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HDMI Licensing, LLC

HDMI Interoperability Principles, Practices and Tools Neal Kendall Marketing Manager. HDMI Licensing, LLC . September 18, 2009. 大家好，我叫 Neal Kendall ，我是 Quantum Data 的市场拓展经理。 Hi my name is Neal Kendall I am a marketing manager for Quantum Data.

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HDMI Licensing, LLC

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  1. HDMI Interoperability Principles, Practices and Tools Neal Kendall Marketing Manager HDMI Licensing, LLC September 18, 2009 大家好，我叫Neal Kendall，我是Quantum Data的市场拓展经理。Hi my name is Neal Kendall I am a marketing manager for Quantum Data. 很荣幸来到这里，也感谢你们来参与。It is an honor to be here and I thank you for attending. 我将谈谈HDMI的互通性问题。I am going to talk about HDMI interoperability.

  2. For updates to this presentation visit our web site: www.quantumdata.com and go to: www.quantumdata.com/downloads/HDMI_2009.asp Please visit our booth in the HDMI TechZone HDMI Licensing, LLC September 18, 2009 需要更多关于这个讲解的材料，请登录我们的网站:For updates to the presentation please visit our website (I will show this link again at the end.) 同时，欢迎进入我们的客户空间HDMI TechZoneAlso, please be sure to visit our booth in the HDMI TechZone.

  3. HDMI Interoperability – Topics Principles to ensure success What solutions do developers need to ensure HDMI interoperability? Interoperability issues - Sample cases. HDMI 互通性 – 主题HDMI Interoperability – Topics 以下是我今天要讲解的主题…Here are the topics I will be covering in the presentation… 互通性实现理论Principles to ensure success. 研发者需要什么解决方法来保证HDMI的互通性？What solutions do developers need to ensure HDMI interoperability? 我们制作HDMI的检测设备，用于检查产品是否符合HDMI通讯协议和应用层…We make test equipment that works at the protocol and application layer… …—不是HDMI硬件的物理层。…of HDMI—not the physical layer. 我们解决你们这样的研发者的产品输入互通性的问题。The solutions we provide are based on input from developers like yourselves. 研发者需要检测互通性的功能，来保证他们的产品可以广泛地工作。Developers request test functions that help them ensure interoperability in the broadest sense. 互通性问题-案例Interoperability issues - Sample cases.

  4. HDMI Interoperability – Principles to Ensure Success Compliance Test HDMI/HDCPPlug Fest In-HouseInterop Test • HDMI and other specifications: • CEA-861E. • HDCP. • IEC for audio (60958, 61937) • HDMI compliance testing: • Compliance test specification. • HDMI LLC Authorized Test Centers. • HDCP Authorized Test Centers. • CEA Plug Fests. • In-house “ad hoc” interoperability testing because compliance does not ensure interoperability. Why? • Complexity. • Variety of products. • Many first generation products deployed. Prototype Device Compliant Device Interop Tested Ready for commercial launch HDMI互通性-保证互通性实现的理论HDMI Interoperability – Principles to Ensure Success \如果你想要保证你的HDMI产品能够互通于其他的HDMI产品，…If you want to ensure that your product or silicon interoperates with other HDMI… …你需要遵照这些高水平的步骤。…devices you need to follow these high level steps. 你需要查看有关HDMI的规范条款比如：You will need to review the (specifications related to) HDMI. HDMI和其他规范说明：HDMI specification. CEA-861E (from which many of the HDMI specifications are derived.) HDCP. IEC的声频规范IEC for audio (60958, 61937). 你需要查看HDMI符合性检测规格…You will need to review the HDMI compliance test specification and pass the… …并需要在HDMI ATC机构通过这些检测。…HDMI compliance test at the HDMI ATCs. 你还需要查看并且通过HDCP符合检测并符合其规范。And you will need to review and pass the HDCP compliance test as well. 通过HDCP符合检测并不能保证你的产品具备互通性，但它能使你的产品得到认证。Passing the HDCP compliance test will not help ensure interoperability but it will keep you legal. 参加每年的端口互通性检测集会（Plug Fests）是很重要的。It is important to participate in the plug fests held annually. 这能保证你的新HDMI设备和产品These enable you to connect your new HDMI devices and products to devices… 能够互通于其他卖主的相关设备和产品。…and products of other vendors to see if they interoperate. 最后，因为市场上的设备的复杂性和多元性，…Finally, because of the complexity and variety of products out in the field already,… …你需要进行一些步骤的互通性检测。…you will need to take further steps to test for interoperability. 这些增加的检测在本企业内部进行。This additional testing is conducted in-house.

