MYDP引爆移动高清视频传输技术争夺战火

移动产业一直没有对可从智能手机传送高清(HD)视频到外部HDTV的介面做出明确抉择。然而，Analogix公司最近发布的SlimPort系列元件──相容于ST所推动的MYDP数字介面──却有可能打破这种微妙平衡。

当谈到HDTV介面时，业界观察家们一致认为，最初由Silicon Image公司所推动的HDMI将会是赢家。然而，在移动世界里，这样的共识却并不适用。对于可从智能手机或平板装置传送高清(HD)视频到外部大尺寸屏幕电视的介面，移动产业一直没有做出明确表态。

Analogix主要开发基于DisplayPort的互连技术，该公司新推出的产品相容于ST所推动的MYDP(移动DisplayPort)。MYDP是一种专为移动市场所设计，旨在减少数字通讯讯号接脚数量的数字移动介面。今年初，ST将MYDP作为DisplayPort标准的一部份，向视频电子标准协会(VESA)提交了一份提案。

ST公司CEO Carlo Bozotti今年五月时曾表示，ST承诺将DisplayPort的采用领域从监视器扩展到移动设备。Bozotti接着表示，DisplayPort将对该公司的未来营收有所助益。

尽管VESA尚未针对MYDP展开评议咨询期(comment period)，但Analogix已经抢先一步，稍早前(9月7日)，该公司发布了自有的SlimPort系列发射器和接收器芯片──它们均使用和DisplayPort相同的基础技术──相容于ST所推动的MYDP数字介面。

此举揭开了MYDP与移动高清连接(MHL)的战 争序幕。

Jon Peddie Research公司总裁Jon Peddie解释道，MYDP介面并不指定连接器类型。“这将使设备制造商有权决定他们想要使用的连接器。”MYDP具有MUX，允许DisplayPort的与USB共用，并能将标准的Micro USB介面同时用于DisplayPort和USB的连接，他表示。

Analogix和ST这两家公司均打算凭借着SlimPort和MYDP与Silicon Image和MHL正面交锋。

三年多前，Silicon Image和其他一些公司开发了MHL，这是一种崭新的移动音频/视频介面标准，可用于将移动电话和其它便携式设备连接到高清电视(HDTV)和显示器。

IHS iSuppli的显示电子暨消费市场首席分析师Randy Lawson指出，“我相信，尽管MHL的起步较慢(该标准2008年才推出市场，但首个正式标准却迟迟未释出，直到去年仅有三星出货了首批产品)，但MHL仍有希望”。他形容HDMI是“实际上的高清显示介面标准”，因为它在HDTV领域无处不在，而且在移动领域(如笔电)中，HDMI传输埠也不断成长。“这似乎强化了MHL未来有充分获得应用机会的观点，”他表示。

Peddie同意这个观点。“MHL拥有一些组织的支持，因此可获得更多工程资源，也或许它背后有更多政治力量。所以，如果必须选择一个胜利者，我会选MHL。”

然而，Peddie也承认DisplayPort已经在PC、笔电、平板装置和监视器等领域获得大量采用。随着DisplayPort的接受度日益提升，“DisplayPort对移动装置连接高清显示装置的支持将成为一种自然的发展过程。”

MHL转HDMI并非已成定局

在此同时，ST和Analogix则是致力于让全世界了解，从MHL到HDMI，要真正落实在移动领域仍然是很遥远的事。他们坚持MYDP和SlimPort仍然有很多时间和机会来让市场接受它们。

Analogix公司行销副总裁Andre Bouwer认为，MYDP会获得移动应用处理器、操作系统和手机的支持。

MYDP会比MHL更具吸引力吗？如果是，那又代表什么意义？

免授权费是首要也是最重要的优势。SlimPort和MYDP都是基于VESA组织的DisplayPort，这是一种自由、开放的标准。

其次，SlimPort和MYDP均可连接到HDMI、VGA以及DisplayPort显示器。这是与MHL的一项最大区别，Analogix的Bouwer说，透过SlimPort(或MYDP)，你可以连接智能手机与一部投影仪来做简报。“目前还没有办法将一台搭载了MHL的电话连接到具备VGA或DisplayPort的装置，如投影机，”他表示。

第三，也是必须注意的重点，是MHL、SlimPort和MYDP都是为了让已经存在于许多手机中的USB介面也能传输视频所建构的。而SlimPort/MYDP和MHL的关键区别在于传送视频串流时的功耗。

举例来说，三星首款搭载MHL的Galaxy S II智能手机，其MHL可运用标准Micro USB介面连接外部HDMI显示设备，如HDTV。MHL能透过手机，将无压缩的1,080P视频和音频内容传送到电视。MHL的优势在于它能为智能手机的电池充电，并同时播放多媒体内容。

