1、 CEA Standard DTV Remodulator Specification with Enhanced OSD Capability CEA-761-B R-2012 May 2007 NOTICE Consumer Electronics Association (CEA) Standards, Bulletins and other technical publications are designed to serve the public interest through eliminating misunderstandings between manufacturers
2、 and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards, Bulletins and other technical publications shall not in any respect preclud
3、e any member or nonmember of CEA from manufacturing or selling products not conforming to such Standards, Bulletins or other technical publications, nor shall the existence of such Standards, Bulletins and other technical publications preclude their voluntary use by those other than CEA members, whe
4、ther the standard is to be used either domestically or internationally. Standards, Bulletins and other technical publications are adopted by CEA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, CEA does not assume any liability to any patent owner, n
5、or does it assume any obligation whatever to parties adopting the Standard, Bulletin or other technical publication. This document does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the responsibility of the user of this document
6、to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. This document is copyrighted by the Consumer Electronics Association (CEA) and may not be reproduced, in whole or part, without written permission. Federal copyright law
7、prohibits unauthorized reproduction of this document by any means. Organizations may obtain permission to reproduce a limited number of copies by entering into a license agreement. Requests to reproduce text, data, charts, figures or other material should be made to CEA. (Formulated under the cogniz
8、ance of the CEA R4.8 DTV Interface Subcommittee.) Published by CONSUMER ELECTRONICS ASSOCIATION 2012 Technology Phone 800-542-5040; Fax 610-363-5898; Internet http:/www.scte.org; Email infoscte.org ; OR Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112-
9、5776; Phone 800-854-7179; Fax 303-397-2740; Internet http:/; Email 1CEA-761-B CEA Standards: Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112-5776; Phone 800-854-7179; Fax 303-397-2740; Internet http:/; Email ATSC Standards: Advanced Television Syste
10、ms Committee (ATSC), 1750 K Street N.W., Suite 1200, Washington, DC 20006; Phone 202-872-9160; Fax 202-872-9161; Internet http:/www.atsc.org IEC Standards: Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112-5776; Phone 800-854-7179; Fax 303-397-2740; Int
11、ernet http:/; Email IEC Central Office, 3, rue de Varembe, PO Box 131, CH-1211 Geneva 20, Switzerland; Phone +41 22 919 02 11; Fax +41 22 919 03 00; Internet http:/www.iec.ch; Email pubinforiec.ch 2.2 Informative References 2.2.1 Informative References List CEA-CEB5-B, Recommended Practice for DTV
12、Receiver “Monitor” Mode Capability, May, 2007 ISO/IEC 13818-1 (2000), Information Technology - Generic coding of moving pictures and associated audio information: Systems 2.2.2 Informative References Acquisition CEA Bulletins: Global Engineering Documents, World Headquarters, 15 Inverness Way East,
13、Englewood, CO USA 80112-5776; Phone 800-854-7179; Fax 303-397-2740; Internet http:/; Email ISO/IEC Standards: Global Engineering Documents, World Headquarters, 15 Inverness Way East, Englewood, CO USA 80112-5776; Phone 800-854-7179; Fax 303-397-2740; Internet http:/; Email IEC Central Office, 3, r
14、ue de Varembe, PO Box 131, CH-1211 Geneva 20, Switzerland; Phone +41 22 919 02 11; Fax +41 22 919 03 00; Internet http:/www.iec.ch; Email pubinforiec.ch ISO Central Secretariat, 1, rue de Varembe, Case postale 56, CH-1211 Geneve 20, Switzerland; Phone + 41 22 749 01 11; Fax + 41 22 733 34 30; Intern
15、et http:/www.iso.ch ; Email centraliso.ch 3 DTV Remodulator RF Output Specifications The entire transport modulation system shall be compliant with ATSC A/53E Annex D Section 5 and Section 6. 3.1 Selectable Output Channel Frequency The remodulators channel frequency tolerance shall be 10 kHz. For ve
16、stigial sideband modulation the selectable output channel frequency shall be selected from CEA-542-B channels 2 through 51 (inclusive), as referenced in CEA-542-B Table 1 column headed “STD 8/16 VSB.” 2CEA-761-B For double sideband modulation the selectable output channel frequency shall be selected
17、 from CEA-542-B channels 3 through 51 (inclusive), as referenced in CEA-542-B Table 1 column headed “STD 8/16 VSB.” The upper sideband shall be on the selected channel. For certain off-air channels, the lower sideband falls on a frequency that is not used for off-air broadcasting. Care should be tak