  5. Ensuring HDMI Interoperability - What Developers Need? 确保HDMI的互通性—研发者需要做什么？ • Ensuring that your product is interoperable with other HDMI devices is critical to the commercial success of your product.确保你的产品与别的HDMI产品互通性是市场的苛刻要求，也是你的产品成功的保证。 • Our (Quantum Data’s) role in helping to ensure interoperability in the HDMI ecosystem is to provide the following types of solutions.我们的角色是向研发者提供保证产品在HDMI系统内实现互通性的一系列解决方法： • Providing approved compliance test tools for pre-compliance in house testing. 提供符合性检测工具用以在企业内做提前的符合性检测 • These solutions are: TMDS, EDID, HDCP, CEC 这些检测解决的问题包括：TMDS, EDID, HDCP, CEC

  6. Ensuring HDMI Interoperability - What Developers Need? • Interoperability test tools should provide the following: • 互通性检测工具将提供以下检测： • Visibility into the HDMI protocol. • HDMI协议的清晰度： • - Monitor and log data island packets. • 监测和记录数据岛数据包 • - Provide timestamps for data island packets. • 为数据岛数据包提供时间标记 • - Ensure packets arrive at the correct interval. • 确保数据包于正确的间隔时间到达 • - Ensure packets arrive at the correct time in relation to other packets. • 确保每个数据包与其他有关的数据包在正确的时间到达 • - Identify where the packets are located in the frame (which line, pixel). • 识别数据包位于框架的哪个位置（哪一行，哪一像素） • - Keep track of when packet values change. • 追踪记录数据包数据值的变动 • - Ensure that packet data values are correct. • 保证数据包数据值正确 • - Ensure that packet data values are consistent with other related values. • 保证数据包数据值与其他相关数据值保持一致

  7. Ensuring HDMI Interoperability - What Developers Need? • Measure video timing.测量视频时序 • Check for pixel anomalies.检查像素的异常反应 • Verify the keep out region.核实未用空间大小 • Monitor and analyze HDCP transactions and related events.监测和分析HDCP的执行和相关事件 • Monitor CEC transactions especially for addressing and routing.监测CEC执行尤其是编址和路由 • Monitor EDID transactions.监测EDID的执行

  8. HDMI Interoperability - Sample Cases Here is a list of sample cases that I am going to cover in the presentation.HDMI互通性-案例 - 以下是我在讲解 For (some of the cases – where necessary) I will provide background information about how a particular HDMI function works. 对于每一个案例，我将提供一些背景资料来展示它在特定的HDMI功能下是如何工作的。 Then I will provide descriptions of the test solutions that developers have ask us to provide. 然后我将解释研发商们要求我们提供的与之相关的检测和解决方法。 • Lipsync Lipsync（视频音频同步） • Video视频 • Control – CEC Cases控制-CEC案例 • HDCP Cases HDCP案例 • Audio Cases音频案例 • AVMute AVMute（静音）

  9. High Definition Content Protection (HDCP)高带宽数字内容保护技术(HDCP) Audio音频 AVMute音频视频静音 Lipsync音频和视频的同步 Video视频方面 Consumer Electronic Control (CEC)消费电子控制

  10. HDCP Interoperability Issues We have been told by developers in the industry that HDCP is: “The hardest thing about HDMI interoperability.”我们已经被很多企业的研发商告知，HDCP是： “在HDMI中最难解决互 通性问题的部分。” (This is) mainly because HDCP compliance testing and (HDMI) interoperability testing goals are different. 主要因为HDCP符合性检测和互通性检测的目的不一样。 The goal of HDMI interoperability testing is to ensure content is rendered on a display. HDMI互通性检测是为了保证内容提供给播放设备。 Content protection is intended to prevent copying of digital audio and video content.HDCP所含的保护内容是为了防止数字音频和视频内容被复制。

  11. HDCP Interoperability Issues HDCP uses authentication to prevent non-licensed devices from receiving high value content.它使用验证方式来防止没有认证许可的设备接收高清晰内容。 HDCP uses encryption to prevent eavesdropping. HDCP使用加密码的方式来防止窃取数据。 And it uses key revocation to ensure that devices that have beencompromised cannot receive content.并且它用密码失效的方式来保证没有认证设备的设备接收不到内容。 HDCP is complex and there is a wide variety of devices installed in homes, old & new and from a variety of suppliers. HDCP很复杂，不同家庭里里有很多不同的设备，老的、新的，它们 自不的供应商。 Developers have requested a variety of tools to help address HDMI interoperability problems related to HDCP.开发商要求我们提供多样的工具来帮助他们解决HDMI的HDCP的互通 问题。

  12. HDCP – How it Works Status (Hot-plug,Connection, & Power)+ Info (BKSV & Bcaps) Status (Hot-plug,Connection, & Power)+ Info (BKSV & Bcaps) Source Repeater Sink High-Value Content (ICT- flag = TRUE) Presentation Device Visual Image HDCP Receiver HDCP Receiver HDCP Transmitter HDCP Transmitter Media Decrypt Decrypt Encrypt Encrypt Audible Sound HDCP Content (ciphered) HDCP Content (ciphered) HDCP Content (deciphered) • This is a high level depiction of how HDCP works given a network with source a repeater and a sink device.这里大概介绍一下HDCP如何与信号源、重发器以及接收器等联网工作。 • When high value content is present, HDCP authentication begins.当HDCP解码后，高质量的内容就出现了。 • This can also be initated when a hot plug occurs.当一个热插拔出现后HDCP认证开始初始化。 • Once authentication is completed, the content is encrypted from the source.一旦验证完成，高质量内容将从信号源被加密。 • It is (then also) decrypted at the repeater and then re-encrypted and passed on to the far end display device.到达重发器，内容则被解密，然后再被加密并送到最终端的显示设备。

