Always On the Road

工作需要，

然而廣播器材的文章不多，中文資料更少，

順手口語化做起翻譯，練習英文順便長知識！

（資料來源：http://mankinmedia.com/2016/08/what-is-a-me/ ）

 

What is an M/E
何謂M/E?

So you’re thinking of buying a video switcher, but you don’t know what to buy.
你正想著買台導播機，卻不知道該怎麼選購

Maybe you’re looking through all the features and you don’t really know what all the letters and numbers mean. One big question that commonly arises is: What is an M/E? What does it do for me? Why do I care?

也許你正在硬體功能裡面翻騰，而且真的不知道那些名詞與數字代表什麼意思。有個重要的問題常常提起：何謂M/E? 它能做什麼？我為何要注意這功能？

 

An M/E (sometimes referred to as an ME or MLE depending on manufacturer) is a Mix Effect. All the functions that the switcher performs define what that Mix Effect does.

一個M/E(有時候被稱做一個ME或是MLE，依據製造品牌)是一種混合效果。所有導播機表現的功能定義了何謂混合效果

 

So before we get to the M/E, we should talk about what an M/E isn’t. If you have a punch switch that mechanically selects between sources, and your image on the screen loses sync for a second, that is not a Mix Effect! That would be referred to as a punch switch, bang box, contact closure,pushbutton, bud box, SPST, dead man switch, panic button, etc.

 

所以在我們講到M/E之前，我們應該談論什麼不是M/E。如果你有按壓式開關可以機械式選擇來源，在螢幕上的影像失去同步高達一秒，這就不能稱作混合效果！那只能算是按壓切換，或是bang box, contact closure, push button, bud box, SPST, dead mean switch, panic button等等 

 

M/E是用在專業的導播機上，並且包括了crosspoint，轉場旳時候可以用單cut及真正的混合與wipe，有T bar還有去背機等等。接下來讓我們繼續介紹：

A Mix Effect is used on professional switchers and consists of the following: a crosspoint, a transition area with cuts and a true mix or wipe, a T-Bar, keyer and special outputs. Let’s break each of those down.

Crosspoint

M/E上所指涉的crosspoint是兩排按鈕皆是影像輸入。Crosspoint多半都是一排在是Program（播放出去的現場轉播）另外一排則是Preview（你正預覽的檔案，是接下來要被播放出去的畫面）

A crosspoint on an M/E refers to the two rows of buttons that have your video inputs on them. The Crosspoint is usually laid out with one row on top of the other- one row being Program (fiie: ‘live on the air’) and the other being Preview (fiie: what you are ‘previewing’ to go to air next).

在crosspoint的按鈕數字多半都是表示導播機的影像輸入數字。因此如果你有兩排、共八個按鈕，你擁有的也許就是八個輸入的導播機

The number of buttons on the crosspoint traditionally is the number of inputs you have on the switcher. So if you have two rows of buttons with eight buttons each, then you probably have an eight input switcher.

在crosspoint上面按鈕的數字以往都是對應導播機影像輸入的數字。所以如果你有兩排按鈕，各有八個按鈕，那麼你擁有的可能是一台有八個影像輸入的導播機。

However this isn’t always true. Due to space constraints, some manufacturers have created ‘Shift’ buttons to allow for more physical inputs to be on the switcher chassis than there are physical buttons. By using the Shift button you are allowed to see twice as many sources on a second bank of shifted inputs.

然而這不是永遠的通則。根據空間的排列，有些製造商已經做出"Shift"按鈕在導播機機架上提供給更多實際上的影像輸入來源，而不是做出實際上的按鈕。利用"Shift"按鈕，可以看到兩倍，也就是改變到第二群組的影像來源。

On switchers with an M/E, the Preview row is always on the bottom, and the Program row is always above it. This allows for Technical Directors to comfortably push buttons on the bottom row of an M/E any time, knowing that they are only affecting the Preview bus.

有M/E的導播機上，預覽(Preview)排總是在下面，而主畫面(Program)排總是在預覽排的上面。這些是讓技術人員可以輕鬆按下下排按鈕，並且知道他們都是在預覽排上先試做效果。

(↑這一點我有點懷疑，參考其他家的產品，並沒有這回事)

Transition Area

The transition area is the next aspect of the Mix Effect. Program and Preview are selected by the operator in the crosspoint area and then taken to air by the transition area. The transitions are the ‘Take’ button, which is a cut between Program and Preview. You can use the T-Bar to dissolve between Program and Preview. The ‘Auto-Trans’ button will automatically dissolve between Program and Preview at a pre-defined transition rate (like 15 frames).