18、en in selection of frequencies to avoid placement of the lower sideband on a non-television broadcast channel. 3.2 Nominal RMS Output Level The nominal RMS output level shall be -3 dBmV (+6/-3 dB) at 75 ohms. NOTENominal output signal is based on a reduction of 3 to 6 dB from typical NTSC levels. Th
19、e value of 3 dBmV at 75 ohms is equivalent to 51.8 dBm in the entire VSB signal (which includes 0.3 dB for the pilot), or 119.4 dBm/Hz in the data portion of the spectrum. 3.3 Pilot Phase Noise This section addresses pilot phase noise for 8 VSB trellis and 16 VSB. 3.3.1 Pilot Phase Noise-8 VSB Trell
20、is Pilot phase noise shall be less than -90 dBc at 20 kHz for 8 VSB trellis. NOTEThe specification is 12 dB better than the demonstrated threshold of 78 dBc at 20 kHz for 8 VSB (trellis coded) reception. 3.3.2 Pilot Phase Noise-16 VSB Pilot phase noise shall be less than -90 dBc at 20 kHz for 16 VSB
21、. NOTEThe specification is 7 dB better than the demonstrated threshold of 83 dBc at 20 kHz for 16 VSB reception. 3.4 Error Vector Magnitude (EVM) The specifications for EVM follow. For a definition of EVM and further information, see ATSC A/64A. 3.4.1 EVM-8 VSB Trellis The EVM, in instances without
22、equalization, shall be at least 18 dB below the measured output power for 8 VSB trellis. NOTEThe specification is set to allow simple filtering without phase correction in the remodulator, while leaving sufficient tolerance for additional linear distortion due to home wiring. The EVM, in instances w
23、ith equalization, shall be at least 24 dB below the measured output power. NOTEThe specification effectively sets a limit on non-linear distortions in the remodulator. 3.4.2 EVM16 VSB The EVM, in instances without equalization, shall be at least 32 dB below the measured output power for 16 VSB. NOTE
24、The specification is set to allow simple filtering without phase correction in the remodulator, while leaving sufficient tolerance for additional linear distortion due to home wiring. The EVM, in instances with equalization, shall be at least 34 dB below the measured output power for 16 VSB. 3CEA-76
25、1-B NOTEThe specification effectively sets a limit on non-linear distortions in the remodulator. 3.5 Connector The connector shall be an F-type female connector per IEC 60169-24 (1991-11) or per ANSI/SCTE 02 2006. 3.6 Side-band Output The output signal shall have the signal characteristics as specif
26、ied in Section 3.6.1 or 3.6.2. 3.6.1 Double Sideband Specification Nominal double sideband transmission spectrum shall be as indicated in Figure 1. All spurious signals that are greater than 12 MHz from the pilot of the desired channels output signal shall be more than 36 dB down from the actual sig
27、nal level. Double sideband is intended for applications where there are no other adjacent signals. When double sideband modulation (as indicated by the solid curve in Figure 1) is used, the actual emission appearing on frequencies removed by more than 4.6 MHz below or 7.4 MHz above the pilot frequen
28、cy shall be attenuated at least 30 dB (as indicated by the dashed curve in Figure 1), for example, by means of filtering or processing. Pilot+7.4 MHz-4.6 MHzTransmittedChannel6 MHz BWUnusedLowerSide-band-30 dBFigure 1 Double Sideband Transmission 3.6.2 Vestigial Sideband Specification Attenuation ou
29、tside of the 6 MHz channel shall be attenuated by at least 36 dB. See Figure 2. 4CEA-761-B -36 dBFigure 2 VSB Channel Occupancy 3.7 Data and Clock Rates Data and clock rates should be as indicated in Table 1. Table 1 Data and Clock Rates VSB Mode IRC (Interface Reference Clock) Input Data Rate Bits
30、per sec (bps)1Input Data Rate Bytes per sec (Bps)216 VSB 5,381,118 38,785,317 4,848,164 8 VSB Trellis 2,690,559 19,392,658 2,424,082 4 On-Screen Display (OSD) Support Figure 3 illustrates a typical OSD system. 1Includes MPEG2-TS packet sync byte (0x47). The effective bit rate, not including MPEG2-TS
31、 sync byte is 19,289,506 bps and 38,579,012 bps. 2The input data rate is not an integral number of Bps. The actual Bps is derived from the bit rate. The values in this table have been rounded. 5CEA-761-B Source Device (DVCR, DVD, satellite box, cable box, etc.) DTV Valid ATSC Transport OSD Generator
32、 Demux OSD Interpreter Valid ATSC Transport Stream DemodRemod Mux Figure 3 Typical OSD System Illustration 4.1 OSD Encapsulation OSD data shall be encapsulated in PES packets, which are then converted to MPEG-2 transport stream packets. See Figure 4. OSD OSDHeader DataPartition #1Transport Stream pa
33、cketsPartition #2PESHPESHFillTSHTSHTSHTSHFigure 4 OSD Data Packet Illustration 4.1.1 PES Encapsulation The following restrictions shall apply: a) stream_id is defined as 0xBF to indicate that this stream shall be of type private_stream_2. b) OSD data shall be carried as the payload of PES packets id
