1 2 3 4 5 6 7 8 9 10 Digital Imaging and Communications in Medicine (DICOM) 11 12 Supplement 180: 13 MPEG-4 AVC/H.264 Transfer Syntax 14 15 16 17 18 19 20 21 22 DICOM Standards Committee, Working Group 13 Visible Light 23 1300 N. 17th Street Suite 1752 24 Rosslyn, Virginia 22209 USA 25 26 VERSION: Draft 1.0 Public Comment 27 Developed in accordance with work item 2014-04-A. 28 29 30 Table of Contents 31 Scope and Field of Application ....................................................................................................................... 3 32 Changes to NEMA Standards Publication PS 3.5 .......................................................................................... 4 33 Section 2 Normative references ............................................................................................................... 5 34 8.2.X MPEG-4 AVC/H.264 High Profile / Level 4.2 Video Compression ................................. 6 35 8.2.Y MPEG-4 AVC/H.264 Stereo High Profile / Level 4.2 Video Compression ..................... 7 36 10.X TRANSFER SYNTAX FOR MPEG-4 AVC/H.264 [email protected] IMAGE COMPRESSION 8 37 10.Y TRANSFER SYNTAX FOR MPEG-4 AVC/H.264 STEREO HIGH PROFILE / LEVEL 4.2 38 IMAGE COMPRESSION .......................................................................................................................... 8 39 Annex A (Normative) Transfer Syntax Specifications .................................................................................... 8 40 A.4.X MPEG-4 AVC/H.264 [email protected] VIDEO COMPRESSION ............................................. 8 41 Annex A (Normative) Transfer Syntax Specifications .................................................................................... 9 42 A.4.Y MPEG-4 AVC/H.264 STEREO HIGH PROFILE /LEVEL 4.2 VIDEO COMPRESSION .......... 9 43 Changes to NEMA Standards Publication PS 3.6 ........................................................................................ 10 44 45 Scope and Field of Application 46 This supplement describes two new Transfer Syntaxes to embed MPEG-4 Advanced Video Coding (AVC) 47 / H.264 High Profile / Level 4.2 ([email protected]) and H.264 Stereo High Profile /Level 4.2 encoded pixel 48 data in DICOM. It does not introduce any new SOP Classes or IODs. 49 Transfer Syntax MPEG-4 AVC/H.264 High Profile / Level 4.2 ([email protected]) will perform consistent with 50 the ITU-T H.264 [email protected]. This will enable the storage of video files with a resolution of 1920x1080 51 at 50Hz/60Hz. 52 53 Transfer Syntax MPEG-4 AVC/H.264 Stereo High Profile /Level 4.2 will perform consistent with the ITU-T 54 H.264 Stereo High Profile at Level 4.2. This will enable the storage of video files where higher 55 compression can be achieved due to inter-view prediction. An example of the use would be in binocular 56 operational microscopy. 57 This proposed supplement includes Addenda to existing Parts of DICOM: 58 - PS 3.5 Addendum: Data Structures and Encoding 59 - PS 3.6 Addendum: Data Dictionary 60 In the years since the DICOM Committee WG13 approved the new MPEG-4 AVC/H.264 Transfer Syntax 61 with supplement 149, the capabilities of video recorders and video players have advanced considerably. 62 Support is required in DICOM for 1080P 50/60 Hz as defined by MPEG-4 AVC / H.264 Level 4.2. 63 Considerable space savings can be achieved when storing stereo recordings in Stereo High Profile format. 64 These two new transfer syntax will help to support advance technologies with an updated set of higher 65 resolution, frame rates and compression capabilities. 66 67 68 69 70 71 72 73 74 Changes to NEMA Standards Publication PS 3.5 75 Digital Imaging and Communications in Medicine (DICOM) 76 Part 5: Data Structures and Encoding 77 78 Add references to section 2: 79 Section 2 Normative references 80 … 81 ISO/IS 14495-1 Lossless and near-lossless coding of continuous tone still images (JPEG-LS) 82 ISO/IEC 14496-10:2012 Information technology – Coding of audio-visual objects – Part 10: 83 Advanced Video Coding 84 ISO/IEC 15444-1 JPEG 2000 Image Coding System 85 … 86 87 Add MPEG-4 AVC/H.264 High Profile / Level 4.2 video compression to Section 8. 88 8.2.X MPEG-4 AVC/H.264 High Profile / Level 4.2 Video Compression 89 DICOM provides a mechanism for supporting the use of MPEG-4 AVC/H.264 Image Compression through 90 the Encapsulated Format (see PS 3.3). Annex A defines a Transfer Syntax that references the MPEG-4 91 AVC/H.264 Standard. 92 Note: MPEG-4 AVC/H.264 compression @ High Profile compression is inherently lossy. The context where the 93 usage of lossy compression of medical images is clinically acceptable is beyond the scope of the DICOM 94 Standard. The policies associated with the selection of appropriate compression parameters (e.g. 95 compression ratio) for MPEG-4 AVC/H.264 [email protected] are also beyond the scope of this standard. 