Google Chromecast是一种设备，您可以将其插入电视的HDMI端口，并用于流式传输来自(HDMI)Netflix、YouTube甚至Amazon Prime Video等各种流媒体服务的内容。
虽然设置看起来很简单，但许多人误解了Google Chromecast的实际工作原理。您可能认为您是直接从您投射视频流的设备流式传输内容，但事实并非如此。
事实上，有多种方法可以将内容流式传输到Chromecast以及与之配合使用的各种设备和服务。本文将介绍Google Chromecast的工作原理，并揭开这款强大的流媒体设备背后的技术之谜。
Google Chromecast 里面有什么？(What’s Inside a Google Chromecast?)
在我们了解适用于Google Chromecast的服务以及您如何控制它之前，了解Google Chromecast技术的工作原理非常重要。
Chromecast设备插入电视的HDMI端口(HDMI)。如果您有 4K 或使用高动态范围(Range)视频 ( HDR )，那么您可能需要购买 Chromecast Ultra(Chromecast Ultra)。Ultra支持这些，并且具有支持如此高速率数据传输的以太网适配器。(Ethernet)
然而，对于大多数用户来说，价格仅为超值一半（35 美元） 的普通Chromecast就足够了。(Chromecast)
Chromecast内部硬件包括以下所有内容：
- HDMI 输出连接器
- 用于供电的微型 USB 端口
- 512 MB SDRAM（第二代有 4 GB SDRAM）
- 2 GB 闪存
- 双频 Wi-Fi 802.11(Dual-band Wi-Fi 802.11) b/g/n/ac 适配器
- NFC 和 FM 接收器
该设备将随附一根USB数据线，您可以使用该数据线将Chromecast插入任何标准USB 2.0 端口(USB 2.0 port)为其供电。许多现代电视机包括一台。
Google Chromecast 是如何工作的？(How Does Google Chromecast Work?)
那么，当您将内容投射到Chromecast设备时，这一切是如何工作的呢？
Google在(Google)DIAL Service Discovery协议之上构建了其屏幕共享技术。他们还提供Google Cast 软件开发工具包(Google Cast Software Development Kits)( SDK ) 和应用程序编程接口(Application Programming Interfaces)( API )，供第三方公司开发支持Chromecast的应用程序。
DIAL协议只是Netflix和YouTube开发的用于在同一网络上发现和启动应用程序的技术。SDK(SDKs)和API(APIs)是程序员可以用来将自己的应用程序与Chromecast技术集成的工具。
客户端应用程序和设备向Chromecast DIAL服务器发送HTTP请求。Chromecast设备有自己的Chrome浏览(Chrome)器版本。它使用它来响应HTTP请求并从 Web 检索内容。
许多人错误地认为他们的设备正在从互联网流式传输内容，并将该数据流“发送”到Chromecast以在电视上显示。事实并非如此。能够投射的手机和笔记本电脑等设备仅充当Chromecast的“遥控器” 。
这意味着当您打开YouTube视频并选择Chromecast图标时，会发生以下事件。
- 您的设备向Chromecast(Chromecast)发送HTTP请求，告诉它您要流式传输的内容的URL 。
- Chromecast使用自己的浏览器访问互联网并检索该内容。
- Chromecast将开始流式传输内容。您的设备仍然可以停止、启动、前后移动或调节音量。但是，所有内容流都是直接从互联网通过Chromecast设备传输到电视的。
您可以通过Chromecast启动视频然后关闭手机或笔记本电脑来查看此操作。无论如何，Chromecast将继续流式传输视频。
如何设置 Chromecast(How To Set Up a Chromecast)
由于Chromecast设备会直接为您从 Internet 检索内容，因此您最初需要使用有效的 Wi-Fi 网络登录凭据对其进行设置。该网络还需要具有开放的互联网访问权限。这就是Chromecast设备可能无法在公司或酒店网络上运行的原因，这需要二级浏览器登录凭据才能访问互联网。
要设置新的Chromecast，您需要在移动设备上 安装 Google Home 应用。(install the Google Home app)
安装应用程序后，请按照以下步骤进行设置。
- 将Chromecast(Chromecast)的HDMI输出电缆插入电视的HDMI端口。
- 确保(Make)您的电视已切换到Chromecast插入的正确HDMI输入。选择正确的HDMI源后，您会看到Chromecast显示。(Chromecast)
- 在您的移动设备上打开Google Home应用。
- 在应用程序的左上角，选择+图标。选择设置设备(Set up device)，然后设置新设备(Set up new devices)。