34、entified by PID 0x1FFD. c) Each OSD subframe shall start a new PES packet. d) The OSD subframe may be transported in more than one PES packet. In addition, the Transport Stream packets that result from PES segmentation shall conform to the following constraints: a) transport_scrambling_control bits
35、shall have the value 00. b) adaptation_field_control bits shall have the value 01. For a detailed description of PES encapsulation, see ISO/IEC 13818-1, as constrained by ATSC A/53E. 4.1.2 Syntax and Semantics for PES Packets carrying OSD Information The syntax and semantics for a PES packet carryin
36、g OSD information shall be as defined in Table 2. 6CEA-761-B Table 2 PES Packet Definition for Carrying OSD Information Bits Format OSD_PES_packet( ) start_code_prefix 24 Bslbf stream_id 8 0xBF PES_packet_length 16 Uimsbf total_partitions 8 Uimsbf partition_number 8 Uimsbf version_control 5 Uimsbf p
37、rotocol_id 3 Uimsbf additional_info_length 8 Uimsbf if (additional_info_length 0) additional_info( ) var OSD_data( ) var Reserved 32 rpchof Where: start_code_prefix - is a 24-bit field that identifies the beginning of a packet. Its value shall be set to 0x000001. stream_id - is an 8-bit field that s
38、hall be set to 0xBF (private_stream_2) to indicate that the format of the OSD PES packets follows a privately defined protocol. PES_packet_length - is a 16-bit field specifying the number of bytes in the PES packet immediately following this field to the end of the PES packet. The value of this fiel
39、d shall not exceed 65529 (equivalently, the maximum size for an OSD PES packet is 65535 bytes). total_partitions - is an 8-bit field that specifies the total number of partitions required to carry the OSD datagram using fixed length PES packets. The range for this field shall be between 1 and 255 (i
40、nclusive). partition_number - is an 8-bit field that specifies the OSD partition carried in this PES packet. The range for this field shall be between 1 and 255 (inclusive). version_control is a 5-bit field that identifies the version number of the transmitted OSD. Its value increases by one every t
41、ime a new OSD subframe is generated and transmitted. If the same subframe is retransmitted, then this value is not incremented. Upon reaching the value 31, it wraps around to 0. protocol_id - is a 3-bit field that is currently defined as 000. All other values are reserved for future eventual additio
42、ns and/or restructuring of the OSD protocol. additional_info_length - is an 8-bit field the value of which corresponds to the length in bytes of the additional_info field. additional_info is a field designated to contain additional information that may be added eventually in the future by CEA. Curre
43、ntly, no additional information exists and therefore the value of the field additional_info_length is 0x00. OSD_data - is a subframe header. It may contain data if necessary. 7CEA-761-B 4.1.3 Maximum Transmission Rate for OSD Data The maximum transmission rate for OSD data shall not exceed 19.29 Mbp
44、s3averaged over any 100 ms interval. This rate shall be further constrained by the requirement that the solid color fill region subframes shall not be transmitted more frequently than fully expanded subframes. Further, the OSD source shall pause between transmission of a solid color fill region subf
45、rame and the next subframe to permit the subframe to be expanded. Even though the solid color fill region subframe may be smaller in size than the fully expanded subframe, the processing time required in the OSD consumer device is the same. The time in seconds (TS) required to transmit the fully exp
46、anded subframe may be calculated as follows: Step 1: Subframe Width x Subframe Height4x # bits/pixel = TbStep 2: Tb/ 19.29 Mbps = TsWhere: Ts=time in seconds Tb=total bits to be transmitted Example calculations follow: A) A 640 x 480, 4-bit solid color fill region subframe Step 1: 640 x 480 x 4 = 1.
47、23 Mb Step 2: 1.23 Mb / 19.29 Mbps = 63.8 ms Therefore the OSD source shall pause 63.8 ms after the transmission of the first solid color fill region subframe before another subframe is transmitted. B) A 300 x 200, 16-bit solid color fill region subframe Step 1: 300 x 200 x 16 = 0.96 Mb Step 2: 0.96
48、 Mb / 19.29 Mbps = 49.8 ms Therefore the OSD source shall pause 49.8 ms after the transmission of the first solid color fill region subframe before another subframe is transmitted. If the OSD producer is making use of the double buffering feature, then it shall not assume a frame rate faster than 24
49、 frames per second. 4.1.4 Retransmission Recommendation The consumer device should retransmit the OSD within 1 second if there has been no change to the OSD. 5 OSD Data OSD data characteristics shall conform to the normative elements of CEA-799-A. For Set_OSD_pixel_format purposes, CEA-799-A Sec. 3.4.1 states: Processing the first Set_OSD_pixel_format subframe aft