  13. HDCP Interoperability – Unencrypted Video Some devices do not make HDCP registers available until seeing a stable clock delivered. Send unencrypted video into downstream device before reading HDCP registers. 根据规范，接收器必须接收到至少一个数据岛。According to the spec, the sink has to see at least one data island (before initializing its HDCP registers)… 这仅仅要求一或者两帧（frame）未加密的视频。…this would require only a frame or two of unencrypted video. 一些设备还没看到稳定的像素时脉前，说明他们的HDCP注册还没有完成。Some devices do not make their HDCP registers available until seeing a stable pixel clock. 最好发送几帧(frame)未加密的视频。It is best to send several (at least 30) frames of unencrypted video (prior to initiating authentication). 这能保证下游的设备的HDCP完成注册。This ensures that the downstream device’s HDCP registers are ready. 在这种情况下，只有少量帧（frame）被传输。In this case (above) only a few frames are sent. The source reads the EDID and looks for the CEA block and the HDMI vendor specific data block. The source is not suppose to initiate HDCP with HDMI unencrypted video unless it sees the… …vendor specific data block in the EDID.

  14. EDID EDID BSTATUS HDCP Authentication – Reading BSTATUS AVR TV STB 5V 5V HP HP 3 – Source begins authentication by reading BSTATUS. Checks for HDMI mode. 信号源读到BSTATUS或者BCAPS注册就开始认证程序。The source reads the BSTATUS register or the BCAPS to begin the authentication process. 一读到BSTATUS注册，信号源就检查到这个下游设备是不是HDMI格式。Reading the BSTATUS is done by the source to check if the down stream device is in the HDMI mode.

  15. EDID EDID BCAPS HDCP Authentication – Reading BCAPS AVR TV STB 5V 5V HP HP BSTATUS 4 – Read BCAPS. Checks for Repeater bit. 当信号源读到BCAPS登陆，它会检查这个下游设备是不是一个重发器。The source reads the BCAPS register to check if the down stream device is a repeater or not.

  16. HDCP Interoperability – Reading BCAPS BCAPS not read before reading Ro’value. 当系统中有一个重发器的情况下如果BCAPS值没被读取到，将会发生错误。In some cases, when there is a repeater in the system, if BCAPS is not read, there could be an error. 原因是，BCAPS 包含的就绪元位（repeater bit） 值被用来计算Ro值。The reason is that the BCAPS Repeater bit is used in the calculation of Ro. 这里有一个例子，BCAPS在HDCP第一步认证中没有被读到。Here is a case where BCAPS is not read during Part one of HDCP authentication. 结果是Ro值不符合，认证失败。 The result is that the Ro values do not match and authentication fails.

  17. EDID EDID BCAPS BKSV HDCP Authentication – Reading BKSV AVR TV STB 5V 5V HP HP 5 – Read BKSV. Must be 20 ones and 20 zeros. 当信号源读到其下游设备的BKSV。The source reads the BKSV of the downstream device. 这个BKSV是一个有个40比特（bit）的数字，其中包含20个“1”和20个“0”The BKSV is a 40 bit number that has to have 20 ones and 20 zeros. 这个BKSV数字的40比特（bit），用来选择哪个专用密匙（每个密匙数字为56比特）被使用，这些The BKSV is used to select which of the 40 56 bit device private keys are used to calculate Ro. 选出的密匙用来计算Ro。 (Read the BKSV a second time if the first one fails.)

  18. EDID EDID BCAPS AN AKSV BKSV HDCP Authentication – Writing AKSV AVR TV STB 5V 5V HP HP 6 – Write An and AKSV. KSV Must be 20 ones and 20 zeros. 信号源发出An值给下游设备。The source writes the An value to the downstream device. An是一个64比特（bit）的随意比特（bit）值，每次HDCP认证时都产生一个新数据，这新数据被用来计算Ro.The An is a 64-bit pseudo random bit value generated new for each authentication & is used in the calculation of Ro. 信号源也会发出它的AKSV数据给下游设备。 The source also sends its AKSV to the downstream device.

  19. HDCP Interoperability – Reading Ro Wait at least 100ms after writing AKSV to read Ro. Preferably wait 125ms. HDCP协议要求一个信号源在发送AKSV到接收器后，在读取Ro前，要等100毫秒。The HDCP specification requires that a source wait 100ms after writing AKSV to the sink before reading Ro’. 但是，建议最好设计的时候让这个等待时间比这个长一些。However it is recommended to wait longer than that. 最好等125毫秒。这不是比赛，没必要太急。It is better to wait 125ms. It is not a race. There is no need to rush.

  20. EDID EDID BCAPS AN AKSV BKSV Ro BCAPS AN AKSV BKSV Ro HDCP Authentication – Comparing Ro with Ro’ AVR TV STB 5V 5V HP HP 7 – Read Ro and compare with Ro’. Part one of authentication then occurs downstream as well. 这个两个来自两个设备结算出的Ro结果互相对照。The calculation of Ro is made by both devices and compared with each other. 如果对照结果是准确的，认证的第一部分就完成了。 If the comparison is true, the first part of authentication is complete. 当一个Ri或者V值解读失败，它将被重读，一个初始化错误可能导致I2总线的错误。When an Ri (or BKSV) read fails, reread it (wait ~20ms) ; an initial failure could be an I2C bus error.

