SMPTE OV 2073-0-2016 VC-5 Video Essence - Overview for the SMPTE 2073 Document Suite.pdf

1、 Approved April 27, 2016 Copyright 2016 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 SMPTE OV 2073-0:2016 SMPTE OVERVIEW VC-5 Video Essence Overview for the SMPTE 2073 Document Suite Page 1 of 4 pages Table of Contents 1 Introductio

2、n . 2 2 Scope 4 2.1 Scope SMPTE ST 2073-1:2014 Elementary Bitstream 4 2.2 Scope SMPTE RP 2073-2:2014 Conformance Specification . 4 2.3 Scope SMPTE ST 2073-3:2015 Image Formats . 4 2.4 Scope SMPTE ST 2073-4:2015 Subsampled Color Difference Components 4 Foreword SMPTE (the Society of Motion Picture an

3、d Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineer

4、ing Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accor

5、dance with the rules given in its Standards Operations Manual. SMPTE OV 2073-0 was prepared by Technology Committee 10E. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Engineering Document. However,

6、 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 responsible for identifying any or all such patent rights. SMPTE OV 2073-0:2016 Page 2 of 4 pages 1 Introduction The SMPTE 2073 document suite defines the sy

7、ntax and semantics of the VC-5 bitstream. The VC-5 codec is a variable-bit-rate codec intended for high-quality video acquisition and post-production, capable of encoding diverse image and video formats. The key design goals of the VC-5 codec are: (1) very high visual quality (visually lossless in m

8、ost applications); (2) efficient implementation of both decoders and encoders; (3) support for any color space or color difference component sampling; (4) direct encoding of camera sensor output without conversion to a different format; and (5) adaptability and ease of use in video editing and post-

9、production. Before encoding, an image unpacking process converts an image into an ordered set of component arrays that are represented in the VC-5 bitstream. A component array is like an image plane and typically would contain a single type of color or data with up to 24 bits per component and up to

10、 thousands of components. The image unpacking process is not specified in the SMPTE ST 2073 document suite. The VC-5 codec is not restricted to a particular set of image dimensions, pixel formats, or color standards. Common image formats, including images with RGB and YCbCr color components with an

11、optional alpha channel and subsampled color difference components, for example YCbCr with 4:2:2 or 4:2:0 sampling, can be represented in a VC-5 bitstream. Color Filter Array (CFA) images, including Bayer pattern images, and non-color data, such as disparity values, can be unpacked into component arr

12、ays and encoded into a VC-5 bitstream. The encoded bitstream represents the ordered set of component arrays such that a decoding process can reconstruct the set of component arrays, except for losses due to compression, in the same order as input to the encoding process. The decoding process can be

13、followed by an image repacking process that converts the ordered set of component arrays into a packed representation of the image. The image repacking process is not specified in the SMPTE 2073 document suite. The dependencies between documents in the VC-5 suite are illustrated in Figure 1. The arr

14、ows indicate that a lower numbered part should be read before a higher numbered part. SMPTE OV 2073-0:2016 Page 3 of 4 pages VC -5 Pa rt 1El e me nta ry Bi tst re amVC -5 Pa rt 2Conforma n ce Sp e ci fi ca ti onVC -5 Pa rt 3Ima g e F o rma tsVC -5 Pa rt 4C o lo r Su b sa mp lingFigure 1 Dependencies

15、 between documents in the VC-5 document suite SMPTE OV 2073-0:2016 Page 4 of 4 pages 2 Scope This informative overview describes the documents in the SMPTE 2073 suite. 2.1 Scope SMPTE ST 2073-1:2014 Elementary Bitstream SMPTE ST 2073-1 defines the compressed representation and decoding process for t

16、he VC-5 elementary bitstream. Any image or array of data that can be unpacked into component arrays can be represented by a VC-5 elementary bitstream. 2.2 Scope SMPTE RP 2073-2:2014 Conformance Specification SMPTE RP 2073-2 specifies the criteria and procedures for testing the conformance of encoder

17、 and decoder implementations to the VC-5 standard and describes the test materials used for conformance testing. The test materials used for conformance testing comprise a reference decoder for testing bitstreams created by implementations of a VC-5 encoder for compliance with the VC-5 standard and

18、reference bitstreams for testing implementations of a VC-5 decoder for compliance with the VC-5 standard. 2.3 Scope SMPTE ST 2073-3:2015 Image Formats The VC-5 elementary bitstream defined in SMPTE ST 2073-1 does not specify the type of components that are represented in the bitstream. SMPTE ST 2073

19、-3 extends the elementary bitstream syntax with new elements for representing RGB(A) images, YC1C2(A) images without color difference component sub-sampling, and Color Filter Array (CFA) images including Bayer image formats. 2.4 Scope SMPTE ST 2073-4:2015 Subsampled Color Difference Components SMPTE

20、 ST 2073-4 extends the YC1C2(A) image format defined in SMPTE ST 2073-3 to include subsampled color difference components, including 4:2:2, 4:2:0, 4:1:1, and 4:1:0 subsampling. An alpha channel is optional and can have the same resolution as the Y channel or the same resolution as the C1 and C2 channels.