Caching / Pre-rendering

To avoid excessive memory consumption, cached are only slides that took a significant time to render; this threshold is configurable. In order to further reduce memory consumption, the pre-rendered and cached slides are selectively compressed in memory. The compression factor is typically 10-30, however, it takes some CPU time to compress and uncompress, so there is a trade-off. Small images below a certain (configurable) threshold will not be compressed.

Please refer to the pdfpcrc(5) man page for options to fine tune the caching algorithm.

Timer

The timer is started if you are navigating away from the first page for the first time. This feature is quite useful as you may want to show the title page of your presentation while people are still entering the room and the presentation has not really begun yet. If you want to start over you can use the 'Ctrl + t' key which will make the presenter reset the timer.

If a duration is given, the timer also provides hints aiding the presenter to judge whether the talk would end on time. There are two modes in which pdfpc can operate. In the old (and the only one available up to, and including pdfpc-4.0.8) mode, at the moment the timer reaches the defined last-minutes value it will change color to indicate your talk is nearing its end, thus mimicking a chairman frantically pantomiming in front of you with five (four, three, ...) fingers up. A drawback of this approach is it is often too late at that moment to alter the presentation pace without ruining to some extent the rest of the talk. On the other hand, the warning indication provides an unnecessary distraction if you have been perfectly conveying the talk and the remaining time is adequate.

Contrary to that, in the new (default) mode, pdfpc tracks your progress continuously, calculating the expected time as (talk_duration)*(current_user_slide_number - 0.5)/(total_number_of_user_slides) and comparing it to the actual wall time since beginning of the talk. If these two numbers differ by more than 60 seconds, the timer changes its color to either orange (indicating you need to speed up) or a blueish one (need to slow down). Once the optimal progress is recovered, the timer becomes white again. In this mode, the last-minutes option (-l) has no effect. The previous behavior can be restored by setting the 'timer-pace-color' option to 'false' in the configuration file, see pdfpcrc(5).

In any case as soon as the timer reaches the zero mark (00:00:00), it will turn red and count further down showing a negative time, to provide information on how many minutes you are overtime.

Notes

In addition, while in the presentation mode, pressing 'Ctrl + n' will allow you to take or edit notes for the current user slide. To exit the note editing mode, press the Escape key. These notes are stored in the .pdfpc file. They take precedence over the native PDF annotations, i.e., if a user-provided note exists for a given slide, any PDF annotations on that page will be silently ignored. While editing a note, the normal keybindings are disabled, e.g., you are not able to change slides.

Although mixing the two types of notes is possible, for a given presentation one will likely want to have either only the "native" notes (produced by the same PDF authoring software used for making the slides), or only the "pdfpc" ones.

Overview mode

Overlays

In this description, we will differentiate between slides (i.e. pages in the PDF document) and "user slides", that are the logical slides. The standard forward movement command (page down, enter, etc.) moves through one slide at a time, as expected. This means that every step in the overlay is traversed. The backward movement command works differently depending on whether the current and previous slides are part of an overlay:

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If the current slide is part of an overlay we just jump to the previous slide. That means that we are in the middle of an overlay and can jump forward and backward through the single steps of it

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If the current slide is not part of an overlay (or if it is the first one), but the previous slides are, we jump to the previous user slide. This means that when going back in the presentation you do not have to go through every step of the overlay, pdfpc just shows the first slide of each overlay. As one typically goes back in a presentation only when looking for a concrete slide, this is more convenient.

The Shift + Page up/down key combinations work on the "user slide" basis. You can use them to skip the rest of an overlay or to jump to the previous user slide, ignoring the state of the current slide.

When going through an overlay, two additional previews may be activated in the presenter view, just below the main view, showing the next and the previous slide in an overlay.

Pdfpc tries to find these overlays automatically by looking into the page labels in the PDF file. For LaTeX this works correctly at least with the beamer class and also modifying the page numbers manually (compiling with pdflatex). If your preferred slide-producing method does not work correctly with this detection, you can supply this information using the 'Ctrl + o' key for each slide that is part of an overlay (except the first one!). The page numbering is also adapted. This information is automatically stored.

End slide

Page transitions

Advancing slides automatically is also supported.

Movies

Movies may be included in PDF files as "screen annotations". pdfpc does not yet support options that modify the playback of these movies. In LaTeX, such movies may be added to a presentation with the "movie15" or "multimedia" package. Note that the poster, autoplay, and repeat options are not yet supported. (Also, run ps2pdf with the -dNOSAFER flag.)

As a perhaps simpler option, pdfpc will play back movies linked from a hyperlink of type "launch". A query string may be added to the URL of the movie to enable the "autostart", "loop" and "noprogress" properties, if necessary. (E.g., a link to "movie.avi?autostart&loop&noprogress" will add a video that starts playing automatically, loops when it reaches the end, and does not show the progress bar.)

In LaTeX, such links are created with

The movie will playback in the area taken by the placeholder content. Using a frame of the movie will ensure the correct aspect ratio.

See our website ⟨URL: http://pdfpc.github.io/demo/pdfpc-video-example.zip ⟩ for a full example.

See the bugs section for further information.

Pointer mode

Spotlight mode

Drawing mode

In the drawing mode, there are two drawing tools, a pen and an eraser. An indicator in the bottom-left corner of the presenter screen will indicate which is active. When in the pen mode, the color and size of the pen will be indicated by the cursor. The pen size can be increased or decreased using hot keys specified in the key bindings. When the eraser tool is active, the size of the cursor indicates the amount to erase.

The color of the pen can be changed through key bindings or using the toolbox.

If you are using a tablet, the pen or eraser tool will be selected based on whether the tablet reports a pen or eraser input device is being used, overriding the normal selection of the drawing tool. Also for pressure-sensitive input devices, the pressure will affect the line width and the eraser size. Both these features can be disabled in the configuration file, if desired.

Monitor Plug and Play

pdfpc files

Beside internal configuration, the following command-line options are saved in the pdfpc file for later usage:

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duration

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end_time

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last_minutes

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notes (position)

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page_transition

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start_time

Appearance

The geometry of various views (the current/next etc slide) in the presenter window can be adjusted at run time in the "Customization" mode, which is activated by pressing Shift+c. In this mode, mouse-draggable handles will appear. Exit the customization with Escape.

Desktop integration

dbus-send --type=method_call --session --dest=io.github.pdfpc /io/github/pdfpc io.github.pdfpc.TriggerAction string:next

For actions that require an argument, use TriggerActionArg, e.g.,

dbus-send --type=method_call --session --dest=io.github.pdfpc /io/github/pdfpc io.github.pdfpc.TriggerActionArg string:switchMode string:pointer

In addition to TriggerAction*, the pdfpc DBus interface exposes the GetNotes method, three properties (NumberOfOverlays, NumberOfSlides, Url) and two signals (OverlayChange and SlideChange).

LaTeX package