  21. BCAPS HDCP Authentication – Read BCAPS AVR TV STB DTV BCAPS 8 – Second part of authentication begins. Read BCAPS. AN AKSV BKSV Ro Waiting for Ready bit to be set. 第二部分的认证开始。The second part of authentication begins. (Image shows that the first part of authentication occurs downstream.) 第二部分认证，是证明这个设备位于重发器的下游位置。The second part of authentation, authenticates the devices that are downstream from the repeater. 这部分从读到BCAPS注册开始，检查就绪元位（Ready bit）的建立，以此指示It begins by reading the BCAPS register to check if the Ready bit is set indicating… 重发器已经收集下游设备的BKSV值。…that the repeater has assembled the downstream BKSV values. 在这里，你可以看到就绪元位（Ready bit）被建立。 Here you see that the Ready bit is set.

  22. BCAPS BSTATUS HDCP Authentication – Read BSTATUS AVR TV STB DTV BCAPS AN 9 – Read BSTATUS. AKSV BKSV Ro Checks for depth, device count parameters. 这个BSTATUS被读到，以此检查重发器深度和设备数量。The BSTATUS is read to check for the depth and device count. 在这里，设备数量是1，重发器深度是1.Here the device count is 1 and the depth is 1.

  23. BCAPS BSTATUS KSV FIFO HDCP Authentication – Read KSV FIFO AVR TV STB DTV BCAPS AN AKSV 10 – Read KSV FIFO. BKSV Ro KSVs of all downstream devices. 一旦就绪元位（Ready bit）建立，信号源就从重发器解读KSV列表。Once the Ready bit is set, the source reads the KSV list from the repeater. 在这个案例里，这里只连接有一个设备。 In this case there is only one device (so there is only one downstream KSV in the list).

  24. BCAPS BSTATUS KSV FIFO V HDCP Authentication – Read V and Compare with V’ AVR TV STB DTV BCAPS AN AKSV 11 – Read V and compare with V’. BKSV Ro A V值被信号源和重发器计算，得到的两个值将被做对照。A V value is calculated by the source and repeater and the values are compared. 如果这些值的对照都符合，认证的第二步就完成了。If the values match the second part of authentication is completed.

  25. HDCP Interoperability – Recommended Practices • Empty repeater – setting BCAPS and BSTATUS.不连接电视的重发器-设立BCAPS和BSTATUS。 • Inactive port – continue authentication. 无效端口-继续验证

  26. HDCP – Testing Repeater Behavior for Empty Repeater TV Test instrument emulates a known-good HDCP source. AVR Test Instrument 5V HP EDID Second part of authentication does not occur. BCAPS Source reads BCAPS Repeater bit to determine if second part of authentication is required. 对于检测一个重发器，在没有连接电视的情况下，For testing a repeater for the empty repeater scenario… 一个必须记住的要点是，所有信号源支持BCAPS 值里的就绪位元（Repeater bit）值=0,…it is important to remember that all sources support (cases where) BCAPS Repeater = 0. 但是，不是所有信号源都能支持BCAPS 值里的就绪位元But not all sources support a Repeater bit = 1 with a Device Count of 0. （Repeater bit）值=1，但是显示设备数量（Device Count）为0的情况 BCAPS然而重发器应该被检测，以保证当下游没有显示设备的情况下，他们能设 …Therefore, repeaters should be tested to ensure that they can set the BCAPS… …里就绪位元（Repeater bit）的值为 0。…Repeater bit to 0 when there are no downstream devices.

  27. HDCP – Testing Source Response to Empty Repeater Test instrument emulates an HDCP empty repeater. TV Test Instrument STB 5V HP EDID BCAPS Source reads BCAPS Repeater bit to determine if second part of authentication is required. 检查一个信号源对一个未接电视的重发器的反应。For testing a source device’s response to an empty repeater. 在这个情况下，没有下游设备，或者下游设备没有HDCP认证功能(也就是DEVICE_COUNT=0) 时In the case when no HDCP capable downstream devices (DEVICE_COUNT=0) are connected or active,… 那么如果一个重发器要接受到HDCP的加密内容，它将被看做一个接收器，…then a Repeater is recommended to look like a Sink with its BCAPS repeater bit set to 0… 并且它的BCAPS里的 repeater bit值设为0。…if it wants to receive HDCP protected content. 然而一个信号源应该被检测以保证，当一个重发器设它的BCAPS 里的(But) a source should be tested to verify that it operates properly when a repeater sets its BCAPS Repeater bit to 1… Repeater bit 为0时，信号源能正常工作。 …and the BSTATUS register Device Count set to 0. 在下游设备的KSV为空值时，这个信号源应该被初始化和完成第二部分的HDCP认证。The source should initate and complete the second part of authentication with null values for the downstream KSV. 这个信号源应该在重发器读V值，并且它们所读的V值的对照应该是准确的。 The source should then read the V’ value from repeater and the comparison with its own V value should be true.

  28. HDCP – Testing Source Response to Empty Repeater Test Instrument TV STB Source initiates second part of authentication. 5V HP With no devices downstream KSV list is 0. EDID BCAPS V values are compared to complete the authentication. BSTATUS BSTATUS Device Count of 0. 这里继续检测一个信号源对一个不接电视的重发器，Continuing on here with testing a source device’s response to an empty repeater… 因为这个 repeater bit 进行第二部认证已经被初始化。Because the Repeater bit was set, the second Part of authentication is initiated. 我们看到在BSTATUS登入认证时，设备数为0We see the Device Count of 0 in the BSTATUS register. 在重发器的下游没有设备，这个重发器的KSV FIFO在它的KSV列表里是空值。With no devices downstream from the repeater, the repeater KSV FIFO has null values for its KSV list. 这个信号源应该能冲重发器中读到V值，它们的V值对照应该是准确的。The source should read the V’ value from the repeater and the comparison with its own V value should be true.

