1、DRAFT FOR DEVELOPMENTDD IEC/TS 62312-1-1:2008Guideline for synchronization of audio and video Part 1-1: Measurement methods for synchronization of audio and video equipment and systems GeneralICS 33.160.01g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49
2、g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58DD IEC/TS 62312-1-1:2008This Draft for Development was published under the authority of the Standards Policy and Strategy Committee on 30 September 2008 BSI 2008ISBN 978 0 580 62713 2National for
3、ewordThis Draft for Development is the UK implementation of IEC/TS 62312-1-1:2008.This publication is not to be regarded as a British Standard.It is being issued in the Draft for Development series of publications and is of a provisional nature. It should be applied on this provisional basis, so tha
4、t information and experience of its practical application can be obtained.Comments arising from the use of this Draft for Development are requested so that UK experience can be reported to the international organization responsible for its conversion to an international standard. A review of this pu
5、blication will be initiated not later than three years after its publication by the international organization so that a decision can be taken on its status. Notification of the start of the review period will be made in an announcement in the appropriate issue of Update Standards.According to the r
6、eplies received by the end of the review period, the responsible BSI Committee will decide whether to support the conversion into an international Standard, to extend the life of the Technical Specification or to withdraw it. Comments should be sent to the Secretary of the responsible BSI Technical
7、Committee at British Standards House, 389 Chiswick High Road, London W4 4AL.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, video and multimedia systems and equipment.A list of organizations represented on this committee can be obtained on request to its
8、secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Amendments/corrigenda issued since publicationDate CommentsIEC/TS 62312-1-1Edition 1.0 2008-03TECHNICAL SPECIFICATIONGuideline for synchronization of
9、audio and video Part 1-1: Measurement methods for synchronization of audio and video equipment and systems General DD IEC/TS 62312-1-1:2008CONTENTS INTRODUCTION.3 1 Scope.4 2 Normative references .4 3 Terms and definitions .4 4 Measuring conditions4 4.1 General conditions 4 4.1.1 Power supplies 4 4.
10、1.2 Environmental conditions.5 4.2 Specific conditions 5 4.3 General settings 5 4.4 Specific settings 5 5 Measurement methods .6 5.1 General block diagram 6 5.2 Test signal source and test signal .6 5.2.1 General .6 5.2.2 Signal generator 6 5.2.3 Test disc6 5.3 EUT.7 5.3.1 Equipment .7 5.3.2 Compoun
11、d equipment8 5.4 Measuring instruments 9 5.4.1 General .9 5.4.2 Measurement of signal 9 5.4.3 Measurement of reproduced signal9 5.4.4 Specific requirement10 Annex A (informative) Assessment of the result of measurement .11 Bibliography12 Figure 1 General block diagram for measurement 6 Figure 2 Audi
12、o and video device 7 Figure 3 Source device 8 Figure 4 Display device8 Figure 5 Recorder device.8 Figure 6 Compound equipment 9 Figure 7 Measurement of reproduced signal 10 2 DD IEC/TS 62312-1-1:2008INTRODUCTION Audio and video equipment processes or reproduces the input signals of audio and video,
13、then outputs these signals in various forms. Audio and video equipment needs time to process or reproduce the input signal. This time depends on the signal format, the architecture of equipment and the design of equipment. Hence audio and video equipment may have different output delays for audio an
14、d video signals, and this causes unsynchronised audio and video outputs. This Technical Specification is the general part of the measurement method for that time difference between audio and video outputs. The other subparts of IEC/TS 62312-1 describe specific measurement methods for specific audio
15、and video equipment. 3 DD IEC/TS 62312-1-1:2008GUIDELINE FOR SYNCHRONIZATION OF AUDIO AND VIDEO Part 1-1: Measurement methods for synchronization of audio and video equipment and systems General 1 Scope This part of 62312 gives guidelines for methods of synchronization of audio and video. This Techn
16、ical Specification describes general measurement methods for the synchronization of audio and video equipment. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated reference
17、s, the latest edition of the referenced document (including any amendments) applies. IEC/TS 62312-2, Guideline for synchronization of audio and video Part 2: Methods for synchronization of audio and video systems 3 Terms and definitions For the purposes of this document, the following terms and defi