96 97 The use of the DICOM Encapsulated Format to support MPEG-4 AVC/H.264 compressed pixel data 98 requires that the Data Elements which are related to the Pixel Data encoding (e.g. Photometric 99 Interpretation, Samples per Pixel, Planar Configuration, Bits Allocated, Bits Stored, High Bit, Pixel 100 Representation, Rows, Columns, etc.) shall contain values that are consistent with the characteristics of 101 the compressed data stream, with some specific exceptions noted here. The Pixel Data characteristics 102 included in the MPEG-4 AVC/H.264 bit stream shall be used to decode the compressed data stream. 103 Notes: 1. These requirements are specified in terms of consistency with what is encapsulated, rather than in 104 terms of the uncompressed pixel data from which the compressed data stream may have been derived. 105 2. When decompressing, should the characteristics explicitly specified in the compressed data stream be 106 inconsistent with those specified in the DICOM Data Elements, those explicitly specified in the 107 compressed data stream should be used to control the decompression. The DICOM data elements, if 108 inconsistent, can be regarded as suggestions as to the form in which an uncompressed data set might 109 be encoded. 110 111 The requirements are: 112 Planar Configuration (0028,0006) shall be 0 113 Samples per Pixel (0028,0002) shall be 3 114 Photometric Interpretation (0028,0004) shall be YBR_PARTIAL_420 115 Bits Allocated (0028,0100) shall be 8 116 Bits Stored (0028,0101) shall be 8 117 High Bit (0028,0102) shall be 7 118 Pixel Representation (0028,0103) shall be 0 119 The value of MPEG-4 AVC/H.264 sample aspect_ratio_idc shall be 1 in the encapsulated MPEG-4 120 AVC/H.264 bit stream if aspect_ratio_info_present_flag is 1. 121 Pixel Aspect Ratio (0028,0034) shall be absent. This corresponds to a 'Sampling Aspect Ratio' (SAR) 122 of 1:1. 123 The possible values for Rows (0028,0010), Columns (0028,0011), Cine Rate (0018,0040) , and Frame 124 Time (0018,1063) or Frame Time Vector (0018,1065) depend on the used transfer syntax. 125 o For MPEG-4 AVC/H.264 High Profile / Level 4.2 transfer syntax, the values for these data 126 elements shall be compliant with the High Profile / Level 4.2 of the MPEG-4 AVC/H.264 127 standard (ISO/IEC 14496-10:2012) and restricted to a square pixel aspect ratio. 128 129 130 Notes: 1. The value of Planar Configuration (0028,0006) is irrelevant since the manner of encoding components 131 is specified in the MPEG-4 AVC/H.264 standard, hence it is set to 0. 132 2. The frame rate of the acquiring camera for ’30 Hz HD’ MPEG-4 AVC/H.264 may be either 30 or 133 30/1.001 (approximately 29.97) frames/sec. Similarly, the frame rate in the case of 60 Hz may be either 134 60 or 60/1.001 (approximately 59.94) frames/sec. This may lead to small inconsistencies between the 135 video timebase and real time. The relationship between frame rate and frame time is shown in Table 8-x. 136 3. The Frame Time (0018,1063) may be calculated from the frame rate of the acquiring camera. A frame 137 rate of 29.97 frames per second corresponds to a frame time of 33.367 ms. 138 4. The value of chroma_format for this profile and level is defined by MPEG as 4:2:0. 139 5. SEI (Supplemental Enhancement Information) elements called frame packing arrangement are used 140 to indicate stereo formats within the video data. 141 142 Table 8-x 143 MPEG-4 AVC/H.264 High Profile / Level 4.2 IMAGE TRANSFER SYNTAX FRAME RATE ATTRIBUTES Video Type Frame Rate Frame Time (see Note 2) (see Note 3) 30 Hz HD 30 33.33 ms 25 Hz HD 25 40.0 ms 60 Hz HD 60 16.17 ms 50 Hz HD 50 20.00 ms 144 145 One fragment shall contain the whole MPEG-4 AVC/H.264 bit stream. 146 Note: If a video stream exceeds the maximum length of one fragment (approximately 4 GB), it may be sent as 147 multiple SOP Instances, but each SOP Instance will contain an independent and playable bit stream, and 148 not depend on the encoded bit stream in other (previous) instances. The manner in which such separate 149 instances are related is not specified in the standard, but mechanisms such as grouping into the same 150 Series, and references to earlier instances using Referenced Image Sequence may be used. 151 152 The container format for the video bitstream shall be MPEG-2 Transport Stream, a.k.a. MPEG-TS (see 153 [ISO/IEC 13818-1]) or ISO base media file format / MP4 (see [ISO/IEC 14496-12] and [ISO/IEC 14496- 154 14]). The supported audio formats are those listed in Table 8-6: Allowed audio formats as defined for 155 MPEG-4 AVC/H.264 High Profile Level 4.1.