Deep Dive: Working with Open Captions (Subtitles)
by Reinhard Wegner
posted on 07-26-2016
For Premiere Pro CC 2015.3, we introduced a new workflow for Open Captions, also known as subtitles. The main differences between Open Captions and Closed Captions are:
– Open Captions are always visible in the Program and Source Monitor, because they’re treated like a normal video layer and will be “burned in” to the video on export. Closed Captions are encoded into the file and decoded by the display device during playback.
– Open Captions allow nearly unlimited selection of font family, size and color, along with free positioning over the video image. Closed Captions offer limited font, color and position choices, aligned to a fixed grid.
– Open Captions can only be burned into the video image during export, and cannot be stored in separate sidecar files or embedded into video like Closed Captions.
You can create Open Captions one of two ways:
– Create from scratch: using “File > New > Captions…”, you can create an Open Captions project item the same way as Closed Captions (just select Standard: “Open Caption”). The resulting project item contains one default caption.
– Select an arbitrary project item that already contains a closed caption and select the action “Modify > Captions…” and select Standard: “Open Caption”.
Because the second method of creating subtitles from an existing Closed Captions file is a common workflow, I’ll describe it in more detail.
Creating Open Captions from Closed Captions:
If you modify an existing Closed Captions item to become Open Captions, it won’t update the original file. The info about the new Open Captions item is stored within the Premiere Pro project (same as for Closed Captions).
Note: If you import the original Closed Caption file again, it will also be shown as an Open Caption in the project, because the caption info is bound to its file path. If you need to see the original caption in the project, you should copy the file on disk first and then modify the copy.
Because Open Captions can contain more formatting options than Closed Captions permit, Premiere Pro currently doesn’t have an option to switch Open Captions back to Closed Captions. (If you select “Modify – Captions” for Open Captions, you can’t select a Closed Caption format).
Note: The only way to revert back to Closed Captions is: remove the project item from your project, save and close the project and remove the related info from Media Cache (to be sure that the info is not cached). After that you can re-import the item again with its original Closed Captions content).
To prevent confusion by mixing Open and Closed Captions, we only allow users to modify Closed Captions that contain a single stream format (e.g. if your file contains CEA-608 CC1 and CEA-608 CC2, the option to modify it to “Open Caption” is not available).
You can update Open Captions in the Captions Panel (similar to Closed Captions), but the controls are a bit different:
Changes you make in the Captions panel should be visible in the Source or Program-Monitor immediately (no save or “OK” button required).
The Captions panel controls for Open Captions are similar to those for Closed Captions. I’ll only describe the formatting options that are available exclusively for Open Captions:
Font Size: determines the size of the selected text. (Tip: when you use the Return key, the next line is positioned with a vertical spacing of half the selected height).
Font Family: selects one of the font families available on your system (Note: not every font is supported; if it’s unsupported, Premiere will use a default font)
Font Weight: select one of the font weights for the selected font family. Premiere Pro currently handles the most common weights (Bold, Italic, Regular, Bold Italic). The selected style is kept in sync with “Italic” and “Bold” selections. For example, if the font family doesn’t have an “Italic” weight, the Italic button is set to “None” and disabled.
Color: similar to closed captions: select the mode first (foreground or background), then select a color. For Open Captions, you’ll use a Color Picker with virtually unlimited colors to choose from.
Positioning: There are 2 ways to position a paragraph:
– Directly: using the x: and y: fields. The input is given in “%”. It describes the position within the “Caption Area” (10% of the weight/height of it is a “Caption-free border”, so we use the inner 80% of the Video frame). The positioning is calculated “pixel-precise” internally, so typing 30% may result to something like 29.88%.
– By Positioning Block control: This control allows you to put the captions in one of the 9 “corners” of the “Caption Area”.
Closed Captions are “grid based”, meaning they contain a fixed number of rows and columns. Open Captions don’t have this limitation. We can select the font size in absolute pixels (e.g. a 20px size text character looks much smaller in a 1920 x 1080px video frame than in a 720 x 480px video, but it takes the same amount of pixels in both frame sizes).
We can also select the position of Open Caption text with pixel precision. And the best feature of free positioning with Open Captions is that is uses proportionally spaced letters (an “i” takes less space than an “m”), which is easier to read and looks more natural.
The easiest way to position a group of rows is the “Position Caption Block” control in the Captions panel. All selected rows get one of 9 defined positions (or if none: all rows in the caption). All rows form a group. The space between the lines is defined by the font size. The horizontal positioning of the lines within the block depends on the Alignment Setting (left, center, right), where the longest row defines the “left” and “right”. The resulting block (height defined by number of rows and their font size, width defined by the longest row in block) are positioned in the given “corner” of the Caption Area.
If you add a new row, it is positioned by default after the current row (in the same block). If the block reaches the bottom of Caption area, all lines of the block are re-positioned so that the last row ends at the bottom of the Caption Area. The same happens with added text in a row. If this would exceed the Caption area, the block is automatically repositioned.
If you position a single row directly (using x: and y:), it will no longer be part of the block any more (the rest of the positioned block is kept together). If you’re not careful, you can create “collisions” with other rows in the Caption area, so use the Position Caption Block control with care. My recommendation is to position the first row where you want it, and other rows created with the “Return” key will follow the first row and build a new block. If you select more rows for free positioning, the first one will get the given position, the other ones will follow.
If you type invalid positions (e.g. a caption can never be positioned at 100% – this would start outside the visible caption area), the row (or the selected block) is positioned to the “next-best” valid position.
Export Open Captions:
Open Captions are burned into the video because they’re handled as a normal video layer. The only way to prevent burn-in of the Open Captions is to hide the caption track in the Timeline (click on the “Toggle Track Output” eyeball icon in the video track header).
Topics: Video & Audio
Products: Premiere Pro, Creative Cloud