18、nitions apply. Also the terms and definitions given in IEC 62312-2 apply. 3.1 EUT equipment under test 4 Measuring conditions 4.1 General conditions 4.1.1 Power supplies 4.1.1.1 Voltage The supplied AC power voltage shall be the fixed value of the region where the equipment under test is used. The s
19、upplied DC power voltage shall be the fixed value specified by the manufacturer. The tolerance shall be within 1 % in both cases. If this tolerance does not affect the results of measurement, the tolerance can be within 5 %. 4.1.1.2 Frequency The frequency of the AC power supply shall be 50 Hz or 60
20、 Hz and the fluctuation shall be within 2 %. 4 DD IEC/TS 62312-1-1:20084.1.1.3 Waveform distortion 4.1.1.3.1 AC power supply The waveform of the AC power supply shall be a sine wave in which the harmonic content is 2 % or less. 4.1.1.3.2 DC power supply The ripple voltage shall be 0,1 % or less. 4.1
21、.2 Environmental conditions 4.1.2.1 Environmental air condition The environmental conditions for measurements shall be: Ambient temperature: Relative humidity: Air pressure: 20 C + 15 C 5 C 60 % 15 % 96 kPa 10 kPa 4.1.2.2 Warm up The equipment under test shall be powered on 5 min before starting the
22、 test. It may be zero if the warm up does not affect the results of measurement. 4.1.2.3 Initialization The equipment under test shall be initialized before starting the test. 4.2 Specific conditions If specific conditions are required for the measurement of equipment, these conditions shall be spec
23、ified. NOTE The other subparts of IEC 62312-1 specify the measurement method for the specific equipment, the special conditions may be specified in that part. 4.3 General settings General settings for equipment shall be set to the default setting which is specified by the manufacturer, normally cent
24、re position. If there will be no special indication and the functions that affect the results of measurement, all of the controllers shall be switched off. 4.4 Specific settings If specific equipment has its own specific settings, it shall be set to have the results of measurement regarding the spec
25、ific settings. The other subparts of IEC 62312-1 specify specific settings for specific equipment. 5 DD IEC/TS 62312-1-1:20085 Measurement methods 5.1 General block diagram Test signal source EUT Measuring instruments Audio Video Inputs Outputs Audio VideoIEC 346/08 Figure 1 General block diagram fo
26、r measurement The test signal source provides the reference audio and video signal. There is either no time difference between them or the difference is specified. These audio and video test signals are applied to EUT in appropriate method for each EUT. The EUT reproduces or processes these test sig
27、nals and outputs the audio and video signals. The measuring instruments measure the output from the EUT and measure the time difference between audio and video outputs from the EUT. 5.2 Test signal source and test signal 5.2.1 General The test signal source provides audio and video test signals as a
28、 reference signal for measuring. The content, format and media of the test signal are different depending on the EUT. The basic format of the test signal content consists of synchronized audio and video signals that are used as a reference for synchronization and are processed or reproduced by EUT.
29、The EUT outputs the resulting signal to the measuring instruments. The output signal should be detectable and be able to be measured by the measuring instruments. To conform to this requirement, the test signal content should be made suitable for the measuring instruments. The form of the test signa
30、l is an electrical signal or a signal recorded on media. The format and media of the test signal should be appropriate for EUT. This would normally be the default format and media appropriate to the functionality of EUT. 5.2.2 Signal generator Where a signal generator is applied to an EUT that has a
31、 signal input, the format of output signal of the signal generator should be appropriate for EUT. The signal will be input through an appropriate signal interface on the EUT. 5.2.3 Test disc Where a test disc is applied to EUT that is a disc player, the test disc format should be appropriate for EUT
32、. 6 DD IEC/TS 62312-1-1:20085.3 EUT 5.3.1 Equipment 5.3.1.1 General In this Technical Specification, the EUT is an audio and video device that consists of audio and video units. Each unit includes latency and delay. The model of audio and video device is defined in IEC 62312-2. Figure 2 shows a simp
33、lified model of an audio and video device based on the definition of IEC 62312-2. Audio and video device Audio Video t1+ TLv+ TDvt1+ TLa+ TDaTLv+ TDvTLa+ TDaInputs Outputs t1AudioVideoIEC 347/08 The total latency and the delay of the audio and video device are defined. Key TLvis the total latency of
34、 video TDvis the total delay of video TLais the total latency of audio Tdais the total delay of audio Figure 2 Audio and video device Latency and delay are defined in Clause 3 of IEC 62312-2. The audio and video device reproduces or processes the input signal, and this causes delay and latency. From
