Add an audio file to a slide in a presentation

2025-05-12

This topic shows how to use the classes in the Open XML SDK for Office to add an audio file to the last slide in a presentation programmatically.

Getting a Presentation Object

In the Open XML SDK, the PresentationDocument class represents a presentation document package. To work with a presentation document, first create an instance of the PresentationDocument class, and then work with that instance. To create the class instance from the document call the Open method that uses a file path, and a Boolean value as the second parameter to specify whether a document is editable. To open a document for read/write, specify the value true for this parameter as shown in the following using statement. In this code, the file parameter is a string that represents the path for the file from which you want to open the document.

C#
Visual Basic

using (PresentationDocument presentationDocument = PresentationDocument.Open(filePath, true))

Using presentationDocument As PresentationDocument = PresentationDocument.Open(filePath, True)

With v3.0.0+ the Close() method has been removed in favor of relying on the using statement. This ensures that the Dispose() method is automatically called when the closing brace is reached. The block that follows the using statement establishes a scope for the object that is created or named in the using statement, in this case ppt.

The Structure of the Audio From File

The PresentationML document consists of a number of parts, among which is the Picture (<pic/>) element.

The following text from the ISO/IEC 29500 specification introduces the overall form of a PresentationML package.

Audio File (<audioFile/>) specifies the presence of an audio file. This element is specified within the non-visual properties of an object. The audio shall be attached to an object as this is how it is represented within the document. The actual playing of the audio however is done within the timing node list that is specified under the timing element.

Consider the following Picture object that has an audio file attached to it.

<p:pic>  
  <p:nvPicPr>  
    <p:cNvPr id="7" name="Rectangle 6">  
      <a:hlinkClick r:id="" action="ppaction://media"/>  
    </p:cNvPr>  
    <p:cNvPicPr>  
      <a:picLocks noRot="1"/>  
    </p:cNvPicPr>  
    <p:nvPr>  
      <a:audioFile r:link="rId1"/>  
    </p:nvPr>  
  </p:nvPicPr>  
</p:pic>

In the above example, we see that there is a single audioFile element attached to this picture. This picture is placed within the document just as a normal picture or shape would be. The id of this picture, namely 7 in this case, is used to refer to this audioFile element from within the timing node list. The Linked relationship id is used to retrieve the actual audio file for playback purposes.

The following XML Schema fragment defines the contents of audioFile.

<xsd:complexType name="CT_TLMediaNodeAudio">
	<xsd:sequence>
		<xsd:element name="cMediaNode" type="CT_TLCommonMediaNodeData" minOccurs="1" maxOccurs="1"/>
	</xsd:sequence>
  <xsd:attribute name="isNarration" type="xsd:boolean" use="optional" default="false"/>
</xsd:complexType>

How the Sample Code Works

After opening the presentation file for read/write access in the using statement, the code gets the presentation part from the presentation document. Then it gets the relationship ID of the last slide, and gets the slide part from the relationship ID.

C#
Visual Basic

//Get presentation part
PresentationPart presentationPart = presentationDocument.PresentationPart;

//Get slides ids.
OpenXmlElementList slidesIds = presentationPart.Presentation.SlideIdList.ChildElements;

//Get relationsipId of the last slide
string? audioSlidePartRelationshipId = ((SlideId)slidesIds[slidesIds.ToArray().Length - 1]).RelationshipId;

if (audioSlidePartRelationshipId == null)
{
    throw new NullReferenceException("Slide id not found");
}

//Get slide part by relationshipID
SlidePart? slidePart = (SlidePart)presentationPart.GetPartById(audioSlidePartRelationshipId);

' Get presentation part
Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

' Get slides ids
Dim slidesIds As OpenXmlElementList = presentationPart.Presentation.SlideIdList.ChildElements

' Get relationshipId of the last slide
Dim audioSldRelationshipId As String = CType(slidesIds(slidesIds.ToArray().Length - 1), SlideId).RelationshipId

If audioSldRelationshipId Is Nothing Then
    Throw New NullReferenceException("Slide id not found")
End If

' Get slide part by relationshipID
Dim slidePart As SlidePart = CType(presentationPart.GetPartById(audioSldRelationshipId), SlidePart)

The code first creates a media data part for the audio file to be added. With the audio file stream open, it feeds the media data part object. Next, audio and media relationship references are added to the slide using the provided embedId for future reference to the audio file and mediaEmbedId for media reference.