轉場特效的地方是ME的另外一個面向。主畫面(Program)跟預覽(Preview)是操作者在影像交叉區所選擇的影像，並且使用轉場功能播送出去。轉場就是"Take"按鈕，也就是主畫面與預覽之間的直接切換（註：台灣喜歡說單cut，中國人說硬切）你可以使用T-Bar溶接(disssolve)主畫面與預覽畫面。"Auto-Trans"按鈕可以依照預設轉場速度(像是15格)自動溶接。

Beware of imitations! The hallmarks of a true M/E will be a robust T-Bar, not some cheap slider. The T-Bar will dissolve between the Program bus and the Preview bus.

請注意其他仿效的器材，真正的M/E有個很明顯的特徵，就是有個堅固耐用的T-Bar, 而不是便宜的推軌(slider)。T-Bar可以溶接主畫面以及預覽畫面。

A-B Switchers

There are some switchers out there that allow the T-Bar To dissolve between the top row and the bottom row, and then back again. These are known as A-B switchers. A-B SWITCHERS ARE NOT MIX EFFECTS!

有些導播機可以讓T-Bar溶接上排按鈕以及下排按鈕的影像。接著回復。這就是所謂的A-B切換機(A-B Switcher)。而A-B切換機並不是混合效果(mix effects)!

In A-B switchers, the Program feed flip-flops between the top row of crosspoints and the bottom row of crosspoints. This means that the Technical Director is constantly pushing buttons on both rows of buttons. When you begin, Program is on the top row (or A-row), then after the flip-flop transition, Program is on the bottom row or B-row. This means that the TD is pushing buttons for Preview on both rows. I promise you with A-B switchers there is bound to be an “oops” during your show- at least twice.

在A-B切換機上，主畫面的來源是在上排以及下排之間交錯。這表示TD(Technical Director)是不斷在按兩排按鈕。當你開始導播工作時，主畫面在上排（或是A排），接著在轉場過後，主畫面就會變成底排或是B排，這表示TD按下按鈕，讓預覽展示在雙排上。我保證你在使用A-B切換機的時候，在現場至少會有兩次 "Oops" 的驚呼。

Down Stream Keyer

The next section of the Mix Effect is the down-stream keyer section. In the signal path the keyer occurs after, or ‘down-stream’ of the transition area. The keyer is what allows you to overlay (or superimpose) graphics or video elements on top of the background layer of video.

Down Stream Keyer (DSK)

接下來關於混合效果的是Down Stream Keyer。在訊號路徑上，這個keyer是最後發生的，或者是在轉場區域的下層影像匯流。這個keyer是讓你可以覆蓋(或是強調)圖像或是背景影像之上，最上層的影像元素。

Chroma-Key

Chroma Key (色相去背)

There are several Different types of keyed effects. A chroma-key replaces one predefined color with video. This is what your local TV station does with the weatherperson. They stand in front of a blue or green screen that is then ‘keyed-out’ and replaced with video; for example a map of your state.

有好幾種不同類型的去背效果。Chroma key是在影像中，取代掉某個被指定的顏色。這就是在地方電視台天氣預報的做法。氣象主播站在一塊綠色或是藍色幕前，接著藍色或綠色被去背，再用影像取代。譬如是用你位在的州郡地圖

Alpha-Key

An alpha-key is a special key that requires an alpha channel signal. This requires a device with a special video card that has the ‘fill’ information that you want to put on the screen as well as the ‘alpha’ information that you want to cut out of the screen.

An alpha key is pretty standard with broadcast graphics machines, and provides a very clean signal. Even now some off-the-shelf graphics programs are partnering with AJA or BlackMagic video cards, and generating alpha information that can then be used by professional switchers to alpha-key.

 

Alpha Key

 

Alpha Key是一種特別為了帶有Alpha Channel訊號而生的去背方式。這需要一張具有fill(填入)訊號的影像卡以填入你要放進螢幕裡面的訊號，也像是alpha訊號是你要從螢幕去除的部分。

Alpha Key是屬於廣電影像的標準機器，提供了純淨的訊號來源。即使一些圖像　

Linear-Key

A linear-key, also called a luma-key or self-key, is where the switcher can overlay a graphic image on top of video without an alpha channel, just by using the difference of the bright and dark information of the graphic. This is where you have a graphic source like PowerPoint that you want to use as your lower-third graphic maker. PowerPoint does not have an alpha channel, so by using a linear-key you can create white text on a black background and then the switcher can key out the black background and superimpose the white text on top of the video.

This works relatively well as long as you can control your graphic to do things like drop shadows. Superfine elements tend to get lost on linear keys.

Outputs

The final feature of a Mix Effect are outputs. This may sound basic, but low-end switchers do not have the outputs that are required for demanding shows. All legitimate video switchers should have a Program output (the composited video image of the crosspoint with the keyers superimposed), a Preview output (the video image of what is selected on the Preview bus) and a Clean Feed (the Program output, but without any downstream keyers being shown).

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So that’s it-the basic functions of a Mix Effect. Now you get to determine what features you need for your show- how many M/Es, how many keyers, how many crosspoints, how many inputs or outputs you need, etc. We’d love to help with all these determinations! Just shoot us a line anytime.