下一页：MHL和HDMI是两回事

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MHL和HDMI是两回事

然而，有一件很少被公开提及的事情，就是搭载MHL的移动设备，仅能从同样搭载MHL的外部显示器获得功率。“MHL和HDMI是两回事，”Bouwer强调。迄今东芝是唯一一家公开承诺及计划推出具备MHL功能数字电视的业者。

在缺乏具备MHL的HDTV的今天，一部像Galaxy SII这样的MHL手机，在必须将HD视频串流传送到外部显示设备时，最终可能还是得耗用自己的电池电力。另外，MHL移动设备也能透过MHL- HDMI dongle来连接现有的HDMI电视。不过，出于功耗考量，“仍需要一条独立的电源线，”Bouwer表示。

相较之下，SlimPort立即可用，毋须任何修改即可适用于现有电视，而且不需要不方便的电缆，他表示。

Bouwer举了一个具备DisplayPort输入的例子──戴尔的UltraSharp U2711。SlimPort设备能在显示器上播放视频的同时，也为电池充电。

不过，并非每一款今天的HDTV都具有DisplayPort介面。这不成问题，Bouwer表示。“DisplayPort输入会自然地应用到电视中，取代VGA输入，未来几年内VGA的比重将逐步下降。这种输入介面能够为移动设备提供电源，据DisplayPort的规格显示，约可提供1.5W电源。”

现在，若你连接SlimPort到既有的HDMI HDTV时，会发生什么事？在这种情况下，SlimPort的发射器约消耗100mW功耗，而dongle则几乎不消耗任何功率，Bouwer表示。“这是由于DisplayPort的一部分特性，以及Analogix的功率恢复技术。其功耗小于移动设备的内部显示，因此，你在大屏幕上的播放时间，甚至可以比在移动装置上的播放时间要长。也因此不再需要电力线。”

不过，业界也已经开始开发搭载MHL的数字电视，据一位Silicon Image的发言人表示，该公司正在等待其OEM厂商发布产品。当被问及OEM如何开发采用Silicon Image埠处理器的MHL电视时，这位发言人表示，他们必须“确保数字电视中的韧体包含对MHL技术的支持，而后必须添加一个电压调节器，让数字电视能透过现有连接器来提供电源。”她表示，该公司估计添加电压调节器大约会增加5~10美分的额外费用。

移动应用处理器是否支持DisplayPort？

Analogix的Bouwer表示，所有领先的应用处理器在其设计中都会开始支持，或是将DisplayPort整合到他们的显示器输出介面中。然而，当《EE Times》询问高通(Qualcomm)或NVidia有无此一计划时，他们都拒绝回答。

Bouwer同时强调，移动操作系统供应商也支持DisplayPort。例如，Google已在今年稍早加入DisplayPort组织。“他们的计划是支持具备DisplayPort功能的智能手机和平板装置，因为他们的应用处理器伙伴要求他们这么做。”

不过，目前的手机OEM厂商支持DisplayPort的情况如何？截至目前，仅有三星和HTC的手机搭载MHL。“随着发布基于DisplayPort技术的SlimPort晶片，我们已经看到OEM对SlimPort解决方案展现出高度兴趣，”Bouwer说。“随着DisplayPort透过应用处理器供应商在硬体上进行部署，加上操作系统供应商的支持，未来手机制造商将自然在移动装置上采用DisplayPort解决方案，”他总结道。

MIPI-DSI移动设备的未来？

然而，事情可能没有那么简单。IHS iSuppli的Lawson为MHL反驳道，“用于移动设备的嵌入式显示介面技术MIPI-DSI(数字串列介面)不会轻易改变。”他接着表示，“因此，支持MYDP意味着未来的应用处理器晶片将整合两个独立的高速串列显示介面技术，而且即使如此，在这些设备的DisplayPort输出与HDMI接收器的输入之间仍需要一个主动式dongle。”

事实上，Analogix的首款SlimPort产品已开始出样，它具有一个MIPI输入和DisplayPort输出，Bouwer表示。“MIPI-DSI将持续用于中小型手机的内部显示介面。”但他指出，“未来平板装置需要的更高清度(如1,920 x 1,200或更高)，将需要具备更高频宽的DisplayPort。为抢占平板装置市场，未来应用处理器厂商将会添加eDP (嵌入式DisplayPort)。而DisplayPort和MIPI将分别存在于大、小屏幕之中。”

点击参考原文：Analogix fires an opening salvo in MYDP vs. MHL battle

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Analogix fires an opening salvo in MYDP vs. MHL battle

Junko Yoshida

When it comes to the HDTV interface, industry watchers agree that HDMI, originally developed by Silicon Image, is the hands-down winner.