An image part is then added with a sample picture to be used as a placeholder for the audio. A picture object is created with various elements, such as Non-Visual Drawing Properties (<cNvPr/>), which specify non-visual canvas properties. This allows for additional information that does not affect the appearance of the picture to be stored. The <audioFile/> element, explained above, is also included. The HyperLinkOnClick (<hlinkClick/>) element specifies the on-click hyperlink information to be applied to a run of text or image. When the hyperlink text or image is clicked, the link is fetched. Non-Visual Picture Drawing Properties (<cNvPicPr/>) specify the non-visual properties for the picture canvas. For a detailed explanation of the elements used, please refer to ISO/IEC 29500

C#
Visual Basic

// Create audio Media Data Part (content type, extension)
MediaDataPart mediaDataPart = presentationDocument.CreateMediaDataPart("audio/mp3", ".mp3");

//Get the audio file and feed the stream
using (Stream mediaDataPartStream = File.OpenRead(audioFilePath))
{
    mediaDataPart.FeedData(mediaDataPartStream);
}
//Adds a AudioReferenceRelationship to the MainDocumentPart
slidePart.AddAudioReferenceRelationship(mediaDataPart, embedId);

//Adds a MediaReferenceRelationship to the SlideLayoutPart
slidePart.AddMediaReferenceRelationship(mediaDataPart, mediaEmbedId);

NonVisualDrawingProperties nonVisualDrawingProperties = new NonVisualDrawingProperties() { Id = shapeId, Name = "audio" };
A.AudioFromFile audioFromFile = new A.AudioFromFile() { Link = embedId };

ApplicationNonVisualDrawingProperties appNonVisualDrawingProperties = new ApplicationNonVisualDrawingProperties();
appNonVisualDrawingProperties.Append(audioFromFile);

//adds sample image to the slide with id to be used as reference in blip
ImagePart imagePart = slidePart.AddImagePart(ImagePartType.Png, imgEmbedId);
using (Stream data = File.OpenRead(coverPicPath))
{
    imagePart.FeedData(data);
}

if (slidePart!.Slide!.CommonSlideData!.ShapeTree == null)
{
    throw new NullReferenceException("Presentation shape tree is empty");
}

//Getting existing shape tree element from PowerPoint
ShapeTree shapeTree = slidePart.Slide.CommonSlideData.ShapeTree;

// specifies the existence of a picture within a presentation.
// It can have non-visual properties, a picture fill as well as shape properties attached to it.
Picture picture = new Picture();
NonVisualPictureProperties nonVisualPictureProperties = new NonVisualPictureProperties();

A.HyperlinkOnClick hyperlinkOnClick = new A.HyperlinkOnClick() { Id = "", Action = "ppaction://media" };
nonVisualDrawingProperties.Append(hyperlinkOnClick);

NonVisualPictureDrawingProperties nonVisualPictureDrawingProperties = new NonVisualPictureDrawingProperties();
A.PictureLocks pictureLocks = new A.PictureLocks() { NoChangeAspect = true };
nonVisualPictureDrawingProperties.Append(pictureLocks);

ApplicationNonVisualDrawingPropertiesExtensionList appNonVisualDrawingPropertiesExtensionList = new ApplicationNonVisualDrawingPropertiesExtensionList();
ApplicationNonVisualDrawingPropertiesExtension appNonVisualDrawingPropertiesExtension = new ApplicationNonVisualDrawingPropertiesExtension() { Uri = "{DAA4B4D4-6D71-4841-9C94-3DE7FCFB9230}" };

' Create video Media Data Part (content type, extension)
Dim mediaDataPart As MediaDataPart = presentationDocument.CreateMediaDataPart("video/mp4", ".mp4")

' Get the audio file and feed the stream
Using mediaDataPartStream As Stream = File.OpenRead(audioFilePath)
    mediaDataPart.FeedData(mediaDataPartStream)
End Using

' Adds a AudioReferenceRelationship to the MainDocumentPart
slidePart.AddAudioReferenceRelationship(mediaDataPart, embedId)

