Files
infiplot-web/app/api/beat-audio/route.ts
T
yuanzonghao ca73a41a0b feat(tts): StepFun voice selection via CharacterDesigner + provider-aware beat-audio
Make homepage cards and live sessions produce sound when the server is
configured for StepFun TTS, instead of silently failing (the prebaked
Xiaomi voice was useless on a StepFun server, and wasted ~220KB/beat in
Fast Origin Transfer).

Three coordinated changes:

1. CharacterDesigner now picks a StepFun preset voice id directly from the
   32-entry catalog in the SAME LLM call that designs the character — zero
   extra latency, LLM-grade match quality. The Xiaomi prompt path is
   byte-identical to history (verified programmatically) so cache hit rate
   and voice quality are preserved. pickStepfunVoiceId (keyword scorer)
   remains the fallback for orphan speakers / invalid LLM picks.

2. The 32-preset catalog moves to lib/tts-client/stepfun-voices.json as the
   single source of truth, shared by the scorer, the CharacterDesigner
   prompt, /api/tts-provider, and the offline enrich script.

3. A new GET /api/tts-provider endpoint lets the client probe the server's
   TTS provider at /play mount. fetchBeatAudio then shapes its request body:
   on a StepFun server it sends the lightweight stepfunVoiceId /
   voiceDescription and omits the ~220KB Xiaomi reference audio (FOT saving
   ~13MB per protagonist per session on prebaked cards). requestBeatAudio
   re-provisions on a provider mismatch before synth, so audio never goes
   silent on a cross-provider replay or mid-session provider flip.

New type fields are all optional and backward-compatible: Character.stepfunVoiceId,
BeatAudioRequest.voiceDescription/characterName/stepfunVoiceId, voice made
optional. AGENTS.md updated for the new route, type fields, dependency map,
and StepFun voice-selection flow.
2026-06-15 12:49:25 +08:00

52 lines
2.1 KiB
TypeScript

import { requestBeatAudio } from "@infiplot/engine";
import type { BeatAudioRequest } from "@infiplot/types";
import { NextResponse } from "next/server";
import { loadEngineConfig } from "@/lib/config";
import { requireUser } from "@/lib/supabase/guard";
export const runtime = "nodejs";
export async function POST(req: Request) {
const auth = await requireUser();
if (auth instanceof NextResponse) return auth;
let body: BeatAudioRequest;
try {
body = (await req.json()) as BeatAudioRequest;
} catch {
return NextResponse.json({ error: "Invalid JSON" }, { status: 400 });
}
// Voice is now optional — when the server runs StepFun, the client omits
// the ~220KB Xiaomi reference audio and sends stepfunVoiceId /
// voiceDescription instead (saves Fast Origin Transfer bandwidth). The
// engine's resolveVoice re-provisions on a provider mismatch. We only
// require the beat text + SOMETHING to synthesize from.
const VALID_TTS_PROVIDERS = ["xiaomi", "stepfun"];
const hasVoice =
!!body.voice?.provider && VALID_TTS_PROVIDERS.includes(body.voice.provider);
const hasFallback =
!!body.stepfunVoiceId || !!body.voiceDescription;
if (!body.beat?.id || !body.beat?.line || (!hasVoice && !hasFallback)) {
return NextResponse.json(
{ error: "beat.id and beat.line are required, plus either voice.provider (xiaomi|stepfun) or stepfunVoiceId/voiceDescription" },
{ status: 400 },
);
}
try {
const config = loadEngineConfig();
const result = await requestBeatAudio(config, body);
if (!result.audio) return new Response(null, { status: 204 });
const binary = Buffer.from(result.audio.base64, "base64");
return new Response(binary, {
headers: { "Content-Type": result.audio.mime },
});
} catch (err) {
// Engine already swallows synth errors and returns audio:null. Anything
// that reaches here is config-level — surface so the client can log it.
const message = err instanceof Error ? err.message : "Unknown error";
return NextResponse.json({ error: message }, { status: 500 });
}
}