But in the mobile world, no such consensus applies. The mobile industry hasn’t indicated its interface preference for streaming HD video from a smartphone or a tablet to an external large-screen TV.

Analogix Semiconductor, Inc. (Santa Clara), focused on DisplayPort-based interconnect technologies, is hoping to tip this uncertain balance, by joining STMicroelectronics’ effort to push MYDP (Mobility DisplayPort).

MYDP is a mobile digital interface designed to reduce the number of communication signal pins for the mobile market. Earlier this year, ST, billing it as a companion to the DisplayPort standard, submitted an MYDP proposal to the Video Electronics Standards Association (VESA).

ST and ST-Ericsson are now both behind MYDP.

Carlo Bozotti, ST’s CEO, expressed in May ST’s commitment to extend the adoption of DisplayPort beyond monitors to mobile devices. Bozotti then said: “DisplayPort can contribute a lot to our top-line evolution.”

Although VESA’s comment period hasn’t started for MYDP, Analogix is jumping the gun and announcing Wednesday (Sept. 7th) that the company’s own SlimPort family of transmitter and receiver chips – which use the same underlying technology as DisplayPort – is compatible with the ST-promoted MYDP digital interface.

Consider this move an opening salvo in the MYDP vs. Mobile High-Definition Link (MHL) battle.

As Jon Peddie, president of Jon Peddie Research, explained, the MYDP interface doesn’t specify the connector type. “That makes it up to the device makers to decide whatever connector they want to use.” MYDP features a MUX that allows the DisplayPort signal to share signaling with USB, allowing the standard Micro USB port to be used for both DisplayPort and USB connectivity, he added.

Both Analogix and ST, armed with SlimPort and MYDP, intend to go head-to-head against Silicon Image and MHL.

More than three years ago, Silicon Image and a consortium of companies developed MHL, a new mobile audio/video interface standard for connecting mobile phones and other portable devices to high-definition televisions (HDTVs) and displays.

MYDP is ‘a rogue’ interface

Industry observers and analysts are hedging their bets on MYDP – for now – over concerns that it’s just a re-invention of the MHL wheel.

Randy Lawson, IHS iSuppli, principal analyst for display electronics and consumer market research, noted, “I do believe that MHL has much promise, despite a slow start (MHL was announced in 2008; but the first official standard was not released until last year and first products only coming out now from Samsung).” He described HDMI “the de-facto standard for HD display interface,” because its ubiquitous status in HDTVs, and on-going growth of HDMI transmission ports into the mobile space (like laptops). “That would seem to bolster a view that MHL has ample opportunity for future design-ins,” he added.

Peddie agreed. “MHL has some consortium backing and therefore has more brain power and maybe political power behind it. So if I had to pick a winner it would be MHL.”

Peddie, however, also acknowledged the strong adoption rate DisplayPort has achieved in the PC, notebook, tablet and monitor spaces. As acceptance of DisplayPort grows, “it would be a natural progression of DisplayPort to support HD display connectivity from mobile devices.”

The two analysts agree on this: MYDP and MHL are trying to accomplish the same thing. Lawson said, “I am not aware of any significant trend to support DisplayPort in mobile devices [at this point]. And I would say that the capability added would seem redundant anyway.” Calling MYDP “a rogue,” Peddie said that it threatens to take the industry “back to the future of a different connector on every system trying to do the same thing.”

‘MHL to HDMI is not a done deal’

Meanwhile, STMicroelectronics and Analogix are on a mission to let the whole world know that MHL to HDMI is far from a done deal in the mobile world. They insist that MYDP and SlimPort still have a plenty of time and opportunity to achieve broader acceptance.

Andre Bouwer, vice president of marketing for Analogix, believes MYDP will win support in mobile application processors, operating systems and mobile handsets. Bouwer, while declining to name names, hinted that his company has stirred interest in its forthcoming Slimport products from handset OEMs and apps processor companies.

What exactly would make MYDP more attractive than MHL, then?

Being royalty-free is the first and foremost advantage. SlimPort and MYDP are both based on DisplayPort, a standard owned by VESA and conceived to be a free, open standard.

Second, SlimPort and MYDP can connect to HDMI, VGA and DisplayPort displays. This is an important distinction from MHL, in the view of Analogix’s Bouwer, because with SlimPort (or MYDP), professionals can deliver presentations by connecting a smart phone to a projector. “There is no way to connect a phone with MHL to VGA or DisplayPort display devices like projectors,” he added.

Third, it’s important to note that MHL, SlimPort and MYDP were all created to make the USB connector – already present to power the phone – also transfer video. The key difference between SlimPort/MYDP and MHL, lies in power consumption when streaming video.