' Adds a MediaReferenceRelationship to the SlideLayoutPart
slidePart.AddMediaReferenceRelationship(mediaDataPart, mediaEmbedId)

Dim nonVisualDrawingProperties As New NonVisualDrawingProperties() With {
    .Id = shapeId,
    .Name = "audio"
}
Dim audioFromFile As New A.AudioFromFile() With {
    .Link = embedId
}

Dim appNonVisualDrawingProperties As New ApplicationNonVisualDrawingProperties()
appNonVisualDrawingProperties.Append(audioFromFile)

' Adds sample image to the slide with id to be used as reference in blip
Dim imagePart As ImagePart = slidePart.AddImagePart(ImagePartType.Png, imgEmbedId)
Using data As Stream = File.OpenRead(coverPicPath)
    imagePart.FeedData(data)
End Using

If slidePart.Slide.CommonSlideData.ShapeTree Is Nothing Then
    Throw New NullReferenceException("Presentation shape tree is empty")
End If

' Getting existing shape tree object from PowerPoint
Dim shapeTree As ShapeTree = slidePart.Slide.CommonSlideData.ShapeTree

' Specifies the existence of a picture within a presentation
Dim picture As New Picture()
Dim nonVisualPictureProperties As New NonVisualPictureProperties()

Dim hyperlinkOnClick As New A.HyperlinkOnClick() With {
    .Id = "",
    .Action = "ppaction://media"
}
nonVisualDrawingProperties.Append(hyperlinkOnClick)

Dim nonVisualPictureDrawingProperties As New NonVisualPictureDrawingProperties()
Dim pictureLocks As New A.PictureLocks() With {
    .NoChangeAspect = True
}
nonVisualPictureDrawingProperties.Append(pictureLocks)

Dim appNonVisualDrawingPropertiesExtensionList As New ApplicationNonVisualDrawingPropertiesExtensionList()
Dim appNonVisualDrawingPropertiesExtension As New ApplicationNonVisualDrawingPropertiesExtension() With {
    .Uri = "{DAA4B4D4-6D71-4841-9C94-3DE7FCFB9230}"
}

Next the Media(CT_Media) element is created with use of the previously referenced mediaEmbedId(Embedded Picture Reference). The Blip element is also added; this element specifies the existence of an image (binary large image or picture) and contains a reference to the image data. Blip's Embed attribute is used to specify an placeholder image in the Image Part created previously.

C#
Visual Basic

P14.Media media = new() { Embed = mediaEmbedId };
media.AddNamespaceDeclaration("p14", "http://schemas.microsoft.com/office/powerpoint/2010/main");

appNonVisualDrawingPropertiesExtension.Append(media);
appNonVisualDrawingPropertiesExtensionList.Append(appNonVisualDrawingPropertiesExtension);
appNonVisualDrawingProperties.Append(appNonVisualDrawingPropertiesExtensionList);

nonVisualPictureProperties.Append(nonVisualDrawingProperties);
nonVisualPictureProperties.Append(nonVisualPictureDrawingProperties);
nonVisualPictureProperties.Append(appNonVisualDrawingProperties);

//Prepare shape properties to display picture
BlipFill blipFill = new BlipFill();
A.Blip blip = new A.Blip() { Embed = imgEmbedId };

Dim media As New P14.Media() With {
    .Embed = mediaEmbedId
}
media.AddNamespaceDeclaration("p14", "http://schemas.microsoft.com/office/powerpoint/2010/main")

appNonVisualDrawingPropertiesExtension.Append(media)
appNonVisualDrawingPropertiesExtensionList.Append(appNonVisualDrawingPropertiesExtension)
appNonVisualDrawingProperties.Append(appNonVisualDrawingPropertiesExtensionList)

nonVisualPictureProperties.Append(nonVisualDrawingProperties)
nonVisualPictureProperties.Append(nonVisualPictureDrawingProperties)
nonVisualPictureProperties.Append(appNonVisualDrawingProperties)

' Prepare shape properties to display picture
Dim blipFill As New BlipFill()
Dim blip As New A.Blip() With {
    .Embed = imgEmbedId
}

All other elements such as Offset(<off/>), Stretch(<stretch/>), fillRectangle(<fillRect/>), are appended to the ShapeProperties(<spPr/>) and ShapeProperties are appended to the Picture element(<pic/>). Finally the picture element that includes audio is added to the ShapeTree(<sp/>) of the slide.