- 该应用程序将引导您完成设置Chromecast所需的步骤。这将包括选择您的 Wi-Fi 网络并输入正确的网络密码。
一旦您的 Chromecast 设置好并准备好从您的移动设备或笔记本电脑接收命令，就可以通过多种方式流式传输内容。
如何投射到您的 Chromecast(How To Cast To Your Chromecast)
根据您要投射的内容，有很多方法可以做到这一点。以下是您可以使用的几个选项。
- 通过投射浏览器选项卡来显示您在浏览器上看到的内容
- 从YouTube(YouTube)等支持 Chromecast 的网站投射
- 从移动设备上支持 Chromecast 的(Chromecast-enabled)应用投射
投射浏览器标签(Cast a Browser Tab)
从浏览器投射是将内容投射到Chromecast的最简单方法之一。
只需选择个人资料图片旁边右上角的三个点，然后从下拉菜单中选择Cast… 。
这将弹出一个窗口，您可以在其中选择要投射到的设备（在所有连接到您的Google Home的设备中）。(Google Home)
选择连接Chromecast的电视。这将立即在电视上显示您的浏览器。
当您滚动或单击新网页时，电视将实时显示您的所有活动。
请记住，如果您希望从网站流式传输视频，这不是最好的方法。理想情况下，您应该选择以投射(Cast)按钮形式提供投射功能的网站（如YouTube或Netflix ） （见下文）。
如果您确实尝试使用浏览器投射功能显示视频，则质量会非常低，或者根本无法使用。对于支持 Chromecast的YouTube或其他网站，它们会自动恢复为Cast功能。
从支持 Chromecast 的网站投射(Cast From Chromecast-Enabled Website)
通过Chromecast(Chromecast)流式传输视频内容的最佳方式是选择支持 Chromecast 的内容站点(Chromecast)。您可以在Google 的 Chromecast 应用和合作伙伴页面上查看启用(Google’s Chromecast Apps & Partners page)Chromecast的提供商的完整列表。
从这些网站启动内容非常容易。您通常可以在视频播放器本身上找到Cast图标。例如，在 YouTube 上(on YouTube)，启动视频后，只需在视频右下角寻找Cast图标。(Cast)
您会看到网络上Chromecast设备的弹出列表，类似于投射浏览器标签时的情况。
只需选择您要从中流式传输视频的Chromecast，视频就会从Chromecast设备播放到您的电视。
另一个支持Chromecast的好网站是Spotify Web Player。当您从Spotify网站播放音乐时，您可以选择窗口底部的设备图标。如果在您的网络上检测到Chromecast设备，这将启动一个弹出窗口，您将在其中看到Google Cast 。
选择Google Cast后，您会看到通常的设备选择弹出窗口，您可以在其中选择要收听音乐的Chromecast电视。(Chromecast)
如果您的电视连接了一个不错的音响系统并且想利用它来听音乐，那么投射音乐非常棒。
您甚至可以使用某些支持 Chromecast 的 PC 应用程序（如 VLC）将视频启动到您的(PC apps that are Chromecast-enabled, like VLC)Chromecast。
从支持 Chromecast 的应用投射(Cast From Chromecast-Enabled Apps)
使用Chromecast最方便的方法是通过手机控制它。无需启动笔记本电脑或计算机。只需(Just)启动任何支持Chromecast的应用程序，您就可以直接从手机开始投射。
Amazon Prime Video应用就是一个很好的例子。多年来，亚马逊(Amazon)拒绝启用与Chromecast设备的兼容性。最近，当亚马逊(Amazon)推出支持 Chromecast 的(Chromecast-enabled)Prime Video应用时，这种情况发生了变化。
现在，当您从Prime Video应用观看剧集或观看电影时，您会在屏幕的右下角看到一个半透明的Cast图标。(Cast)
只需点击该图标并选择您网络上的Chromecast设备，即可在您的电视上观看该Amazon Prime视频。
YouTube应用程序（包括YouTube TV）一直支持Chromecast。您会在屏幕右上角找到Chromecast图标。(Chromecast)
您还可以使用Spotify应用或Google 音乐(Google Music)应用从手机投射音乐。在Google Music中，Cast图标位于窗口的右上角。
在几乎所有情况下，如果音乐或视频应用启用了 Chromecast，并且您在家庭网络中检测到(Chromecast)Chromecast设备，那么当您启动视频或播放音乐时，您会看到此Cast图标。(Cast)
当然，如果您是不喜欢使用Google产品的人之一，可以使用很多Google Chromecast 替代品(Google Chromecast alternatives)。
HDG Explains : How Does Google Chromecast Work?
