is a density of 0.00. For ITU-R 601-5, the luma default is 0 mV. 21.3 3.10 reference high data code value Defines the maximum expected code value f
35、or image data. For 10-bit printing density, the default code value is 1023. For ITU-R 601-5 luma, the default value is 235. 21.4 3.11 reference high quantity represented Defines the corresponding signal level or measured value to the reference high data code value. For printing density, the default
36、is a density of 2.048. For ITU-R 601-5 luma, the default is 700 mV. 21.5 3.12 descriptor for image element n Defines the components that make up an image element and their pixel packing order. The valid components are listed in Table 1. 21.6 3.13 transfer characteristic Defines the amplitude transfe
37、r function used to transform the data from a linear original. The inverse of the transfer function is needed to recreate a linear image element (see Table 5A). 21.7 3.14 colorimetric specification Defines the appropriate color reference primaries (for additive color systems like television) or color
38、 responses (for printing density) (see Table 5B). 21.8 3.15 bit depth Defines the number of bits for each component in the image element. All components must have the same bit depth. Valid bit depths are 1-, 8-, 10-, 12-, and 16-bit integer, and 32- and 64-bit IEEE floating point (see Table 3A). 21.
39、9 3.16 packing For image element n, defines the data packing mode. The valid options are listed in Table 3B. 21.10 3.17 encoding For image element n, defines whether or not the element is run-length encoded. The valid options are listed in Table 3C. 21.11 3.18 offset To data for image element n, def
40、ines the offset in bytes to the image data for element n from the beginning of the file. 21.12 SMPTE ST 268:2014 Page 6 of 26 pages 3.19 end-of-line padding Specifies the number of padded bytes at the end of each line. The default is 0 (no padding). 21.13 3.20 end-of-image padding Specifies the numb
41、er of padded bytes at the end of each image element. The default is 0 (no padding). 21.14 3.21 X offset Defines the line offset (in pixels) from the first pixel in the original image. The default is 0. This is useful if an image is cropped and the user wishes to specify its location with respect to
42、the original contiguous image.30 3.22 Y offset Defines the frame offset (in lines) from the first line in the original contiguous image. The default is 0. 31 3.23 X center Defines the X image center in pixel units (floating point). 32 3.24 Y center Defines the Y image center in line units (floating
43、point). 33 3.25 X pixel count Defines the number of pixels per line in the original image. 34 3.26 Y pixel count Defines the number of lines per image in the original image. 35 3.27 source image filename Defines the source image from which this image was extracted or processed. 36 3.28 source image
44、date/time Defines the creation time of the source image from which the image was extracted or processed. Formatting is as per Section 3.4 37 3.29 border validity Defines the region of an image that is eroded due to edge-sensitive filtering operations. The X-left, X-right, Y-top, and Y-bottom value d
45、efines the width of the eroded border. The default is 0,0,0,0 in pixel units (no erosion). 40 3.30 pixel aspect ratio Specified as the ratio of a horizontal integer and a vertical integer. For example, a SMPTE ST 274 signal has a pixel aspect ratio of 1:1, which is 1920 active pixels and 1080 active
46、 lines in a 16:9 frame. 41 3.31 X scanned size Defines the horizontal size of the original scanned optical image in millimeters. 42.1 SMPTE ST 268:2014 Page 7 of 26 pages 3.32 Y scanned size Defines the vertical size of the original scanned optical image in millimeters. 42.2 3.33 film edge code info
47、rmation Encodes data from machine readable portion of film edge code, according to SMPTE ST 254. 43, 44, 45, 46, 47, 48 3.34 frame position in sequence Defines the frame number in the image sequence. 50 3.35 sequence length Defines the total number of frames in the image sequence. 51 3.36 held count
48、 Specifies how many sequential frames for which to hold the current frame. In animation, it is often desirable to hold identical frames. 52 3.37 shutter angle Defines the shutter angle in degrees of the motion-picture camera. This specifies the temporal sampling aperture. 54 3.38 frame identificatio
49、n A user-defined field that labels select frames as key frames or wedge frames, etc. 55 3.39 slate information A user-defined ASCII field for recording production information from the camera slates. 56 3.40 SMPTE time code The characters are encoded into the 32-bit word according to Table 6. 58 3.41 SMPTE user bits These are encoded according to Table 6. 59 3.42 field number Of the first field in the file, may be 1 or 2 for component video, 1 t
