iphone邮箱加密发送

More than a few readers have written in with the same question: why does the quality of videos sent via text message from their iPhones vary so wildly? Read on as we dig into why it has nothing to do with the quality of your iPhone camera and everything to do with what happens after you take the video.

不少读者写了一个相同的问题：为什么通过iPhone短信发送的视频质量如此之大？ 请继续阅读，深入了解为什么它与iPhone相机的质量无关，以及与拍摄视频后发生的一切无关。

Dear How-To Geek,

亲爱的How-To Geek，

The other day I sent a video of my daughter playing at the park to my brother and my parents. Later, my parents said the quality of the video was very low with poor sound and blocky images. I asked my brother about it and he said the video looked great.

前几天，我向哥哥和父母发送了一个关于女儿在公园玩耍的视频。 后来，我的父母说视频质量很差，声音差且图像块状。 我问了我兄弟，他说视频看起来很棒。

Since then I’ve tested out a few other videos to the same end. Half the people I’ve sent them too have said they look great and half the people have said they look pretty blocky and like old camera phone videos. What gives? How can one group get crystal clear video like I copied the video right over to their phone and the other group get something that looks like an old webcam? Help!

从那时起，我已经测试了其他一些视频。 我发送给他们的人中有一半也说他们看起来很棒，一半人说他们看起来很笨拙，就像旧的照相手机视频一样。 是什么赋予了？ 像我将视频直接复制到他们的手机上一样，另一组如何获得清晰的视频，而另一组如何获得类似于旧网络摄像头的内容？ 帮帮我！

Sincerely,

真诚的

Video Puzzled

视频不解

The above letter is just one of the many we’ve gotten recently regarding video quality on the iPhone. People are understandably confused because, say what you will about Apple or the iPhone, the iPhone has a really great camera in it and takes very sharp videos. As such it’s a real curiosity when you send the video to someone and it looks like rubbish.

上面的信件只是我们最近获得的有关iPhone上视频质量的众多信件之一。 人们之所以困惑是因为，比如说您对Apple或iPhone的看法，iPhone的相机非常出色，可以拍摄非常清晰的视频。 因此，当您将视频发送给某人时，这确实是一种好奇，看起来像垃圾。

Why the discrepancy though? Why does one group get a crystal clear video and one group get something that resembles a webcam video from 1995? The reason has nothing to do with limitations of the iPhone’s camera, a glitch in iOS or the Message app, or anything within the control of Apple or your phone and everything to do with the limitations of cellular protocols and the networks they run on.

为什么会有差异？ 为什么一组人获得清晰的视频，而一组人却得到类似于1995年的网络摄像头视频的东西？ 原因与iPhone的摄像头的限制，iOS或Message应用程序中的故障或Apple或您的手机控制范围内的任何事情以及蜂窝协议及其所运行的网络的限制无关。

MMS和蜂窝载波限制 (MMS and Cellular Carrier Limitations)

The video quality killer is a one-two punch administered by the limitations of MMS (Multimedia Messaging Service), the extension of the SMS text messaging protocol that allows us to send photos and video through the cellular network, coupled with aggressive compression applied by the actual cellular providers.

视频质量杀手是由MMS(多媒体消息服务)的局限性管理的一站式服务，这是SMS文本消息协议的扩展，它使我们能够通过蜂窝网络发送照片和视频，以及由移动电话应用的积极压缩。实际的蜂窝电话提供商。

MMS messages are size limited at the carrier level and that size limit ranges from 300KB to around 1200KB (or, 0.3MB to 1.2MB). Typically the high-end of that scale, MMS messages exceeding 1,000KB, are limited to intra-carrier messages (e.g. one Verizon user can send a large MMS message to another Verizon user) but limitations between carriers, inter-carrier communication, is limited to 300-600KB.

MMS消息在运营商级别受到大小限制，并且大小限制范围从300KB到大约1200KB(或0.3MB到1.2MB)。 通常，这种规模的高端(超过1,000KB的MMS消息)仅限于载波内消息(例如，一个Verizon用户可以向另一个Verizon用户发送大型MMS消息)，但是载波之间的限制(载波间通信)受到限制到300-600KB。

Thus by default, regardless of the quality of the camera on your phone, your iPhone will automatically compress any video sent over MMS to another phone (iPhone on your network, Android phone on another network, makes no difference) in order to reduce the very large and high quality original video file to a size that can be managed by the MMS system.