  29. HDCP – Testing Source Response to Inactive Port Test instrument emulates a sink, causes hot plug, activates TMDS, presents hot plug assert and EDID but does not enable HDCP ports. Hot plug asserted. EDID is available and read. TV Test Instrument STB 5V Source initiates first part of authentication… HP EDID Source continues attempts to authentication… BCAPS …no acknowledgement on HDCP registers. 这一节讲述如何检测一个信号源的反应，当这个信号源连接到一个不具备HDCP认证的播放设备时。This slide covers how to test a source response to an inactive port on a display. 这里，这个检测工具是模仿一个接收器，它的TMDS运行良好，热插拔出现， EDID数据已经被读取。Here the test equipment is emulating a sink device with its TMDS pairs active, the hot plug asserted, and its EDID available. 然而它的HDCP认证却失效。However its HDCP registers are disabled. 当热插拔出现而EDID数据正常，…As long as the hot plug is asserted and EDID is available,… 信号源应该继续试图初始化HDCP认证。…the source should continue to attempt to initiate HDCP authentication. 这里我们看到，这个信号源继续初始化HDCP认证，Here we see that this source is continuing to initiate HDCP authentication… 不理会HDCP读取要求的失败。…despite the failure to acknowledge the HDCP read requests.

  30. HDCP Interoperability – Summary • Repeaters must forward hot plug pulse when there is a downstream hot plug event, i.e. a TV is plugged in. • 当一个下游设备的热插拔出现，也就是一个TV被插入，重发器将逐个 递热插拔信息到信号源。 • Source devices must respond to hot plugs by initiating HDCP authentication. • 信号源 必须对热插拔做出反应兵开始HDCP认证。 • Source should send thirty (30) frames of unencrypted video to downstream devices prior to attempting HDCP authentication to allow these devices to get their HDCP registers ready.在开始HDCP认证允许这些设备获得HDCP解码前，信号源将发送30帧 加密视 到下游设备。 • Source should read BCAPS initially during first phase of authentication to check that the downstream device’s HDCP registers are initialized.信号源将在认证的第一阶段解读BCAPS初始化。为什么呢？ • 是为了检查下游设备的HDCP注册已经被初始化。 • Because the repeater bit in BCAPS is used in the cipher calculation of Ro. • 有无重发器，决定了repeater bit 在BCAPS里不同值，这个值将被用来 算Ro.

  31. HDCP Interoperability – Summary • When a (BKSV), Ri or V read fails, reread it (wait ~20ms) ; an initial failure could be an I2C bus error.当一个Ri或者V值解读失败，它将被重读，一个初始化错误可能导致I2总线的错误。 • Short reads are not supported by some devices, good practice to avoid them. • 一些设备不能支持迅速读取，最好避免这样的设计。 • Wait at least 100ms after writing AKSV to read Ro. Should wait longer, e.g. 125ms. • 在发送AKSV之后最好等至少100毫秒的时间来读Ro。最好等更长点，比125毫秒。 • Wait required time to read READY bit for V.等待一定时间是为了，V值和就绪元位（ready bit）被计算出来。 • Follow recommended practices when implementing HDCP.当产品执行HDCP时，要遵循行业标准。

  32. High Definition Content Protection (HDCP)高带宽数字内容保护技术(HDCP) Audio音频 AVMute音频视频静音 Lipsync音频和视频的同步 Video视频方面 Consumer Electronic Control (CEC)消费电子控制

  33. Audio InfoFrames Audio Sample Packets Audio Clock Regeneration Channel Status Blocks How Audio Works – Audio Packets Location Audio related packets occur in the vertical and horizontal blanking. Audio infoframe. Audio sample packets. Channel status blocks. Audio clock regeneration. 现在我要谈谈HDMI互通性中关于音频互通性的问题。Now I wanted to turn to HDMI interoperability issues related to audio. 我将简单地介绍一下音频如何工作，然后讨论一些主要的研发商曾经要求我们提供的最可I will provide a brief overview of how audio works and then discuss a few of the key functions developers… 能遇到的不互通的一些问题解决办法。…have asked us to provide to help eliminate interoperability issues most likely to arise. 在HDMI中的音频是如何工作的呢？How does audio work in HDMI? 所有音频数据包——包括音频样本包都被置于框架外的水平消隐和垂直消隐地带。All audio related packets—including the audio sample packets—are placed in the horizontal and vertical blanking. 音频infoframes的发送频率是，至少每框架一次（或者每两个视频field一次）Audio infoframes are sent at least once every frame (or every two video fields [for interlaced formats]). 音频infoframe被发送时，接收器获得音频参数尤其是音箱映射。Audio infoframes are sent to inform the sink about audio parameters especially channel speaker mapping. 音频样本包是发生频率最高的数据包。The audio sample packets are by far the most frequently occurring packets. 他们的发生频率多高取决于音频采样率，通道的数量以及视频格式。How frequently they occur depends on the sampling rate, number of channels and video format. 音频时序重生数据包也发送得很频繁。The audio clock regeneration packets are also sent quite frequently. 音频数据通过HDMI传输时不能保留原来的音频时脉，…Audio data transmitted across the HDMI interface does not retain the original audio sample clock,… …所以它需要在音频设备或者接收器设备（e.g.HDTV）中重生。…so it needs to be regenerated at the audio device or sink device (e.g. HDTV). 音频时脉能得以在接收器中重生，基于从信号源发出的音频时序重生（ACR）…Audio clock is regenerated in the sink based on TMDS clock and N & CTS values sent from… 数据包里的音频采样率和N&CTS值。…the source in the Audio Clock Regeneration (ACR) packets. 最后，包含在音频样本包的有效载荷里的通道状态区块(block)，被分成一系列的192框架（frame）。Finally the channel status blocks, (included in the audio sample packet payload) are spread over 192 frames. 通道状态区块描述音频的格式，采样率，采样深度等。Channel status blocks describe the audio format, sampling rate, bit depth etc.

