.PPTX File Format – Slides and shapes

Office Open XML Presentation

Each slide is its own part, such as ppt/slides/slide1.xml, with the root element p:sld. The part names say nothing about the order: that comes from p:sldIdLst. A slide’s relationships lead to its layout, notes, comments and media.

<p:sld xmlns:p="…" xmlns:a="…" xmlns:r="…" show="1">
  <p:cSld>
    <p:spTree>
      <p:nvGrpSpPr>…</p:nvGrpSpPr>
      <p:grpSpPr/>
      <p:sp>
        <p:nvSpPr>
          <p:cNvPr id="2" name="Title 1"/>
          <p:cNvSpPr/>
          <p:nvPr><p:ph type="title"/></p:nvPr>
        </p:nvSpPr>
        <p:spPr/>
        <p:txBody>
          <a:bodyPr/>
          <a:p><a:r><a:t>A title</a:t></a:r></a:p>
        </p:txBody>
      </p:sp>
    </p:spTree>
  </p:cSld>
</p:sld>
A slide with one title shape.

The shape tree

p:spTree holds the slide’s shapes, in drawing order: the first is at the back. It is itself a group.

ElementIs
p:spA shape: an auto-shape, a text box or a placeholder.
p:picA picture: p:blipFill/a:blip names the image by r:embed or r:link.
p:graphicFrameA frame for a table, a chart, a SmartArt diagram or an embedded object.
p:grpSpA group that holds more of these.
p:cxnSpA connector.
mc:AlternateContentMarkup compatibility: a mc:Choice for readers that know a feature and a mc:Fallback for those that do not.

Shape properties

Each shape has a non-visual part (p:nvSpPr: id and name, and in p:nvPr a placeholder p:ph) and visual properties in p:spPr: position and size in a:xfrm (in EMUs), geometry and line.

A placeholder shape has a p:ph whose type is one of title, ctrTitle, subTitle, body, obj, chart, tbl, dgm, pic, dt, ftr, sldNum, and others, and whose idx links it to the placeholder on the layout.

Tables, charts and diagrams

A p:graphicFrame holds an a:graphic whose a:graphicData has a uri saying what it is.

uri ends inHolds
/drawingml/2006/tablea:tbl with a:tr rows and a:tc cells, each with an a:txBody.
/drawingml/2006/chartA c:chart with an r:id to a chart part.
/drawingml/2006/diagramdgm:relIds pointing to the diagram’s data, layout, style and colour parts.
/presentationml/2006/oleAn embedded OLE object.

Slide settings

On p:sld, show="0" hides a slide from the show. Transitions and animations are in p:transition and p:timing, after p:clrMapOvr.