因此，默认情况下，无论手机上相机的质量如何，iPhone都会自动压缩通过彩信发送到另一部手机(网络上的iPhone，另一网络上的Android手机没有影响)的任何视频，以减少大型高质量的原始视频文件，其大小可以由MMS系统管理。

To further compound the issue some carriers even apply additional compression in a bid to reduce overhead on their own network so by the time your video reaches the recipient it may have been compressed not once but multiple times, ultimately completely degrading the quality of the video.

为了进一步解决该问题，一些运营商甚至采取了额外的压缩措施，以减少其自身网络的开销，因此，到您的视频到达接收者时，它可能已经压缩了一次，而是多次压缩，最终完全降低了视频质量。

That explains why the video quality is low for some of your recipients, but what about the people who get high quality video instead? That’s where iMessage comes in. Although in day-to-day use it’s easy to forget your iPhone is set up to use iMessage it’s important to remember that iMessage is beholden to the limitations of SMS/MMS protocols. iMessage is more like a super-charged instant messaging service run over the data network (akin to ICQ, AIM, and Google Hangouts) than it is like the cellular-based messaging protocols it seeks to replace.

这就解释了为什么某些接收者的视频质量低下，但是获得高质量视频的人又如何呢？ 这就是iMessage出现的地方。尽管在日常使用中，很容易忘记将iPhone设置为使用iMessage，但重要的是要记住，iMessage受到SMS / MMS协议的限制。 iMessage更像是一种通过数据网络(类似于ICQ，AIM和Google Hangouts)运行的收费即时消息传递服务，而不是它想要取代的基于蜂窝的消息传递协议。

Because iMessage sends all its content through the data network via the Internet and Apple’s servers it is not restricted in the same fashion. Although there are still limitations to the iMessage file delivery system, the limits (although not officially published) max out at around ~220MB. That’s more than enough to send crystal clear video clips without running into any issues until the videos become quite lengthy.

因为iMessage通过Internet和Apple的服务器通过数据网络发送其所有内容，所以它不受相同方式的限制。 尽管iMessage文件传送系统仍然存在一些限制，但这些限制(尽管尚未正式发布)最大约为220MB。 这样就足以发送清晰的视频剪辑，而不会遇到任何问题，直到视频变得很长为止。

保持发送的视频质量高 (Keeping Sent Video Quality High)

Although the size restrictions of MMS are unavoidable when using the MMS system there are ways to mitigate it when you must use it and step around it completely when you want the highest video quality. Let’s take a look at some tips and tricks for increasing video quality.

尽管在使用MMS系统时不可避免地会受到MMS大小的限制，但是有一些方法可以在必须使用MMS系统时减轻它，并在需要最高视频质量时完全绕开它。 让我们看一下提高视频质量的一些技巧。

积极修剪您的视频 (Aggressively Trim Your Videos)

Each one of us has been guilty of being a lazy videographer at some point. Rather than send a long video where includes you urging your kid to do something cute, or to hop back up on the top of the slide to wave to grandma, trim the video down using the in-phone tools so that just the important part is sent to the recipient.

我们每个人都曾在某个时候成为一名懒惰的摄影师而感到内gui。 与其发送长视频，其中不包括敦促您的孩子做一些可爱的事情，或者跳回幻灯片的顶部以向奶奶挥手，不如使用电话内的工具来修剪视频，以使重要的部分发送给收件人。

This way, regardless of the method you use, you’ll get the highest quality video for the most important part and not waste time or data transferring the fluffy bits.

这样，无论使用哪种方法，对于最重要的部分，您都将获得最高质量的视频，而不会浪费时间或数据传输蓬松的位。

开启iMessage (Turn on iMessage)

Sometimes iMessage gets turned off (like when you change your master account password) and you forget to turn it back on. Ensure that iMessage is enabled on your own phone and then help your friends and family enable it on their phones too.

有时，iMessage会关闭(例如，当您更改主帐户密码时)，而您忘记重新打开它。 确保在您自己的手机上启用了iMessage，然后帮助您的朋友和家人也在他们的手机上启用它。

In the above image you can see where the setting is located, under Settings -> Messages -> iMessage. Note that we highlight the the “Send as SMS” feature too (and recommend you keep it on). If you turn that toggle off then any iMessage you send to a fellow iMessage user will only send through the iMessage network, which is data-connection dependent. If you want to ensure the text always gets through even if iMessage is unavailable then you want that checked.