Take an example of Samsung’s Galaxy S II smartphone, the first MHL-enabled handset. The Galaxy S II’s standard Micro USB port can be used with an MHL connector for HDMI connection to an external display such as an HDTV set. MHL lets the handset send uncompressed 1080P video and audio to the TV. MHL’s advantage is that it allows the smartphone’s battery to charge while playing back multimedia content.

‘MHL and HDMI are not the same thing’

What may be less openly publicized, though, is that the MHL-enabled mobile device can only draw power from MHL-enabled external displays. “MHL and HDMI are not the same thing,” stressed Bouwer. To date, Toshiba is the only company openly committed with a plan to launching MHL-enabled digital TVs.

In the absence of MHL-enabled HDTV today [HDTV sets on the market today do not support MHL], a smartphone like Galaxy SII featuring MHL could end up eating its own mobile device’s battery when streaming HD video to external displays. Alternatively, MHL-enabled mobile devices can connect to legacy HDMI TVs by using a MHL-to-HDMI dongle. However, because of power consumption issues, “a separate power cable is required,” noted Bouwer.

In contrast, SlimPort can be implemented immediately, driving legacy TVs without modifications and without the need for inconvenient power cables, he added.

Bouwer offered the example of displays with DisplayPort input, like the Dell Ultrasharp U2711. SlimPort devices can charge batteries while playing video on the display.

But not every HDTV today has a DisplayPort. No problem, says Bouwer. “DisplayPort inputs will naturally be added to TVs to replace VGA inputs as VGA declines in the coming years. This input can provide power to the mobile device -- 1.5 watts (W) according to the DisplayPort specifications.”

OK, so what happens if you connect SlimPort to a legacy HDMI-equipped HDTV? In this scenario, SlimPort consumes around 100 milliwatts (mW) in the SlimPort transmitter and around zero milliwatts (mW) in the dongle, according to Bouwer. “This is due in part to the nature of DisplayPort as well as Analogix power recovery technology. The power consumption is less than the internal display of the mobile device, so you can play video longer on the big screen than you can on the internal display. Therefore, no power cables are required.”

To be absolutely fair to Silicon Image, though, MHL-enabled DTVs have been in development, and the company is waiting for its OEMs to announce them, according to a Silicon Image spokesperson. Asked what it would take for OEMs who designed in Silicon Image’s port processors to make their TV sets MHL-capable, she said they must “ensure [that] the firmware in the DTV includes support for MHL technology, and then add a voltage regulator to enable the DTV to provide power over the existing connector.” She noted, “Our estimate is that the addition of the voltage regulator is 5 – 10 cents additional cost.”

Do mobile apps processors support DisplayPort?

Building the case for MYDP, Analogix’ Bouwer said, “All leading apps processors in the world are either designing in, or in the process of integrating DisplayPort in to their display output interfaces.” However, when EE Times asked Qualcomm and NVidia about such a plan, they both declined to answer.

Bouwer also stressed DisplayPort support among mobile OS suppliers. Google, for example, have joined a DisplayPort consortium earlier this year. “Their plan is to support the smartPhone and tablet space with DisplayPort driver functionality as they were requested to do so by their apps processor partners.”

But is there support for DisplayPort among handset OEMs vendors? So far, the Samsung and HTC handsets are the only devices designed with MHL. “With the introduction of SlimPort chipsets from Analogix (based on DisplayPort Technology) earlier this year, we have seen OEMS take significant interest in the elegance of the SlimPort solution,” said Bouwer. “With DisplayPort deployment in the hardware by apps processor providers and software by the OS providers, it is natural for handset makers to adopt the DisplayPort solution on the mobile devices,” he concluded.

What about MIPI-DSI for mobile devices?

But things may not be that simple. IHS iSuppli’s Lawson, arguing the case for MHL, stressed, “The embedded display interface technology of MIPI-DSI (digital serial interface) for mobile devices is not expected to change.” He added, “So support for MYDP would make two separate high-speed serial display interface technologies required to be integrated in future apps processor chips, and even then would still require an active dongle between the DisplayPort output of such a device and the HDMI receiver input.”

Indeed, Analogix’s first SlimPort products, sampling now, have a MIPI input and DisplayPort output, Bouwer responded. “MIPI-DSI will continue to be the internal display interface for small and medium sized mobile phones.” But he added, “The higher resolutions used in planned tablet designs (e.g. 1920x1200 or higher) require the higher bandwidth capability of DisplayPort. Application processor makers will add eDP [embedded DisplayPort] in order to compete for tablet designs. DisplayPort and MIPI will coexist for large and small screens respectively.”