  34. How Audio Works – Channel Status Blocks 这个通道状态位 (CSB)，在音频采样数据包中，每数据包抽取一个位（bit），每次抽取取够192个位（bit）。The channel status bits (CSB) are accumulated over 192 audio (samples). 这里你能够看到，4个音频采样数据包里只有两个音频数据包被使用在音频帧里。Here you can see that 2 of the 4 (HDMI audio) sample subpackets are populated with audio frames. 每一音频帧有两个子帧，被分别送到不同的两个声道。Each frame has two subframes, one for each channel. 在这个例子里，我们只看到两个声道的 LPCM 音频。In this example, we are just looking at 2-channel LPCM audio. 这个通道状态位（CSB）中，每8个位（bit）构成一个字节（byte），一共24字节（byte）。The channel status bits (CSB) are assembled into 24, 8 bit bytes from 192 frames. 第一字节（byte）里的第一位（bit）决定了这个音频的类型。The audio type is the first bit of the first byte. 在第4字节（byte）的前面（从0到3）的四个位（bit）决定了音频采样率。The sampling rate is defined in bits 0 through 3 of the fourth byte. 在第5字节（byte）里的前面（从0到4）5个位（bit）决定了位深度（bit depth）。The bit depth is defined in bits 0 through 3 of the 5th byte.

  35. How Audio Works – Sample Packetization Audio data packets can have multiple audio samples. E.g. two (2). 这里有一个例子，显示多通道LPCM音频出现在一个HDMI协议分析仪上。Here is an example showing how multi-channel LPCM audio appears in a protocol monitor. 在每个HDMI音频数据包里可以有多个音频样本。There can be multiple samples in each HDMI audio packet. 这里，在这个数据包里有两个音频样本。Here there are two samples (subpackets) shown in this packet.

  36. How Audio Works – Sample Packetization High bit rate audio formats typically have four samples per packet. 高比特率（bit rate）音频格式例如Dolby TrueHD，使用了所有的音频次数据包。High bit rate audio formats like Dolby TrueHD have frames that occupy all subpackets in an HDMI audio sample. 这里是一些例子，显示高比特率（bit rate）音频出现在一个HDMI协议分析仪上。 Here is an example showing how high bit rate audio appears in a protocol monitor.

  37. HDMI Audio Interoperability – What Developers Need Visibility into the audio related packets. 能够在音频数据包里读到数据 - Audio packet location within TMDS stream. 音频数据包在TMDS stream里 - Audio packet rates. 音频数据包率 - Audio packet values. 音频数据包值 ACR - Improper ACR can result in a variety of audio anomalies. ACR—不恰当的ACR会导致多个音频异常现象。 - Measure the accumulated rate at which the ACR packets are transmitted from a source. 当ACR数据包从一个信号源传输出来时，收集每个数据包到达的速。 - Show when the N & CTS values change. 在HDMI分析仪显示ACR中的N & CTS值的变化。 - Verify that N & CTS values are consistent with the sampling rate. 核实N & CTS值与采样率一致。

  38. HDMI Audio Interoperability – What Developers Need Audio samples – Header information. 音频样本—标头（header）信息 - Verify that the sampling rate in the channel status blocks are consistent with other audio meta data and the audio samples. 核实在通道状态区块（channel status blocks）中的采样率与其他音 元数 据（meta data）以及音频样本相一致。 - Verify that the channel status blocks are arriving at 192 audio samples apart. 核实通道状态区块（channel status blocks）是否计数够192个音频采 数包 EDID handling by repeater (e.g. A/V receiver). 重发器（如A/V 接收器）的EDID处理 - Verify that the AVR combines its EDID—substitute its Audio Block with downstream display. 核实AVR包含它的EDID—把下游播放设备的音频数据块替换成它自 的音频数据块

  39. Verify the ACR Packet Rate ACR rate calculated as: ACR rate = ACR packets / timeframe ACR rate = 128 * (Sampling Rate / N) Compare the two values. 1 – Determine number of ACR packets. 2 – Determine timeframe thatACR packets were collected 3 – Determine N value from the ACR packets. 有一些芯片制造商和音频设备制造商曾要求我们解决的一个问题是，One thing that some of the chipmakers and audio device makers have asked for… 检测核实ACR数据包的速度。…is to verify the rate of the ACR packets. 他们想要核实这个速度符合规范。They want to verify that the rate is consistent with the specification. ACR速度展示在这里。The ACR rate is shown here. 在LPCM格式音频中，要知道这个ACR速度，首先你要使用确定的一段时间里的ACR数据包数。For LPCM audio, first you determine rate using the number of ACR packets collected over a timeframe. 然后你可以用这个ACR数据包数值对照采样率，以及N值。Then you could compare this calculated value to the rate determined using the sampling rate and the N value.