Goоgle Chromecast is a devісe you can plug into the HDMI port оf your teleνision and use to stream content from a νariety оf ѕtreaming servіces like Netflix, YouTube, and even Amazon Prime Video.
While the setup may seem simple, many people misunderstand how a Google Chromecast actually works. You may think you’re streaming content directly from the device you cast the video stream from, but this isn’t true.
In fact, there are a variety of ways to stream content to a Chromecast, and a wide range of devices and services that work with it. This article will describe how Google Chromecast works and remove the mystery about the technology behind this powerful streaming device.
What’s Inside a Google Chromecast?
Before we get to the services that work with Google Chromecast and how you control it, it’s important to understand how the Google Chromecast technology works.
The Chromecast device plugs into the HDMI port of your television. If you have a 4K or use High-Dynamic Range video (HDR), then you may want to invest in the Chromecast Ultra. Ultra supports these and has an Ethernet adapter that supports such a high-rate of data transfer.
However for most users, the regular Chromecast priced at half the ultra ($35) is sufficient.
Chromecast internal hardware includes all of the following:
- HDMI output connector
- micro-USB port for power
- 512 MB SDRAM (2nd generation has 4 GB SDRAM)
- 2 GB flash memory
- Dual-band Wi-Fi 802.11 b/g/n/ac adapter
- NFC and FM receivers
The device will come with a USB cable that you can use to plug the Chromecast into any standard USB 2.0 port to power it. Many modern TV sets include one.
How Does Google Chromecast Work?
So how does it all work when you cast something to your Chromecast device?
Google built its screen sharing technology on top of the DIAL Service Discovery protocol. They also offer a Google Cast Software Development Kits (SDK) and Application Programming Interfaces (API) for third-party companies to develop Chromecast capable applications.
DIAL protocol is just a technology developed by Netflix and YouTube to discover and launch applications on the same network. SDKs and APIs are tools that programmers can use to integrate their own applications with Chromecast technology.
Client applications and devices send HTTP requests to the Chromecast DIAL server. The Chromecast device has its own version of the Chrome browser. It uses this to respond to HTTP requests and retrieve the content from the web.
Many people mistakenly believe that their device is streaming the content from the internet, and “sending” that data stream to the Chromecast to display on the TV. This isn’t the case. Devices like mobile phones and laptops that are capable of casting only act as a “remote control” for the Chromecast.
This means when you open a YouTube video and select the Chromecast icon, the following events take place.
- Your device sends an HTTP request to the Chromecast, telling it the URL of the content you want to stream.
- The Chromecast uses its own browser to reach out to the internet and retrieve that content.
- The Chromecast will start streaming the content. Your device still has the ability to stop, start, move back or forward, or adjust the volume. However all content streaming is happening directly from the internet through the Chromecast device, and to the TV.
You can see this in action by launching a video through your Chromecast and then turning off your phone or laptop. The Chromecast will continue streaming the video, regardless.
How To Set Up a Chromecast
Since the Chromecast device retrieves content directly from the internet for you, you initially need to set it up with valid login credentials for your Wi-Fi network. That network also needs to have open internet access. This is why a Chromecast device may not work on a corporate or hotel network, which requires a second level of browser login credentials to access the internet.