Following is the complete sample code that you can use to add audio to the slide.

AddAudio(args[0], args[1], args[2]);

static void AddAudio(string filePath, string audioFilePath, string coverPicPath)
{

    string imgEmbedId = "rId4", embedId = "rId3", mediaEmbedId = "rId2";
    UInt32Value shapeId = 5;
    using (PresentationDocument presentationDocument = PresentationDocument.Open(filePath, true))
    {

        if (presentationDocument.PresentationPart == null || presentationDocument.PresentationPart.Presentation.SlideIdList == null)
        {
            throw new NullReferenceException("Presentation Part is empty or there are no slides in it");
        }

        //Get presentation part
        PresentationPart presentationPart = presentationDocument.PresentationPart;

        //Get slides ids.
        OpenXmlElementList slidesIds = presentationPart.Presentation.SlideIdList.ChildElements;

        //Get relationsipId of the last slide
        string? audioSlidePartRelationshipId = ((SlideId)slidesIds[slidesIds.ToArray().Length - 1]).RelationshipId;

        if (audioSlidePartRelationshipId == null)
        {
            throw new NullReferenceException("Slide id not found");
        }

        //Get slide part by relationshipID
        SlidePart? slidePart = (SlidePart)presentationPart.GetPartById(audioSlidePartRelationshipId);

        // Create audio Media Data Part (content type, extension)
        MediaDataPart mediaDataPart = presentationDocument.CreateMediaDataPart("audio/mp3", ".mp3");

        //Get the audio file and feed the stream
        using (Stream mediaDataPartStream = File.OpenRead(audioFilePath))
        {
            mediaDataPart.FeedData(mediaDataPartStream);
        }
        //Adds a AudioReferenceRelationship to the MainDocumentPart
        slidePart.AddAudioReferenceRelationship(mediaDataPart, embedId);

        //Adds a MediaReferenceRelationship to the SlideLayoutPart
        slidePart.AddMediaReferenceRelationship(mediaDataPart, mediaEmbedId);

        NonVisualDrawingProperties nonVisualDrawingProperties = new NonVisualDrawingProperties() { Id = shapeId, Name = "audio" };
        A.AudioFromFile audioFromFile = new A.AudioFromFile() { Link = embedId };

        ApplicationNonVisualDrawingProperties appNonVisualDrawingProperties = new ApplicationNonVisualDrawingProperties();
        appNonVisualDrawingProperties.Append(audioFromFile);

        //adds sample image to the slide with id to be used as reference in blip
        ImagePart imagePart = slidePart.AddImagePart(ImagePartType.Png, imgEmbedId);
        using (Stream data = File.OpenRead(coverPicPath))
        {
            imagePart.FeedData(data);
        }

        if (slidePart!.Slide!.CommonSlideData!.ShapeTree == null)
        {
            throw new NullReferenceException("Presentation shape tree is empty");
        }

        //Getting existing shape tree element from PowerPoint
        ShapeTree shapeTree = slidePart.Slide.CommonSlideData.ShapeTree;

        // specifies the existence of a picture within a presentation.
        // It can have non-visual properties, a picture fill as well as shape properties attached to it.
        Picture picture = new Picture();
        NonVisualPictureProperties nonVisualPictureProperties = new NonVisualPictureProperties();

        A.HyperlinkOnClick hyperlinkOnClick = new A.HyperlinkOnClick() { Id = "", Action = "ppaction://media" };
        nonVisualDrawingProperties.Append(hyperlinkOnClick);

        NonVisualPictureDrawingProperties nonVisualPictureDrawingProperties = new NonVisualPictureDrawingProperties();
        A.PictureLocks pictureLocks = new A.PictureLocks() { NoChangeAspect = true };
        nonVisualPictureDrawingProperties.Append(pictureLocks);

        ApplicationNonVisualDrawingPropertiesExtensionList appNonVisualDrawingPropertiesExtensionList = new ApplicationNonVisualDrawingPropertiesExtensionList();
        ApplicationNonVisualDrawingPropertiesExtension appNonVisualDrawingPropertiesExtension = new ApplicationNonVisualDrawingPropertiesExtension() { Uri = "{DAA4B4D4-6D71-4841-9C94-3DE7FCFB9230}" };