  40. Verify the ACR Packet Rate ACR rate calculated as: ACR rate = ACR packets / timeframe ACR rate = 128 * (Sampling Rate / N) Compare the two values. 4 – Determine sampling rate from channel status bits. LPCM的采样率可以从通道状态位（channel status bits）中获得。The sampling rate for LPCM can be obtained from the channel status bits. (You can then make the calculation.)

  41. Verify Audio Sampling Rate Consistency Four ways to check audio sampling rate: From the audio infoframe.从音频infoframe数据包中收集。 From the channel status bits . 从通道状态位（channel status bits）数据包中收集 The sampling rate calculated from the N & CTS values and TMDS clock. 这个音频采样率的数据从N & CTS值和TMDS数据块的计算中得出。 And as calculated from the audio sample packets collected. 这个数据从音频采样数据包的数据计算出来。 一个基本的要求是，在各种数据包中收集一个必要的音频采样率的数据，这个数A common request is to gather the data necessary to allow a comparison… 用以对照其他各种数据包，（看是否每个数据包的这个数据都符合）。…of the audio sampling rate from a variety of sources.

  42. Audio Sampling Rate Consistency - Audio IF Usually the sampling rate bits will be set such that the sampling rate of the audio sample packets in the stream header are used. 这个音频采样率数据有可能显示在音频的infoframe里，…The sampling rate may be shown in the audio infoframes but generally not… 在LPCM和压缩音频的格式中，它infoframe里可能总是空值， …It will always be zeroed out (the sink is instructed to refer to the audio stream header)… …（信号源被指导去查阅音频stream header里的音频采样率数据）。…for LPCM and compressed audio formats.

  43. Audio Sampling Rate Consistency - CSB Audio sampling rate is provided as part of the channel status blocks. 这个采样率总是包含在通道状态位（Channel Status bits)里.The sampling rate is also included in the Channel Status bits. 但这只是在LPCM格式的情况下。But this is only for LPCM. 对于压缩音频，通道状态位（Channel Status bits)总是显示帧速度而非采样率。For compressed audio, the channel status blocks show the frame rate. For Dolby Digital Plus, the frame rate is always 4 times the sampling rate.

  44. Audio Sampling Rate Consistency – ACR Values Calculate audio sample rate based on N & CTS values: Sampling Rate = (TMDS * N) / (128 * CTS) Compare with channel status bits. 1 – Determine TMDS clock. 2 – Determine N & CTS values from ACR packets. 对于LPCM格式，你也可以通过用音频时脉重生数据包的N值和CTS值计算…For LPCM, you can also derive the audio sampling rate through a calculation… …得出音频采样率。…using the N and CTS values of the audio clock regeneration packets. 这个等式使用了TMDS时脉和N&CTS值进行计算。The equation uses the TMDS (not the pixel clock) clock and the N & CTS values. 然后你可以把这个计算出来的值，和通道状态位（Channel Status bits)里的采样率值做比较。You can then compare your calculation with the sampling rate indicated in the channel status blocks.

  45. Audio Sampling Rate Consistency - Samples Audio sample rate calculated as: ASR rate = audio sample packets * audio samples per packet / timeframe 1 – Determine number of audio sample packets transmitted. 2 – Determine timeframe that audio sample packets were collected by looking at the time stamps. 3 – Determine number of audio samples per packet. Only one (1) in this example. 你也可以从音频样本中得到采样率…You can also determine the sampling rate from the audio samples themselves… 但你用这个方法得到采样率，比用LPCM计算出采样率要复杂多了。…but the mechanism to do that goes beyond simple inspection except for LPCM. 用LPCM计算，你可以在一定时期内计算数据包数量。For LPCM you can count the packets collected over a particular period of time. 然后确认每HDMI音频采样数据包的音频样本数量。Then determine the number of samples per HDMI audio sample packet. 这样就得到了计算结果。And make the calculation.