To set up your new Chromecast, you need to install the Google Home app on your mobile device.
Once you’ve installed the app, follow these steps to get set up.
- Plug the HDMI output cable from your Chromecast into the HDMI port on your TV.
- Make sure your TV is switched to the correct HDMI input your Chromecast is plugged into. You’ll see the Chromecast display when you select the correct HDMI source.
- Open the Google Home app on your mobile device.
- At the top left of the app, select the + icon. Select Set up device, and then Set up new devices.
- The app will walk you through the required steps to set up the Chromecast. This will include choosing your Wi-Fi network and typing in the correct network passcode.
Once your Chromecast is set up and ready to receive commands from your mobile device or laptop, there are dozens of ways to stream content.
How To Cast To Your Chromecast
Depending on what you want to cast, there are many ways to do it. Here are a few options you have available.
- Display what you see on your browser by casting a browser tab
- Cast from a Chromecast-enabled website like YouTube
- Cast from Chromecast-enabled apps on your mobile device
Cast a Browser Tab
Casting from your browser is one of the easiest ways to cast content to a Chromecast.
Just select the three dots on the upper right next to your profile image, and select Cast… from the dropdown menu.
This will pop up a window where you can select which device (among all that are connected to your Google Home) you want to cast to.
Select the TV where your Chromecast is connected. This will immediately display your browser on the television.
As you scroll or click to new web pages, the television will show all of your activities live.
Keep in mind that this isn’t the best approach to use if you’re hoping to stream video from a website. Ideally, you should choose sites (like YouTube or Netflix) that offer casting functionality in the form of a Cast button (see below).
If you do try to display video using the browser cast feature, the quality will be very low or it won’t work at all. And in the case of YouTube or other sites that are Chromecast-enabled, they’ll revert to the Cast functionality automatically.
Cast From Chromecast-Enabled Website
The best way to stream video content through your Chromecast is by selecting content sites that are Chromecast enabled. You can see the entire list of Chromecast enabled providers on Google’s Chromecast Apps & Partners page.
Launching content from these websites is very easy. You can usually find the Cast icon on the video player itself. For example, on YouTube, once you launch the video just look for the Cast icon at the lower right corner of the video.
You’ll see a popup list of Chromecast devices on your network, similar to when you cast browser tabs.
Just select the Chromecast you want to stream the video from and the video will play from the Chromecast device to your TV.
Another good Chromecast-enabled site is the Spotify Web Player. When you’re playing music from the Spotify website, you can select the devices icon at the bottom of the window. This will launch a pop-up where you’ll see Google Cast if there are Chromecast devices detected on your network.
Once you select Google Cast, you’ll see the usual device selection pop-up window where you can select the Chromecast TV you want to listen to music on.
Casting music is great if you have a nice sound system connected to your TV and would like to take advantage of it to listen to music.
You can even launch video to your Chromecast using certain PC apps that are Chromecast-enabled, like VLC.
Cast From Chromecast-Enabled Apps
The most convenient way to use a Chromecast is controlling it from your mobile phone. No need to start up your laptop or computer. Just launch any Chromecast-enabled app and you can start casting right from your phone.
One excellent example of this is the Amazon Prime Video app. For years, Amazon refused to enable compatibility with Chromecast devices. This changed recently when Amazon made its Prime Video app Chromecast-enabled.
Now, when you’re viewing episodes or watching a movie from the Prime Video app, you’ll see a semi-transparent Cast icon at the lower right corner of the screen.
Just tap the icon and select the Chromecast device on your network to watch that Amazon Prime video on your TV.
The YouTube apps (including YouTube TV) have always been Chromecast-enabled. You’ll find the Chromecast icon at the upper right corner of the screen.
You can also cast music from your phone using the Spotify app or the Google Music app. In Google Music, the Cast icon is located at the upper right corner of the window.
In nearly all cases, if a music or video app is Chromecast-enabled and you have a Chromecast device detected on your home network, you’ll see this Cast icon appear when you launch a video or play music.
Of course, if you’re one of those people who don’t like using Google products, there are plenty of Google Chromecast alternatives available.