        P14.Media media = new() { Embed = mediaEmbedId };
        media.AddNamespaceDeclaration("p14", "http://schemas.microsoft.com/office/powerpoint/2010/main");

        appNonVisualDrawingPropertiesExtension.Append(media);
        appNonVisualDrawingPropertiesExtensionList.Append(appNonVisualDrawingPropertiesExtension);
        appNonVisualDrawingProperties.Append(appNonVisualDrawingPropertiesExtensionList);

        nonVisualPictureProperties.Append(nonVisualDrawingProperties);
        nonVisualPictureProperties.Append(nonVisualPictureDrawingProperties);
        nonVisualPictureProperties.Append(appNonVisualDrawingProperties);

        //Prepare shape properties to display picture
        BlipFill blipFill = new BlipFill();
        A.Blip blip = new A.Blip() { Embed = imgEmbedId };

        A.Stretch stretch = new A.Stretch();
        A.FillRectangle fillRectangle = new A.FillRectangle();
        A.Transform2D transform2D = new A.Transform2D();
        A.Offset offset = new A.Offset() { X = 1524000L, Y = 857250L };
        A.Extents extents = new A.Extents() { Cx = 9144000L, Cy = 5143500L };
        A.PresetGeometry presetGeometry = new A.PresetGeometry() { Preset = A.ShapeTypeValues.Rectangle };
        A.AdjustValueList adjValueList = new A.AdjustValueList();

        stretch.Append(fillRectangle);
        blipFill.Append(blip);
        blipFill.Append(stretch);
        transform2D.Append(offset);
        transform2D.Append(extents);
        presetGeometry.Append(adjValueList);

        ShapeProperties shapeProperties = new ShapeProperties();
        shapeProperties.Append(transform2D);
        shapeProperties.Append(presetGeometry);

        //adds all elements to the slide's shape tree
        picture.Append(nonVisualPictureProperties);
        picture.Append(blipFill);
        picture.Append(shapeProperties);

        shapeTree.Append(picture);

    }
}

Module Program
    Sub Main(args As String())
        AddAudio(args(0), args(1), args(2))
    End Sub

    Sub AddAudio(filePath As String, audioFilePath As String, coverPicPath As String)
        Dim imgEmbedId As String = "rId4"
        Dim embedId As String = "rId3"
        Dim mediaEmbedId As String = "rId2"
        Dim shapeId As UInt32Value = 5

        Using presentationDocument As PresentationDocument = PresentationDocument.Open(filePath, True)
            If presentationDocument.PresentationPart Is Nothing OrElse presentationDocument.PresentationPart.Presentation.SlideIdList Is Nothing Then
                Throw New NullReferenceException("Presentation Part is empty or there are no slides in it")
            End If
            ' Get presentation part
            Dim presentationPart As PresentationPart = presentationDocument.PresentationPart

            ' Get slides ids
            Dim slidesIds As OpenXmlElementList = presentationPart.Presentation.SlideIdList.ChildElements

            ' Get relationshipId of the last slide
            Dim audioSldRelationshipId As String = CType(slidesIds(slidesIds.ToArray().Length - 1), SlideId).RelationshipId

            If audioSldRelationshipId Is Nothing Then
                Throw New NullReferenceException("Slide id not found")
            End If

            ' Get slide part by relationshipID
            Dim slidePart As SlidePart = CType(presentationPart.GetPartById(audioSldRelationshipId), SlidePart)
            ' Create video Media Data Part (content type, extension)
            Dim mediaDataPart As MediaDataPart = presentationDocument.CreateMediaDataPart("video/mp4", ".mp4")

            ' Get the audio file and feed the stream
            Using mediaDataPartStream As Stream = File.OpenRead(audioFilePath)
                mediaDataPart.FeedData(mediaDataPartStream)
            End Using

            ' Adds a AudioReferenceRelationship to the MainDocumentPart
            slidePart.AddAudioReferenceRelationship(mediaDataPart, embedId)

            ' Adds a MediaReferenceRelationship to the SlideLayoutPart
            slidePart.AddMediaReferenceRelationship(mediaDataPart, mediaEmbedId)