  46. How Audio Works – EDID DTV AV receiver’s Sink EDID EDID (DDC) EDID (DDC) 3 – AV receiver generates hot-plug and the source reads audio data from EDID of AV receiver’s sink side. AV Receiver’s Sink AV Receiver’s Source Audio AV Receiver Source Device 01010101010101010101010101010101010 010101010101010101010101010 Audio/Video(TMDS) Video(TMDS) 1 – Display device generates hot-plug and AV receiver’s source side reads audio from EDID of display. 4 – Source device outputs audio based on the capabilities of the AV receiver’s EDID. 2 – AV receiver incorporates its audio data into the EDID and forwards it to the source device. EDID of DTV • 从显示设备或者重发器中的接收器部分发出的EDID信号通知信号源设备，它能接收什么样的音频格式。EDID sent from display device or sink (Rx) side of audio receiver (repeater) informs the source devices what audio capabilities it supports. • 这一节解释EDID在音频中充当什么角色。This slide shows a depiction of the role of EDID in audio. • 当一个新的设备接入系统下游时，一个热拔插被信号源发现。When a new device is connected downstream, a hot plug pulse is asserted toward the source. • 所有的设备将读到这个下游设备的EDID数据。All devices will read the EDID of the downstream device. • 在这个例子的音频中，DTV的EDID将可能仅仅显示最基本的支持音频…In the case of audio, the DTV’s EDID will probably only show basic audio support,… • …的两个声道，LPCN数据采样率为48kHz。…2 channel, LPCM at 48kHz sampling rate. • 然而一个音频接收器可以支持几个不同的多声道高端音频格式。However an audio receiver will support several different high end audio formats for multi-channel audio. • 但是，如果EDID数据仅简单地从DTV传到信号源，…But if the EDID is simply passed through from the DTV to the source,… • …这个信号源将只发出最基本的两声道。…the source will only put out basic audio. • 因此，如何实现多声道高端音频，这就需要音频系统替换它的DTV的EDID的音频数据块，…So what has to happen is that the Audio system substitutes its audio data block into the EDID… • 再传输这个升级的EDID数据给信号源。…from the DTV and passes the new updated EDID up to the source device. • 信号源于是解读这个EDID并输出，得到例如， 5.1Dolby Digital Plus…The source device then reads the EDID and puts out, for example 5.1 Dolby Digital Plus or… • 或根据这个音频的内容是什么的相映数据……whatever the audio of the content is. (This seemed more common a few years ago on the forums)

  47. Verify AVR Includes its Audio with EDID of Display Typical sink (e.g. HDTV) supports “Basic Audio” in EDID Audio Block. Audio block in the CEA extension block. 一个AV接收器的研发商，可能想要检测…A developer of an AV receiver device may want to test… 他们的AV接收器接收下游播放器的EDID 数据，并用自己的音频数据块……that their product is substituting the audio block for the EDID of the… 替换掉原来EDID里的音频数据块，然后把替换后的数据传输到信号源前， …downstream display device… 检测AV接收器EDID音频数据块替换时的数据。…before passing it upstream to the source device. 在播放设备直接连接信号源时，使用一个EDID编辑器/浏览器，…Using an EDID Editor/Viewer utility you can view the EDID… 你可以直接看到一个播放设备的EDID数据。…of a display device when directly connected to a source.

  48. Verify AVR Includes its Audio with EDID of Display AV Receiver should combine (add) its audio data with the EDID of the downstream sink device. 在这里你可以看到，重发器当连接到相同的播放设备时，重发器的EDID数据。Here you can see the EDID of the repeater(AVR) device when connected to the same display device. 注意，这时，经过重发器后，音频具有了更多功能。Notice that there are many more audio capabilities. 这个重发器，在这个情况，重发器就是这个AV接收器…The repeater, in this case an Audio Video Receiver has substituted its audio… …已经替换上了自己的音频数据块取代了播放设备的音频数据块。…block for the display’s audio block.

  49. High Definition Content Protection (HDCP)高带宽数字内容保护技术(HDCP) Audio音频 AVMute音频视频静音 Lipsync音频和视频的同步 Video视频方面 Consumer Electronic Control (CEC)消费电子控制

  50. Audio / Video Muting - AVMute Why is AVmute a good practice? To avoid HDCP reauthentication when video timing changes occur. To eliminate adverse video and audio artifacts (e.g. blinking, pops and clicks) during video timing changes or HDCP authentication. How does AVmute work? General Control Packets are sent with AVmute set / clear. What solutions have developers requested to help address potential AVmute interoperability issues? Show AVmute in relation to TMDS clock changes. Show AVmute in relation to encryption enable pulse. Show AVmute in relation to audio sample packet data. Provide timing data as to how many fields before and after a TMDS clock interruption the AVmute set and clear occur. Important when there are cascaded repeaters (high depth count). Avmute是当没有音频视频内容时，让音频和视频静音的简单方式。AVmute is simply a way of muting the audio and video in cases where there is no useful audio or video content. Avmute的好处有几个原因：AVmute is a good practice for a few reasons: 消除不良的视频和音频噪音（如闪烁、砰砰声、咔嚓声等）Primarily to eliminate adverse video and audio artifacts (e.g. blinking, pops and clicks) during video timing changes or HDCP authentication. Avmute是怎么工作的？How does AVmute work? Avmute设置/清除的数据包含在General Control Packets里一起被传输。General Control Packets are sent with AVmute set / clear. The sink device mutes its audio and video. 研发者需要什么解决方法来解决Avmute的互通性问题呢？What solutions have developers requested to help address potential AVmute interoperability issues? 显示当Avmute发生时， TMDS的时序发生的变化。Show AVmute in relation to TMDS clock changes. 显示当Avmute发生时，HDCP解码启动脉冲的情况Show AVmute in relation to encryption enable pulse. 显示当Avmute发生时，音频样本包的数据。Show AVmute in relation to audio sample packet data. 提供时序数据，来显示从Avmute指令设置到TMDS时序变化的时间段内产生了多少field，…Provide timing data as to how many fields before and after a TMDS clock interruption the AVmute set and clear occur. …并显示在TMDS时序变化后到Avmute指令清除之间的时间段内产生了多少fieldThis is important when there are cascaded repeaters (high depth count)…

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