在上图中，您可以在设置->消息-> iMessage下查看设置的位置。 请注意，我们也突出显示了“发送为SMS”功能(并建议您保持打开状态)。 如果关闭该开关，则发送给其他iMessage用户的任何iMessage都只会通过iMe​​ssage网络发送，该网络取决于数据连接。 如果您要确保即使iMessage不可用，文本也始终可以通过，那么您需要进行检查。

Obviously iMessage only works for Apple-to-Apple product communication but it works awesome (and a surprising number of people don’t even have it on).

显然，iMessage仅适用于Apple到Apple的产品通信，但是它很棒(并且很多人甚至没有使用它)。

给他们发电子邮件 (Email Them)

If iMessage isn’t an option there’s always email. While MMS is limited to anywhere from 0.3-1.2MB file sizes, most email providers allow for file sizes anywhere from 3MB to 25+MB in size. it’s a bit of a stop-gap measure between the spaciousness of the iMessage limits and the restrictions of MMS, but in a pinch it’ll do.

如果不能选择iMessage，则总是有电子邮件。 虽然MMS的文件大小限制为0.3-1.2MB，但大多数电子邮件提供商都允许文件大小为3MB至25 + MB。 在iMessage限制的范围和MMS的限制之间，这是一个权宜之计，但在一定程度上会做到。

Note: The limitations on their email account are as important as the limitations on your email account as restrictions generally apply to both the sending and receiving of attachments. When it doubt error on the side of smaller and aim to keep your email video clip compact.

注意：他们的电子邮件帐户的限制与您的电子邮件帐户的限制一样重要，因为限制通常同时适用于发送和接收附件。 当它怀疑较小的一侧的错误时，力求使您的电子邮件视频剪辑紧凑。

使用文件共享服务 (Use a File Sharing Service)

Ideally, you’re sending a file from one iMessage user to another iMessage user and you’ll never even have to think about file limits or whether or not the file will get compressed into an ugly mess. Working within the limits of the MMS protocol or emailing the file is a huge compromise in quality.

理想情况下，您是将文件从一个iMessage用户发送到另一个iMessage用户，而您甚至不必考虑文件限制或文件是否会压缩成丑陋的混乱。 在MMS协议的范围内工作或通过电子邮件发送文件是质量的巨大折衷。

There is a sort of middle ground, however, you can take when you want to preserve the quality while communicating with a non-Apple user. It requires a little more hoop jumping than just a plain old message but if you want to preserve the large file size and quality you can share the file via one of the many cloud-based file services like Dropbox, One Drive, Google Drive, or the like, as long as the service supports sending a link to a hosted file.

但是，在与非Apple用户交流时要保持质量时可以采取一些中间立场。 与普通的旧消息相比，它需要更多的跳动，但是如果您想保留大文件的大小和质量，则可以通过许多基于云的文件服务(例如Dropbox，One Drive，Google Drive或只要服务支持发送到托管文件的链接。

To that end you take your video, upload it to Dropbox, and then share the link via plain old text message or email with the recipient. That’s not exactly a friction free experience but it does get your large file there sans compression.

为此，您要拍摄视频，将其上传到Dropbox，然后通过旧的短信或电子邮件与收件人共享链接。 这并不是完全没有摩擦的体验，但是可以使您的大文件在没有压缩的情况下到达那里。

In summary, the reason some people get high quality videos and some people don’t is because the high quality content is delivered by the iMessage system and the low quality content is a result of file size restrictions and heavy-handed compression applied to meet the limitations of the MMS protocol. When possible, get your friends using iMessage and, barring that, when you must use MMS send shorter clips or email/cloud-share the files.

总而言之，有人获得高质量视频而有些人没有获得高质量视频的原因，是因为iMessage系统提供了高质量的内容，而低质量的内容是由于文件大小受到限制并采用了繁重的压缩方式来满足要求的， MMS协议的局限性。 尽可能让您的朋友使用iMessage，并且在必须使用MMS的情况下，请发送较短的剪辑或通过电子邮件/云共享文件。

Have a pressing question about your iOS device? Shoot us an email at ask@howtogeek.com and we’ll do our best to answer it.

对您的iOS设备有紧迫的问题吗？ 向我们发送电子邮件至ask@howtogeek.com，我们将尽力答复。

Image credit: Carl Lender.

图片来源： Carl Lender 。

翻译自: https://www.howtogeek.com/228626/htg-explains-why-do-videos-sent-from-my-iphone-vary-so-much-in-quality/

iphone邮箱加密发送