35、 the input to the output, the total delay and the total latency are caused in each of audio and video signals. The audio and video signals are input to the audio and video device at the time t1, the total latency and delay are added to this to form the audio and video output signals. The outputs fro
36、m the source device are audio and video signals in analogue or digital form. 5.3.1.2 Category of audio and video device 5.3.1.2.1 Source device Audio and video devices are categorized into specific types of devices. Figure 3 shows the source device and the signal source which is the input to the sou
37、rce device. The signal source can be in various forms. In case of disc player, disc is a signal source. In case of tuner, received and decoded broadcasting signal is a signal source. 7 DD IEC/TS 62312-1-1:2008Source device AudioVideo Signal source Outputs Audio Video TLa+ TDaTLv+ TDvt1+ TLv+ TDvt1+
38、TLa+ TDat1IEC 348/08 Figure 3 Source device 5.3.1.2.2 Display device Figure 4 shows the display device. The outputs from this device are audio and video signals reproduced as sound and visual images realized by a display unit and speakers. Display device Audio Video Speakers Display unit Video drive
39、r Audio driver Inputs TLv+ TDvTLa+ TDat1t1+ TLv+ TDvt1+ TLa+ TDaIEC 349/08 Figure 4 Display device 5.3.1.2.3 Recorder device Figure 5 shows the recorder device, the audio and video signals are recorded on the storage and these signals are played and then output. The total delay and latency are the s
40、ums of each of the total delay and latency of the recording part and the playback part, as identified by suffix R for the recording part and P for the playback part. In order to measure the recording part delay, the monitor outputs are used. Recorder deviceStorage Outputs (TLv+ TDv)P(TLa+ TDa)P(TLv+
41、 TDv)R(TLa+ TDa)RAudio Video Inputs t1+ TLv+ TDvt1+ TLa+ TDat1Recording part Playback partMonitor outputs Audio Video IEC 350/08 Figure 5 Recorder device 5.3.2 Compound equipment Equipment may consist of multiple audio and video devices. Generally the EUT is defined as the device between the first i
42、nput and the final output. When it is required to measure the EUT from the second or later input to before the final output, those inputs and outputs should be 8 DD IEC/TS 62312-1-1:2008the subject of measurement. Figure 6 shows compound equipment that consists of multiple (n devices) audio and vide
43、o devices. For instance, equipment such as a TV with a video recorder consists of TV tuner as a source device, recorder device and display device. First outputsAudio Video First inputs t1+ (TLv+ TDv)1t1+ (TLa+ TDa)1t1nthinput Audio and video device 1 (TLv+ TDv)1(TLa+ TDa)1Audio and video device n (T
44、Lv+ TDv)n(TLa+ TDa)nFinal outputs t1+ (TLv+ TDv)1+ + (TLv+ TDv)nt1+ (TLa+ TDa)1+ + (TLa+ TDa)nn = 1, 2, 3, . Audio Video Audio Video Audio Video IEC 351/08 Figure 6 Compound equipment 5.4 Measuring instruments 5.4.1 General The audio and video device outputs audio and video signals with the total va
45、lues of latency and delay as shown in Figure 2. The measuring instruments should have a capability to measure the timing of the output signal, that is a processed or reproduced signal of the input signal. The measuring instruments measure the value of the difference between them, or, a calculation g
46、ives the difference, the value is: Td= (t1+ (TLv+ TDv) (t1+ (TLa+ TDa) = (TLv+ TDv) (TLa+ TDa) where Tdis a time value that indicates the total latency and delay of the video against the audio. 5.4.2 Measurement of signal The forms of output signals are analogue or digital. When it is in analogue fo
47、rm, the measuring instruments are a video analyser, audio analyser or oscilloscope. When they are in digital form, they are signals in a digital interface. The signal format of a digital interface will be a specific format depending on each interface format. The measuring instruments should have a c
48、apability to measure these signals. 5.4.3 Measurement of reproduced signal To measure the output of the reproduced audio and video signals, measuring instruments should have a capability to measure sound and visual images. 9 DD IEC/TS 62312-1-1:2008To measure sound, an acoustic to an electrical (A/E
49、) transducer is applied. If the acoustic spatial delay is out of the subject of the measurement, the electrical signal of the audio is applied to measure sound. To measure visual image, an optical to electrical (O/E) transducer is applied. The O/E transducer senses the visual image on the display unit. Which part of the visual image should be the subject of the measurement depends on the test signal contents. Oscilloscope or other measuring instruments are used to measure these converted electrical s
