Tts Voiceover

TTS Voice Over Skill

Generates per-slide WAV voice-over files from YAML speaker_notes using Azure Speech SDK with SSML pronunciation control.

Overview

This skill reads content.yaml files from a PowerPoint skill content directory, extracts speaker_notes fields, applies SSML acronym aliases for correct pronunciation of technical terms, and produces one WAV file per slide. Supports dry-run mode for SSML template verification without Azure credentials.

Prerequisites

• Azure Speech resource — Free tier provides 500K characters per month.
• Authentication — Key-based (SPEECH_KEY) or Microsoft Entra ID (SPEECH_RESOURCE_ID).
• Python 3.11+ with uv for virtual environment management.
• Data handling note — Speaker-notes content is transmitted to the configured SPEECH_REGION for synthesis. Operators must pin an approved region and avoid sending regulated or confidential narration.

Key-Based Auth

export SPEECH_KEY="your-speech-key"
export SPEECH_REGION="eastus"

Microsoft Entra ID Auth

Requires a custom domain on the Speech resource and Cognitive Services Speech User role.

export SPEECH_RESOURCE_ID="/subscriptions/.../Microsoft.CognitiveServices/accounts/your-resource"
export SPEECH_REGION="eastus"

Install dependencies:

# run from this skill folder
uv sync

Quick Start

Verify SSML templates without generating audio:

uv run scripts/generate_voiceover.py --dry-run --content-dir path/to/content

Generate voice-over WAV files:

uv run scripts/generate_voiceover.py --content-dir path/to/content --output-dir voice-over

Embed audio into a PPTX deck:

uv run scripts/embed_audio.py --input deck.pptx --audio-dir voice-over --output deck-narrated.pptx

Parameters Reference

generate_voiceover.py

| Parameter | Type | Default | Description |

|:----------------------|:-------|:------------------------------------|:-------------------------------------------------------------------------------------------|

| --dry-run | flag | false | Print SSML templates without generating audio |

| --voice | string | en-US-Andrew:DragonHDLatestNeural | Azure TTS voice name |

| --rate | string | +10% | Speech prosody rate |

| --content-dir | path | content | Path to slide content directory |

| --output-dir | path | voice-over | Path to WAV output directory |

| --lexicon | path | *(auto-detect)* | Custom acronyms.yaml path |

| --collapse-newlines | flag | false | Collapse newlines and whitespace runs in speaker notes into single spaces before synthesis |

| --verbose / -v | flag | false | Enable verbose (DEBUG) logging output |

embed_audio.py

Embeds WAV files into corresponding PPTX slides and adds narration timing

XML so PowerPoint recognizes the audio for video export via

File > Export > Create a Video > Use Recorded Timings and Narrations.

| Parameter | Type | Default | Description |

|:-------------------|:-----|:------------------|:--------------------------------------|

| --input | path | *(required)* | Source PPTX file path |

| --audio-dir | path | voice-over | Directory with slide-NNN.wav |

| --output | path | *-narrated.pptx | Output PPTX file path |

| --verbose / -v | flag | false | Enable verbose (DEBUG) logging output |

Script Reference

Generate with custom voice and rate:

uv run scripts/generate_voiceover.py \
  --content-dir content \
  --output-dir voice-over \
  --voice "en-US-Jenny:DragonHDLatestNeural" \
  --rate "+5%"

Use a custom lexicon:

uv run scripts/generate_voiceover.py \
  --content-dir content \
  --lexicon custom-acronyms.yaml

Collapse newlines in speaker notes (recommended for block-scalar | notes,

whose line breaks are otherwise spoken as pauses):

uv run scripts/generate_voiceover.py \
  --content-dir content \
  --collapse-newlines

Embed generated audio:

uv run scripts/embed_audio.py \
  --input slide-deck/presentation.pptx \
  --audio-dir voice-over \
  --output slide-deck/presentation-narrated.pptx

Acronym Lexicon

The lexicon controls SSML <sub alias> replacements for acronyms and technical terms. Create an acronyms.yaml file:

acronyms:
  HVE-Core: "H V E Core"
  OWASP: "Oh wasp"
  SBOM: "S Bomb"
  SLSA: "Salsa"
  CI/CD: "C I C D"

Lexicon resolution order:

• Path specified via --lexicon argument.
• acronyms.yaml in the content directory.
• Built-in defaults covering common technical acronyms.

SSML Template

Each slide produces an SSML document:

<speak version="1.0" xmlns="http://www.w3.org/2001/10/synthesis"
 xmlns:mstts="http://www.w3.org/2001/mstts" xml:lang="en-US">
  <voice name="en-US-Andrew:DragonHDLatestNeural">
    <prosody rate="+10%">
      Text with <sub alias="Oh wasp">OWASP</sub> aliases applied.
    </prosody>
  </voice>
</speak>

Integration with PowerPoint Skill

This skill reads from the PowerPoint skill's content directory structure:

content/
├── slide-001/
│   └── content.yaml    # Must include speaker_notes: field
├── slide-002/
│   └── content.yaml
└── ...

Each content.yaml should contain a speaker_notes: field with the narration text. The generated WAV files are named slide-NNN.wav matching the directory names.

Troubleshooting

| Issue | Solution |

|:-----------------------------------------------------|:--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

| Set SPEECH_KEY ... or SPEECH_RESOURCE_ID | Export SPEECH_KEY (key auth) or SPEECH_RESOURCE_ID (Entra ID) with SPEECH_REGION. |

| 401 with Entra ID auth | Verify custom domain on the Speech resource and Cognitive Services Speech User role. RBAC propagation takes up to 5 minutes. |

| Empty WAV files or skipped slides | Verify speaker_notes: is present and non-empty in content.yaml. |

| Mispronounced acronyms | Add entries to acronyms.yaml with phonetic aliases. |

| azure-cognitiveservices-speech package is required | Run uv sync in the skill directory. |

| Audio icon visible in PPTX | Reposition or resize the audio object in PowerPoint after embedding. |

| Authored slide animations missing after embedding | embed_audio.py replaces existing p:timing with narration timing; re-apply animations in PowerPoint after embedding audio. |

| Slides no longer advance on click after embedding | embed_audio.py sets advClick="0" for auto-advance. To re-enable, select all slides in PowerPoint and check Advance Slide > On Mouse Click in the Transitions tab. |

| Video export shows "No timings recorded" | Re-embed audio with the updated embed_audio.py which adds narration timing XML automatically. |