            Dim nonVisualDrawingProperties As New NonVisualDrawingProperties() With {
                .Id = shapeId,
                .Name = "audio"
            }
            Dim audioFromFile As New A.AudioFromFile() With {
                .Link = embedId
            }

            Dim appNonVisualDrawingProperties As New ApplicationNonVisualDrawingProperties()
            appNonVisualDrawingProperties.Append(audioFromFile)

            ' Adds sample image to the slide with id to be used as reference in blip
            Dim imagePart As ImagePart = slidePart.AddImagePart(ImagePartType.Png, imgEmbedId)
            Using data As Stream = File.OpenRead(coverPicPath)
                imagePart.FeedData(data)
            End Using

            If slidePart.Slide.CommonSlideData.ShapeTree Is Nothing Then
                Throw New NullReferenceException("Presentation shape tree is empty")
            End If

            ' Getting existing shape tree object from PowerPoint
            Dim shapeTree As ShapeTree = slidePart.Slide.CommonSlideData.ShapeTree

            ' Specifies the existence of a picture within a presentation
            Dim picture As New Picture()
            Dim nonVisualPictureProperties As New NonVisualPictureProperties()

            Dim hyperlinkOnClick As New A.HyperlinkOnClick() With {
                .Id = "",
                .Action = "ppaction://media"
            }
            nonVisualDrawingProperties.Append(hyperlinkOnClick)

            Dim nonVisualPictureDrawingProperties As New NonVisualPictureDrawingProperties()
            Dim pictureLocks As New A.PictureLocks() With {
                .NoChangeAspect = True
            }
            nonVisualPictureDrawingProperties.Append(pictureLocks)

            Dim appNonVisualDrawingPropertiesExtensionList As New ApplicationNonVisualDrawingPropertiesExtensionList()
            Dim appNonVisualDrawingPropertiesExtension As New ApplicationNonVisualDrawingPropertiesExtension() With {
                .Uri = "{DAA4B4D4-6D71-4841-9C94-3DE7FCFB9230}"
            }
            Dim media As New P14.Media() With {
                .Embed = mediaEmbedId
            }
            media.AddNamespaceDeclaration("p14", "http://schemas.microsoft.com/office/powerpoint/2010/main")

            appNonVisualDrawingPropertiesExtension.Append(media)
            appNonVisualDrawingPropertiesExtensionList.Append(appNonVisualDrawingPropertiesExtension)
            appNonVisualDrawingProperties.Append(appNonVisualDrawingPropertiesExtensionList)

            nonVisualPictureProperties.Append(nonVisualDrawingProperties)
            nonVisualPictureProperties.Append(nonVisualPictureDrawingProperties)
            nonVisualPictureProperties.Append(appNonVisualDrawingProperties)

            ' Prepare shape properties to display picture
            Dim blipFill As New BlipFill()
            Dim blip As New A.Blip() With {
                .Embed = imgEmbedId
            }
            Dim stretch As New A.Stretch()
            Dim fillRectangle As New A.FillRectangle()
            Dim transform2D As New A.Transform2D()
            Dim offset As New A.Offset() With {
                .X = 1524000L,
                .Y = 857250L
            }
            Dim extents As New A.Extents() With {
                .Cx = 9144000L,
                .Cy = 5143500L
            }
            Dim presetGeometry As New A.PresetGeometry() With {
                .Preset = A.ShapeTypeValues.Rectangle
            }
            Dim adjValueList As New A.AdjustValueList()

            stretch.Append(fillRectangle)
            blipFill.Append(blip)
            blipFill.Append(stretch)
            transform2D.Append(offset)
            transform2D.Append(extents)
            presetGeometry.Append(adjValueList)

            Dim shapeProperties As New ShapeProperties()
            shapeProperties.Append(transform2D)
            shapeProperties.Append(presetGeometry)

            ' Adds all elements to the slide's shape tree
            picture.Append(nonVisualPictureProperties)
            picture.Append(blipFill)
            picture.Append(shapeProperties)

            shapeTree.Append(picture)
        End Using
    End Sub
End Module

Share via

Add an audio file to a slide in a presentation

Getting a Presentation Object

The Structure of the Audio From File

How the Sample Code Works

Sample Code

See also

Additional resources