From 6e6525a4160cdc80b94e5a3554e740057b5c30e4 Mon Sep 17 00:00:00 2001
From: Sharang Parnerkar <30073382+mighty840@users.noreply.github.com>
Date: Thu, 16 Apr 2026 21:44:12 +0200
Subject: [PATCH] fix(pitch-deck): pin presenter TTS to Edge TTS
 (de-DE-ConradNeural)
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German permanently routes to compliance TTS service (Edge TTS neural
voice, Piper fallback). OVH DE path removed — no env var can flip it
back accidentally.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 pitch-deck/app/api/presenter/tts/route.ts | 42 ++++++++---------------
 1 file changed, 14 insertions(+), 28 deletions(-)

diff --git a/pitch-deck/app/api/presenter/tts/route.ts b/pitch-deck/app/api/presenter/tts/route.ts
index 4e1b6cf..1436aad 100644
--- a/pitch-deck/app/api/presenter/tts/route.ts
+++ b/pitch-deck/app/api/presenter/tts/route.ts
@@ -4,28 +4,15 @@ const TTS_SERVICE_URL = process.env.TTS_SERVICE_URL || 'http://compliance-tts-se
 const LITELLM_URL = process.env.LITELLM_URL || 'https://llm-dev.meghsakha.com'
 const LITELLM_API_KEY = process.env.LITELLM_API_KEY || ''
 
-// OVH AI Endpoints TTS via the LiteLLM passthrough.
-// Path on the LiteLLM side: /tts-ovh/audio/*  →  https://nvr-tts-<lang>.endpoints.kepler.ai.cloud.ovh.net/api/*
-// OVH DE is opt-in: set OVH_TTS_ENABLED_DE=true to activate.
-// When disabled, German falls through to the compliance TTS service (Edge TTS → Piper).
-const OVH_TTS = {
-  de: process.env.OVH_TTS_ENABLED_DE === 'true'
-    ? {
-        url: process.env.OVH_TTS_URL_DE || `${LITELLM_URL}/tts-ovh/audio/v1/tts/text_to_audio`,
-        voice: process.env.OVH_TTS_VOICE_DE || 'German-DE-Male-1',
-        languageCode: 'de-DE',
-      }
-    : null,
-  // Enable by setting OVH_TTS_URL_EN (e.g. pointing at a second LiteLLM
-  // passthrough that targets nvr-tts-en-us). Keeps EN on the old path until set.
-  en: process.env.OVH_TTS_URL_EN
-    ? {
-        url: process.env.OVH_TTS_URL_EN,
-        voice: process.env.OVH_TTS_VOICE_EN || 'English-US.Female-1',
-        languageCode: 'en-US',
-      }
-    : null,
-}
+// English via OVH is opt-in (set OVH_TTS_URL_EN). German always uses the
+// compliance TTS service (Edge TTS de-DE-ConradNeural → Piper fallback).
+const OVH_EN = process.env.OVH_TTS_URL_EN
+  ? {
+      url: process.env.OVH_TTS_URL_EN,
+      voice: process.env.OVH_TTS_VOICE_EN || 'English-US.Female-1',
+      languageCode: 'en-US',
+    }
+  : null
 
 const SAMPLE_RATE_HZ = parseInt(process.env.OVH_TTS_SAMPLE_RATE || '16000', 10)
 
@@ -38,9 +25,8 @@ export async function POST(request: NextRequest) {
       return NextResponse.json({ error: 'Text is required' }, { status: 400 })
     }
 
-    const ovh = language === 'de' ? OVH_TTS.de : OVH_TTS.en
-    if (ovh) {
-      return await synthesizeViaOvh(text, ovh)
+    if (language === 'en' && OVH_EN) {
+      return await synthesizeViaOvh(text, OVH_EN)
     }
 
     return await synthesizeViaComplianceService(text, language)
@@ -115,7 +101,7 @@ async function synthesizeViaComplianceService(text: string, language: string): P
 }
 
 // Prepend a minimal 44-byte WAV header to raw 16-bit mono PCM.
-// OVH's Riva HTTP endpoint returns bare PCM samples; browsers need RIFF/WAV framing.
+// Used only for OVH EN if enabled — OVH Riva returns bare PCM samples.
 function wrapPcmAsWav(pcm: Buffer, sampleRateHz: number): Buffer {
   const numChannels = 1
   const bitsPerSample = 16
@@ -128,8 +114,8 @@ function wrapPcmAsWav(pcm: Buffer, sampleRateHz: number): Buffer {
   header.writeUInt32LE(36 + dataSize, 4)
   header.write('WAVE', 8)
   header.write('fmt ', 12)
-  header.writeUInt32LE(16, 16)        // PCM subchunk size
-  header.writeUInt16LE(1, 20)         // PCM format
+  header.writeUInt32LE(16, 16)
+  header.writeUInt16LE(1, 20)
   header.writeUInt16LE(numChannels, 22)
   header.writeUInt32LE(sampleRateHz, 24)
   header.writeUInt32LE(byteRate, 28)